Needle-nose pliers for zip tie trimming.
  • Needle-nose pliers for zip tie trimming.

  • 2.5mm Allen key for M3 screws

  • 2mm Allen key for nut alignment

  • 1.5mm Allen key for tightening the pulley

Can’t figure out how to let author know it took me 4 hours 45 minutes to complete. I’m probably a bit on the slow side and made a few slight errors along the way, so consider this a upper bound? Jakub Dolezal feel free to delete this once it gets read

timcdoc - Reply

I'm pretty quick and it took me 1 hour 15 minutes. Definately clean all holes on the printed parts before assembling using the smallest Allen key to speed things up. There were quite a lot of strings on the overhangs that break off easily with a tool but not with a nut. Also I found the hole for the bottom of the heatsink was not quite round enough, a touch of sandpaper brought that in nicely.

Chris Vahi - Reply

For the following steps, please prepare:
  • For the following steps, please prepare:

  • Extruder-idler (1x)

  • Bondtech pulley WITHOUT the lock screw (1x)

  • Pulley bearing (2x)

  • M3nS nut (2x)

  • Pulley shaft (1x)

  • Note there are two types of the Bondtech pulley in the package (one with and without lock screw). Make sure you are using the correct one.

For those who have a shocking moment here as it looks like one pulley bearing is missing… have a look inside the bondtech pulleys ;)

Stefan Lutz - Reply

Yuup!!! Same thing in my bag.

Douglas Shelfoon - Reply

When sorting through the pieces it appears I have an extra grub screw … the bondtech has one in place, and another is loose. Is it just an extra?

Rich - Reply

Same with the grub screw, extra?

Mark Moore - Reply

Press the nuts to the slots on both sides of the idler. Insert both bearings in the pulley. Be aware that bearings can slip out during assembly.
  • Press the nuts to the slots on both sides of the idler.

  • Insert both bearings in the pulley. Be aware that bearings can slip out during assembly.

  • Layers might be visible in this printed part due to the geometry. The functionality and strength remain unaffected.

There is no printed part here. Perhaps the comment should be on the next picture

Steve Worcester - Reply

Hi Steve, the black idler (first picture) is 3D printed.

Jakub Dolezal -

I am unable to get the right nut in far enough to put a screw through. Probing with an Allen key it feels like there is a blockage in one corner. Is there a good process to clean this out?

Frank Riddle - Reply

Hi Frank, to clean the slot I use the smallest Allen Key, it works pretty well.

Jakub Dolezal -

Ensure both bearings are inside the pulley! Insert the pulley in idler as shown in the picture.
  • Ensure both bearings are inside the pulley!

  • Insert the pulley in idler as shown in the picture.

  • Slide the shaft through the idler and pulley. Use reasonable force or you will BREAK the printed part.

  • Place your finger on the bearing and ensure it can rotate freely.

Any suggestions on how to get the shaft in? It’s impossible with my parts. Might have to try and ream out the hole.

Alex Tramiel - Reply

Since the shaft is 3mm - I´d suggest using a 3mm drill bit and widen up the first hole - by hand preferably.

Richard Rohan -

put the champfer-side into the hole (direction of the orange arrow is good) then take a wood or plastic on your workbench.

hold the printed part vertically and slightly push downwards.

Heiko Schultz -

Hi Alex, did you manage to press the shaft in?

Jakub Dolezal -

For me, the holes in the printed part were too small. I enlarged it with a small round file.

Michal - Reply

The hole can not be too big so that the shaft does not fall out.

Michal - Reply

No way to get this in by hand, but a pair of channel locks worked as sort of arbor press, and popped right in.

Scott - Reply

I drilled mine out and epoxied in the shaft. It was so tight I felt sure I would break the part before getting it in. I would rather have pressed it in, but it was just too tight!

Steven Underwood - Reply

Guys, feedback noted and production team alerted. Thank you :)

Jakub Dolezal - Reply

also, the shaft is about 3.6mm too short. I inserted it (sadly I read about the necessary drilling too late ;(( ) an now it’s flush on one side and still 3.6mm to go on the other side.

Guntor H - Reply

Hi Guntor, can you please share a picture? (http://manual.prusa3d.com/Answers) Thanks

Jakub Dolezal -

I hand-drilled the entry hole to widen it slightly but left the other hole as-is. It seems to have worked well for now.

Brandon Oprendek - Reply

I did the same as Brandon - it worked ok but the system needs improving here

Chris Tipney - Reply

Hi Chris, it is already fixed, but due to the amount of already shipped printers it will take some time. Sorry about that.

Jakub Dolezal -

Shaft is indeed a bit short but I used one of the allen wrenches to just push it in a little further so it has a bit of ‘flesh’ on both sides. Guess shaft could do with an additional 2mm in length (at least).

Jeroen - Reply

Same problems over here: Holes to tight and shaft to short

Another thing:

On the bag is only one part mentioned (1x Bontech). So at first I did not realised that there are two different parts

Gerhard Kunz - Reply

Hi Gerhard, it is written in the first step to use Bondtech pulley without tightening screw.

Jakub Dolezal -

Same as @kunzgbr - I had two similar looking parts in E-Axis bag which was labeled 1xBondtech. I notice now one of them has an allen lock screw, so I used the one without the lock screw for this step. Not sure if the other is needed or not yet.

Graham McIntyre - Reply

Hi Graham, yes for this step use the without the lock screw. It is written in the first step of this chapter.

Jakub Dolezal -

Too short by about the thickness of one of the hangers

Steve Worcester - Reply

Rubber mallet here, went just fine without drilling, but shaft could be 2 or 3 mm longer. I managed to make it equally spaced

Giacomo - Reply

Note: before leaving this step I would recommend you tap on the extruder and verify that the pin does not shift out of place. if the pin walks out, then you will not be able to generate good prints. It may be possible to add just a touch of super glue to the end cap to prevent the pin from walking out. Another option is to use a hot glue gun to secure the part in place. A longer pin would make this part more reliable.

Bradley Moreavek - Reply

Slight touch up with a small, round file…tight friction fit…equally spaced and then a drop of super-glue seems to have worked for me.

Matt Plummer - Reply

I used a big clamp very carefully to get it in, then I took the included screwdriver and drove the pin farther in by smacking the screwdriver with a metal wrench. Worked ok.

Mr Cookie - Reply

I just used the included pliers to press it in. Make sure the shaft is as straight/perpendicular as possible and use the pliers to press it in. One tip of the pliers is on the end of the shaft and the other is on the back side of the near tab (ie. the first one the shaft goes through) Once the shaft is flush with the inside wall or sticking out just a half mm or so you can put the gear in and press the rest of the way. This way the pliers support the printed part while pushing the shaft in. This minimizes the chance you will break the printed part. If you drill it out or file it, it will be easier to push in by hand but also easier for the shaft to work loose.

Also the shaft seems too short. Should be a mm or two longer as others have stated.

Bryan Jackson - Reply

It’s way easier to insert once you realize the shaft has one chamfered side you need to insert first. Then press the entire part down on the shaft, with the shaft resting on a wood surface. I pushed it in a little further using the philips head, that solved the length issue as well. Wouldn’t have known this without @predatorjr mentioning the chamfered edge on the shaft.

Bas - Reply

Good information Bas, Thank you. No need to drill. Just press the entire part on a wood surface.

Jacques Bourdouxhe -

Great Information Bas. Inserting the chamfered side first and a little tap-tap with pliers, and it when right in.

Paul Bowers -

Yes, knowing that one side of the shaft has slightly rounded edges (chamfered) compared to the other more square-cut end definitely made a difference. No issue pressing it in by hand. That said, as others have noted, 1-2mm of extra length would help the situation. Took a little careful back and forth to get the shaft centered between the two mounts.

Kalani - Reply

I could not get the shaft in. Slightly pressed it like others have set and broke one side. I’ll try and get it in and super glue it. Then try and print that part again for a replacement once the printer is working. This has been the hard part of the build for me.

Michael Aldrich - Reply

The shaft on my pre-assembled mk3 is indeed too short. After around 200 hours of use , I noticed my filament slipping no matter how much I tightened the idler. The shaft had slipped to the side allowing the idler to lose contact with the filament.

Robert Klein - Reply

This is still way too hard to get it and its from 3/14/18

Alex Paradis - Reply

Just press it against a table before putting the idler in. Keep your thumb over the hole. Once you feel the shaft start to come through, then put the idler in and press the rest of the way.

phr0ze -

Before you put the idler in, use your thumb to press the shaft into the first part. Just press the shaft against the table and you will feel it press in pretty easy. Now add the idler with the bearings and press the shaft the rest of the way on the table. However the shaft will still not be in enough. For the next step take a M3x10, add a nut to it and screw it in to expose 1-2mm of screw. This nut is a stopper. Balance the pin on the top of the screw and press it in so the pin goes far enough but not too far. If you have problems balancing the M3x10 you can use the hole in the center of the X Axis cover to hold the screw upright.

phr0ze - Reply

the shaft really should be a couple mm longer. It’s hard to center in the shaft and make sure it’s not going to wobble. I didn’t have any issues inserting, a little force got it done.

Jesse Brockmann - Reply

Agree with everyone else on this one. Shaft is too short by a couple mm and the hole is too tight to get the shaft into without a bit of modification. Highly recommend corrections to the design.

Dave S - Reply

The holes for the shaft were extremely tight, so I did not dare apply a strong force that would tend to break off one of the holders. I live in the US, and I don’t have a 3mm drill. So I drilled out one side only to 1/8”, which is 3.175mm, but I left the other side unchanged. This allowed me to easily insert the shaft through the modified holder, and through the idler pulley bearings. Then I could rest the other side on the edge of my work table and push the shaft into that side without risk of breaking the side off. As others have noted, the shaft is too short, so I used an M3 bolt as a “drift pin” to push the shaft further into the far side support, ending up with the shaft equally “indented” from each end.

Jay Sinnett - Reply

For the following steps, please prepare:
  • For the following steps, please prepare:

  • Extruder-body (1x)

  • Filament sensor (1x)

  • The filament sensor is in the box labeled "2.3.4.5 SUP".

  • BE CAREFUL with the filament sensor, do not touch the black PCB nor the chips on it.

  • M3x10 screw (1x)

  • M3n nut (2x)

The step 5 / PACKaging is not correctly labled — I have 2 large and a small package. One contains screws, the other the plastic parts, the small package contains the parts from step 2. I’m missing the filament sensor from this step.

PEB - Reply

corection - found it ….it is in the carton package. That should be mentioned in the description

PEB - Reply

Thanks for the suggestion, I'm working on something already ;)

Jakub Dolezal -

Definitely agree that you should mention that the filament sensor is found in the “2.3.4.5 SUP” box, and also mention that it’s in a static-protection envelope.

Bill Magley - Reply

Hi Bill, description was updated. Thanks for the feedback ;)

Jakub Dolezal -

It says not to touch the black PCB or the chips on it. What should we touch? Is it safe to hold by the edges or should we grasp the metal prongs?

Jason Coleman - Reply

Hi Jason, please hold the sensor on the edges.

Jakub Dolezal -

Its static sensitive ,only a problem on really dry days. you could ground your self ?

Phillip Kearney - Reply

Hi Philip, I suggest ground yourself first (touch some metal) and then hold the sensor only on the edges not on the sides with the chips.

Jakub Dolezal -

Current body version is B6 if you want to mention it’s different than the pictures.

Evan - Reply

Hi Evan,

No matter the version of the printed part the assembly process should be the same. In case our new version of the printed part changes significantly, the manual gets updated accordingly. Thanks for the suggestion ;)

Jakub Dolezal -

Before we continue with the assembly, we need to insert nuts in the Extruder-body. Take the extra time and effort to place them in properly. You won't be able to reach them later. Rotate the front part towards you and insert the M3 nut in the slot, all the way in.
  • Before we continue with the assembly, we need to insert nuts in the Extruder-body. Take the extra time and effort to place them in properly. You won't be able to reach them later.

  • Rotate the front part towards you and insert the M3 nut in the slot, all the way in.

  • Rotate the rear part towards you and insert the M3 nut in the slot, all the way in.

  • If you can't push the nuts in, use a longer screw from the other side and tighten it until you "pull" the nut in.

hint how to easily place nuts , just use one of M3 nuts you have from E package, screw nut with 1 turn on M3, place nut in the hole, check it is perpendicular, turn screw 1 turn back so nut is released, piece of cake, in the nut has to be deeper use longer M3 screw, you can use your thumb to press it in space

ufon - Reply

On my Part B3, the hole for the 2nd nut (the blue one) was oversized and the nut spun freely inside the part. I was able to use the flathead screwdriver to hold the nut in place while screwing it doen from the other side. When it was tight to the bottom of the hole the nut gripped the part.

Chris Pardy - Reply

I think this step can be moved to the end. I disagree with the note that you can’t add the nuts until the end because you can’t reach them later. The nuts kept falling out of the printed parts, so I left it until after step 18 IIRC with no problems.

Jon Le - Reply

Hi Jon, thanks for the suggestion. The reason for this order of steps is because of the filament sensor, which can be damaged while inserting the front (yellow) nut and forgetting there are pins on the other side. I’ve tested the assembly several times and these nuts were OK, I will recheck it.

Jakub Dolezal -

Step 6 M3 nut in front can’t be pulled down by M10 bolt, it isn’t obvious that this is ok? We don’t want anyone crushing the plastic trying to make this happen.

timcdoc - Reply

I noticed that if you push the nuts down all the way it is a snug fit and they don’t fall out. I tapped mine down with the phillips screwriver.

Larry Kmiecik - Reply

Carefully insert the filament sensor in the slot, do not use force or you might damage the PCB! Carefully insert the filament sensor in the slot, do not use force or you might damage the PCB!
  • Carefully insert the filament sensor in the slot, do not use force or you might damage the PCB!

Add Comment

Turn the extruder-body like in the picture. The pins of the filament sensor must be facing up. Locate the opening for the M3 screw.
  • Turn the extruder-body like in the picture. The pins of the filament sensor must be facing up.

  • Locate the opening for the M3 screw.

  • Take the M3x10 screw and tighten the sensor in place. No nut is needed, the screw will self-tap into the plastic.

  • The sensor must be tightened completely to prevent its movement BUT BE CAREFUL during tightening to avoid damage to the sensor.

  • Layers might be visible in this printed part due to the geometry. The functionality and strength remain unaffected.

Does the head of the screw touch the sensor? I seem to be screwing into plastic and I’m not sure how far to go with it.

Mark Abrams - Reply

Hi Mark, the head of the screw must touch the PCB of the sensor. Be careful during tightening ;)

Jakub Dolezal -

There is an issue. No filet in the pcb and not enough space between the pcb and the plastic part to put a nut. So you must carefully make a hole with a drill (in screw direction) to have enough space to put a nut. But Prusa has to modify the manual and the parts.

Xavier - Reply

There is no nut involved when fixing the sensor, the M3x10 bolt is self-tapping into the plastic.

Robert Hunt -

Hi Xavier, as Robert said, there is no need for a nut, the screw will self-tap into the printed part.

Jakub Dolezal -

I was able to secure it fully by continuing to screw into the plastic until the screw head presses snuggly against the sensor. I think it would be useful to other makers to show the result from the left side (based on the current photos as “front facing”) to show what to look for.

Mark Abrams - Reply

Hi Mark, thanks for the feedback. I will consider extra picture to show properly tightened sensor.

Jakub Dolezal -

Hi. I noticed the senzor itself (sensory part) is looking dirty. Probably I should no attemp to clean… Or?

Juraj Mr. - Reply

Hi Juraj, the sensor shouldn't be dirty otherwise it won't recognise the filament correctly. Best is to use compressed air, in other words avoid direct contact with the sensor.

Jakub Dolezal -

I was also a bit confused that there was no nut trap/nut for this assembly. It might be wise to include a comment in the instructions when you have screws going directly into plastic. There are a few other screws that are used this way. It would be good to have a heads up. Also since M3 screws in plastic can easily strip, a warning not to over-tighten would be good.

Bryan Jackson - Reply

I agree. I was trying to figure out where I missed a step about installing a nut, but then I saw the comments. A note that it screws into the plastic would be nice.

Guido Kimble -

Wich type of nut we have to add and were please

Sébastien ROUSSELLE - Reply

Hi Sébastien, no nut need for this step.

Jakub Dolezal -

I also agree - it would be good to mention that the screw is going into plastic. After the screw failed to bite a few times, I removed the filament sensor and got the screw started with a few threads, then I removed the screw and reinstalled the filament sensor. The screw was much easier to start after that (still being careful since it’s going into plastic). I’m not extremely confident that I have the screw tightened enough, yet not too much - the sensor seems to be fixed in place, so I’m stopping there.

Bill Magley - Reply

For the following steps, please prepare:
  • For the following steps, please prepare:

  • M3x30 screw (1x)

  • M3 translucent washer (2x)

  • Translucent washers are placed on the idler, due to better visibility for the viewer. No need to place them as in the picture ;)

Picture in Step 9 is a bit confusing, this part is not in the MK3 kit in this form ;-)

Jeroen - Reply

Hi Jeroen, since the washers are transparent, some darker background was needed ;) and you will use the idler in the next step anyway.

Jakub Dolezal -

Being a bit pedantic here, but the washers are translucent, not transparent :P

H4irBear - Reply

Hi, yes you are right, thanks for the correction ;)

Jakub Dolezal -

Turn the Extruder-body like in the picture. The pins must be facing to the right. Insert M3x30 screw in the hole.
  • Turn the Extruder-body like in the picture. The pins must be facing to the right.

  • Insert M3x30 screw in the hole.

  • Place a washer from the other side.

  • Assemble the idler on the M3x30 screw.

  • Finish the assembly with the second washer.

only one washer in picture use. please arrow secound washer on picture

theerachai - Reply

Look at both photos for Step 10. It’s between the extruder body and the idler.

J Allen -

Hi, first washer is marked with green arrow, second washer with orange circle. Please, check the pictures again ;)

Jakub Dolezal -

How tight should I tighten the screw?

Raynald Bijosono - Reply

Hi Raynald, you can’t tighten the screw right now as there is no counterpart. However, this screw is holding the idler, so later on, don’t tighten it too much. The idler must be able to move/rotate.

Jakub Dolezal -

I used a nut temporally do hold the second washer on place. This after I dropped it two or three times to the floor and had to search it ;-)

Wolfgang Peters - Reply

For the following step, please prepare:
  • For the following step, please prepare:

  • Extruder motor (1x)

  • Bondtech pulley WITH the lock screw (1x)

  • Ensure you are using the correct motor, there is a label on the bottom of the casing. The reason is, each motor has different cable length.

  • There is a second spare lock screw in the package.

Ah, this is the other Bondtech not noted on the 5.E-Axis bag. This should be noted and also a special note above for the first Bondtech to use the one with no set screw.

Graham McIntyre - Reply

If you are upgrading from MK2S, remove the old extruder-gear/pulley

Michael Hermes - Reply

There is a flat part on the motor shaft, rotate it towards you. Slide the pulley on, note the CORRECT orientation.
  • There is a flat part on the motor shaft, rotate it towards you.

  • Slide the pulley on, note the CORRECT orientation.

  • The screw must be facing directly against the pad (flat part) on the shaft. Slightly tighten the screw, the final adjustment will be done later.

  • Don't press the pulley against the motor. Leave it on the very top of the shaft, see the picture.

This step and picture should be revised to show the motor shaft flat and pulley rotated 90-degrees clockwise (set screw facing to the left, in the current picture). In the orientation this step requires currently, you end up being unable to access the set screw in the next step without turning it.

Guido Kimble - Reply

Hi Guido, good point. For now, you can rotate the shaft even if assembled in the extruder body. Use pliers.

Jakub Dolezal -

Find in the package two M3x30 screws and insert them into the holes. Before mounting the motor, ensure the second translucent washer is still on the   top M3x30 screw.
  • Find in the package two M3x30 screws and insert them into the holes.

  • Before mounting the motor, ensure the second translucent washer is still on the top M3x30 screw.

  • Mount the motor on the extruder body as shown in the picture, double check the proper orientation of the motor cables.

  • Tighten both screws firmly.

  • Tighten the screw, but only slightly, keep in mind the idler must rotate freely.

It's easy for the outer nylon washer to fall off when doing the steps between step 10 and here. Maybe put in the other 2 30mm screws first? Or at least note here to make sure the nylon washer is still in place.

Graham McIntyre - Reply

Thanks Graham, note added.

Jakub Dolezal -

I agree with Graham, the outer washer from stem 10 might be moved to step 13 to avoid losing the washer each time the piece is rotated.

Carlos Rusconi - Reply

It doesn’t seem like there are too many threads that catch the stepper motor for the screw for the idler.

Ira Schonfeld - Reply

It says the idler must rotate freely. I assume that means you can “close it" so it fits inside the extruder body?

Even with the screw loose it feels like it's bumping over two or three ridges as the idler moves over the extruder body.

Jeff Spencer - Reply

Hi Jeff, the idler must be able to move a bit, because when you insert the filament it will push the idler a bit out. However, without the filament inside, the idler should be “closed fully” (aligned with the extruder body).

Jakub Dolezal -

Doesn’t make a huge difference, but this section deviates from the “Please prepare” step that the rest of the guide does.

Evan - Reply

Hi Evan, thanks. I'm aware of these steps and will “correct” them soon.

Jakub Dolezal -

Open idler fully to have direct access to the pulley. Use a piece of 1.75 mm filament (from the spool) to align the pulley with the openings for the filament (see the picture). Arrows only indicate the direction.
  • Open idler fully to have direct access to the pulley.

  • Use a piece of 1.75 mm filament (from the spool) to align the pulley with the openings for the filament (see the picture). Arrows only indicate the direction.

  • Adjust the pulley and tighten it with 1.5mm Allen key. Use reasonable force as you might damage the thread.

  • When ready with the alignment, please remove the filament.

Adjusting the pulley and tighten it with 1.5mm Allen key failed as both Allen keys stripped at very low force. I used my own.

Valentin Bulbuc - Reply

Same here, the included allen wrench is not working. Had to use my own.

Alexander Buschek -

Do we remove the filament peice after? I’m just finding out I need to remove it to insert the e3D hot end later on

Alex Wilkie - Reply

Hi Alex, yes please. Remove the filament when done with the alignment.

Jakub Dolezal -

It would be nice if there were more pictures showing the feed path of the filament from other angles.

Gabe Yoder - Reply

Hi Gabe, from these pictures you can see most of the “filament path”, other angles always cover something. What issues do you have with the aligning?

Jakub Dolezal -

The black pieces of extruded plastic included in the box are NOT filament. I fiddled with how to get these to route through for a little while before opening my box of actual filament. Adding a note here wouldn’t hurt to have someone else avoid my mistake.

Joe

Joe Pighetti - Reply

This threw me off as well. I was about to get a drill before I read your comment.

Travis Howard -

Hi Joe, that is why it is said to use a filament from the spool.

Jakub Dolezal -

For clarity, you might mention that a piece of orange filament is used in the picture to show the routing, and the green arrows are parallel to the correct path.

Bill Magley - Reply

Please just include a 100mm piece of filament in the bag for the step. Save so much time.

phr0ze - Reply

Agree it’s hard to see where to insert the filament from the back … a top view with an arrow of where to insert would help. I see now it inserts right next to the sensor.

Rich - Reply

In my case the filament (yes, from the spool) didn't fit through the small hole, it got stuck. So I widened it with a 2mm drill bit. I hope that's no problem?

Tako Schotanus - Reply

Hi Tako, small diameter increase should be fine.

Jakub Dolezal -

For the following step, please prepare: M3x40 screw (2x) Extruder spring (2x)
  • For the following step, please prepare:

  • M3x40 screw (2x)

  • Extruder spring (2x)

  • Assemble springs on both screws, see the second picture.

  • Close the idler, so the screws can reach it.

  • Place both screws into the Extruder body and tighten them. The screw's head should be almost aligned with the printed surface.

Are we supposed to close the idler first here?

Neal Tibrewala - Reply

Hi Neal, yes you must close the idler first as the screws must reach nuts inside the idler. Step instructions updated.

Jakub Dolezal -

So what distance should the screws be tightened for optimal grip/release? Almost flush? Is there a more scientific method to this, or does it not matter that much.

Douglas Shelfoon - Reply

Hi Douglas, on MK3 align the screws with the surface of the printed part. We've improved the design this way, so no special measurement is needed.

Jakub Dolezal -

Impossible to tighten even slightly on the part i received, the idler had no thread and the screw/bolts just slip though….

It would be better to use a metal nut here since the printed part was useless

Tom - Reply

Hi Tom, You might have missed step 3 first picture? There should be nuts in the idler.

Orne Brocaar -

Thanks Orne,

Just now saw the 2 holes for the square nuts as you said, so it was my fault being stupid :(

Great news though, I can continue building now :))

Tom -

Is this supposed to mean align the top or bottom of the screws head? I'm now assuming you mean bottom. If so, can you revise it to say “The bottom of the screw's head should be almost aligned with the printed surface.” ? I originally assumed it to mean the top of the screws head and it's been causing me issues with my filament breaking for days because my gears were way too tight. It's actually hard to tell from the pictures how is lined up.

Andre Fowler - Reply

So top or bottom of the head? If I set it to the bottom of the head, the spring has almost no tension.

Ira Schonfeld - Reply

I was not sure either. So I put the filament back in again. While tightening the screws I push and pulled on the filament until it feels right. OK, not really a scientific method, but it turns out I had a good grip with the screw head TOPS just above the printed part. Hope I’m not wrong, let’s see later :0

Quentin -

The screws “extrude” from the back as two small 2-3mm bumps post the idler - is that what expected?

Peter Larsen - Reply

Any closure on whether it’s the top or bottom of the screws’ heads?

I did closer to the bottom and seem to be getting good tension on the filament.

Evan - Reply

Hi Evan, the screw heads should be almost aligned with the surface, but this is something you will adjust during the prints and also in case you buy filament with larger diameter (larger tolerance), you might need to adjust it again.

Jakub Dolezal -

It might be good to remind people that the back side of this part looks similar to the correct side (a hex opening over two holes) so if you aren’t paying attention and accidentally put the screws in the wrong side you can get the screws compeletely past the threads such that they can’t be removed without destroying the 3D printed part.

Don’t ask me why I know this……

(I had a friend re-print me the part, after a 30 minute freak-out)

Brian Bishop - Reply

Take two M3nS nuts from the package and insert them in the slots, all the way in. Check proper alignment with the 1.5mm Allen key.
  • Take two M3nS nuts from the package and insert them in the slots, all the way in.

  • Check proper alignment with the 1.5mm Allen key.

Minor nit, I missed this step and inserted the nuts after the hot end was attached. Maybe put a picture of two M3nS nuts with green arrows, like is done in the rest of the manual? There is enough information to figure this out, but having the extra cues would help.

timcdoc - Reply

Hi Tim, this step will be updated. Thanks for the suggestion.

Jakub Dolezal -

Yeah, when 95% of the rest of the manual has a “prepare X, Y, Z” step it throws you off for the 5% of the time it doesn’t.

Evan - Reply

Hi Evan, I will update these steps soon.

Jakub Dolezal -

For the following steps, please prepare: Extruder-cover (1x)
  • For the following steps, please prepare:

  • Extruder-cover (1x)

  • M3nS nut (1x)

  • M3n nut (1x)

  • M3x25 screw (2x)

  • Insert both nuts in the printed part.

  • In case you can't press the M3n nut in, don't use excessive force. Take M3 screw thread it from the opposite side of the printed part, as you tighten the screw, it will pull the nut in. Be careful not to break the printed part during tightening.

In case you can't press the M3n nut in, don't USE excessive force.

Keith Manley - Reply

Thank you Keith, corrected.

Jakub Dolezal -

I cannot manage to fit this in whatsoever. The screw trick does not seem to be working whatsoever in getting the m3n nut in. Is there any better advice for this?

Kyle Campbell - Reply

EDIT: It eventually worked after brute force involving a rubber mallet.

Probably not the best idea though…

Kyle Campbell -

Hi Kyle, the “screw trick” should work always, but you need to ensure three things:

1) the thread is on the entire screw

2) there is nothing blocking the nut from going down

3) nut is aligned with the shape of the slot

Jakub Dolezal -

I had a bit of a problem getting the M3nS (square) nut in the hole. It was really tight and I had to poke in the hole with a small Allen key and also a bit with the Phillips screw driver to clear it just enough to be able to push the nut all the way in using some force pushing it in with the screw driver.

Kari Söderholm - Reply

Hi Kari, we are checking the printed parts before shipping them to you. However, sometimes it might happen there are some residues, which are blocking the nut. Use the smallest Allen key, to check it out and if needed clean them.

Jakub Dolezal -

Take the E3D hotend and place it inclined into the Extruder body. Make sure the white PTFE tube fits in properly. Insert the hotend into the Extruder body, see the picture.
  • Take the E3D hotend and place it inclined into the Extruder body. Make sure the white PTFE tube fits in properly.

  • Insert the hotend into the Extruder body, see the picture.

  • Make sure the hotend is fully seated and the upper part aligned (almost in contact) with the surface of the printed part.

  • Note the CORRECT orientation of the hotend.

  • Be VERY CAREFUL with the hotend wires from now on, you can damage them.

The PTFE tube insertion should be its own step prior to this one, please.

RWReese - Reply

Nevermind, please.

RWReese - Reply

What should be another VERY CAREFUL point here is to pay attention to the hot end being inserted ALL the way. Pay close attention to the final picture and how far in the hot end is. Mine was not in all the way. It went together and all was good until the XYZ Calibration. Yikes! Took 2 weeks to finally figure out what the heck was wrong. Finally got it thanks to the build forums.

Mike Kwiatkowski - Reply

You should perhaps mention that the white tube will need to bend a bit for you to be able to get the hot end all the way in.

Andreas Sjolund - Reply

The manual says, “Push the hotend into the Extruder body, see the picture”. What it should say is “Insert the hotend into the Extruder body so it fits around the collar in the Extruder body. This will make the bottom of the hotend even with the Extruder body.”

This little misstep on my part caused 10 days of total frustration because when I ran the XYZ calibration it always failed with the message “XYZ Calibration failed, check the axes”. So that what I did but it had no relationship to the axes. It was a hotend location problem.

E Duane Rose - Reply

Hi Duane, I'm aware of this and we are already working on a new design, but you are right. The instructions will be updated ;)

Jakub Dolezal -

I had to take mine appart after it failed at calibration. So making it easier to fit the extruder body and cover to make it easier to fit in the correct position would be a massive improvement.

Martin Wolfe - Reply

Ditto. Thankfully, it only took hours to fix and not days. I realized there was a problem after I attached the the wire routing when the nozzle was loose and rotating freely. Still, it should be more difficult to snap on the extruder cover if the extruder is not in the right position. It’s never fun disassembling a part immediately after spending an hour assembling it.

Mahir Abrahim - Reply

It was ten days for me as well. After failing XYZ calibration, I noticed I was repositioning of the P.I.N.D.A. probe a lot. Then when I found that 6-8” of filament disappearing inside the extruder. I decided to run the extruder motor until the nozzle started to extrude filament or something physically come out. The nozzle was what came out. I then knew, I needed to open up the extruder block. Went back to the online page for the extruder nozzle assembly and found the same error codes I had by your comments. I then remember being unsure of putting this part together. I ended up taking out the PTFE tube from the nozzle assembly and reinserted that first into the plastic body case and pushed it into the hole and up to the Bondex gears. I then inserted the extruder nozzle over PTFE tube and then was able to place the aluminum nozzle easily into place. I put the unit back together and the printer calibrated then properly.

Thanks for your comments it make the difference!!!

Frank De Abreu - Reply

Is the Hotend from the MK2S (which has my Olsson ruby) the same as the one in the MK3 upgrade? I’m trying to avoid changing the nozzle

Thanks, Stuart

Stuart Kurtz - Reply

Contacted Support. It is different a Voltage. ?24V vs 12V. Installed ruby prior to assembly> I’ve realized what is ultimately needed is a quick change nozzle system to accommodate different sizes for different print types. The current nozzle change system is too difficult to make swapping a print nozzle a regular experience .

Stuart Kurtz - Reply

Hi Kurtz, there are some significant differences, you have to use the MK3 hotend.

Jakub Dolezal -

I made the same mistake of not having the hotend flush with the extruder body. I didn’t realize I made that mistake until I went to calibrate the PINDA probe and realized the hotend was sticking out way too far. Took me about 30 minutes to take apart the extruder and install the hotend correctly. Getting the hotend to fit right wasn’t easy, I had to bend the ptfe tube just the right way to get it to fit. I may be oversimplifying the problem but it would be nice if the hotend could only fit in the extruder body only one way. Other than this one problem the assembly of my printer went smoothly and the printing is perfect.

M Goddard - Reply

Is our E3D V6 supposed to arrive without the blue collet clip? If you look at Step 18 on their assembly instructions, this part is included. I am only seeing the black collet and PTFE tube on my V6 here. https://e3d-online.dozuki.com/Guide/V6+A...

Todd Scott Anderson - Reply

I found a decent clip on thingiverse. Also I removed the tube and made sure everything inside was clean. the loose collet’s teeth had made a couple little ptfe strips and the bottom of the tube wasn’t exactly square. Removed the fluff and fixed the bottom.

The initial collet ring’s dimensions were a bit flimsy so I scaled it X, Y, Z : 0.95, 0.96, 1.2

https://www.thingiverse.com/thing:127662...

Todd Scott Anderson -

Rotate the extruder as shown in the picture. Take the extruder-cover and place it on the extruder body. Both printed parts must be in direct contact. Using M3x25 screws tighten both parts together.
  • Rotate the extruder as shown in the picture.

  • Take the extruder-cover and place it on the extruder body. Both printed parts must be in direct contact.

  • Using M3x25 screws tighten both parts together.

  • Ensure again the hotend is properly assembled. The surface of the heatsink (part of the hotend with cooling ribs) must be aligned with the surface of the printed parts. See the last picture.

On the last step of this part, using the 2 screws to tighten both parts together, I accidentally got the screw and nut cross thread. Now, the nut just turns in the 3D printed part and they’re stuck. I think you should use a longer nut or better quality nut so they don’t get cross thread. Like a coupling nut.

Bob - Reply

With the hot end in and the two parts together, the outside part rocks, as of there is some interference. I had to clean up a bit of the inside of the extruded cover and had to use a 30mm on the right side. A 25 mm wouldn’t even contact it

Steve Worcester - Reply

I agree. M3x25 was too short on that right side. Had to go with a 30

Christopher Tilley - Reply

M3x30 here, too.

RWReese - Reply

M3x25 worked for me.

David Beach - Reply

I also had to use 30mm, the 25mm would not grab the nut

Dennis Sladek - Reply

25mm were ok for me.

Andreas Sjolund - Reply

I got the same problem as Bob. The 25mm screw started to go cross thread and the nut started rotating in the printed part (as the nut wasn’t completely straight) without tightening. I was luckily able to get it out by pushing on the nut with the Phillips screw driver to keep it from rotating while unscrewing the screw. Then I used a 30mm screw to get it more easily on the correct thread.

25mm screw might work ok if you get it perfect, but I think it’s just easier to use a 30mm screw here and even putting in the screw first and then the nut it was easy at this point. Still the screw is totally inside the printed part. I would suggest switching to 30mm screw here for more foolproof assembly.

Kari Söderholm - Reply

Guys, thank you for the feedback. 25mm screw should be enough, but we will adjust the design for easier assembly.

Jakub Dolezal - Reply

The last statement in RED is a important point. Be sure to make this check as you assemble the extruder housing. if your installation is incorrect it will show up as an axes error when you do the XYZ Calibration.

E Duane Rose - Reply

Thanks Duane for your comment. I read it and quickly realized I needed to back up and reassemble the Extruder Cover. Removing the E3D Hot End took quite a while because the white PTFE tube was stuck. My solution was to enlarge the hole for the PTFE tube and then use a Dremel tool to widen the interior of the Extruder Cover so the two halves would fit around the E3D Hot End without rocking or stripping screws.

Bill Waring - Reply

The M3x25 screws worked for me. I actually had hard time positioning the Extruder Cover around the Heat Sink, it all looked misaligned. Eventually I inserted the two M3x25 screws all the way in into the Extruder Cover, and using them as guides towards their nuts managed to align everything properly and to tighten the two screws (hope the later Calibration step will pass OK!). It is a rather delicate step…

I read in the messages above that two of you had problems with “misaligned” nut. Maybe it helps to someone reading this, but I discovered one “M3” nut that would not fit., no way I had problems with it, tried several M3 bolts, it would not work. Then I took it out and tried it with several M3 bolts just to test it, nut and bolt only. None worked. I believe that nut is not Metric! It got somehow mixed in, and I was fortunate not to force it and create a bigger problem with some part…

Alan Rusyak - Reply

M3x25 worked for me, eventually. Biggest issues were:

1) Realizing just far down the hole those nuts need to be placed. It helps to pre-thread the two screws into the cover as far as possible, and checking the depth the head CAN reach. Hold the cover to the side, and you’ll see the screws DO stick out approx 1/4”, which is easily enough to catch the captured nuts IF they are also sunk as far in as they are supposed to go. Not easy, but it works.

2) Also, for me, I needed to realize that we’re not trying to catch BOTH of the square nuts on the left side (looking at the photo above), only the closer one. I assume the farther one has yet to be used, but will be soon.

Kalani - Reply

I’m worried about the hot end wires bouncing around while they are still bundled. Is this a good time to cut the zip tie holding all the wires in a bundle, or is it safer to leave it tied up? for now? (I realize the zip tie holding the two hot wires should probably stay)

timcdoc - Reply

Just an idea… once I had finished this assembly, I noticed that I had bent the delicate pins of the the filament sensor. Would it not be a good idea to include a little plastic cover that can be slid on to protect the pins at this fiddly stage?

David - Reply

Here is how I captured the nut: use a longer screw on the nut side, but only grab 2 threads. Use that screw to push the nut against the M3x25 coming from opposite dir3ction until the 25mm grabs the nut, then back out the screw that is barely attached, then finish tightening the 25mm screw.

Rich - Reply

To get the M3x25 to work on the right side, I first used an M3x30 and by tightening that it pulled the receiving nut in all the way inward … I then removed the M3x30 and was able to screw in the M3x25.

Gerry P - Reply

The left side fits perfectly with the M3x25 but the right side does not go all the way. Seems like its block after 3/4 of it… what do I do??

Pablo Traversat - Reply

M3x25 fits fine. When you put the nut in (Step 6) it says to put a longer nut in from the other side and tighten it up to pull the nut further in.

I used an M3x18 and that was enough to get the nut all the way in. If your M3x25 is not reaching, give that a try.

SteveP - Reply

Nut traps for M3 nuts are the bane of my existence. Had the same issue on the Mk2. Some nuts just don’t stay put…

Cristian Sandu - Reply

For the following steps, please prepare: M3x18 screw (6x)
  • For the following steps, please prepare:

  • M3x18 screw (6x)

  • Left hotend fan (1x)

  • Front print fan (1x)

  • The left hotend fan has two sides, but the side with sticker must be always facing the hotend (not visible when the fan is mounted). Otherwise, the cooling won't work properly.

Bolting on the Front print fan took me a lot of time because I could not get the nut inserted far enough (so the 18mm screw was too short to ‘reach’. 10 minutes of careful scraping/cutting and pulling later the connection was established ;-)

Jeroen - Reply

I suggest using a m3 washer on each m3 screw holding in the front print fan to avoid cracking the casing of the fan at mount points.

Natalie Crandall - Reply

Hi Natalie, thanks for the suggestion. For each fan assembly there is a warning regarding cracking the plastic cover while tightening. If you follow the instructions, you will be fine :)

Jakub Dolezal -

I’m guessing this is a good time to unroll the fan wire, but maybe a note saying it is, or it isn’t.

timcdoc - Reply

I would recommend taking a second to check the condition of the terminals on both of these fans. My print fan had a burnt and broken connection to the yellow terminal and I didn't find out until I put everything together and did cable management.

Ryan Latimer - Reply

Hi Ryan, fans are tested in our factory before shipping, but I forwarded your findings to my colleagues. Please contact our support for a replacement (info@prusa3d.com).

Jakub Dolezal -

Place the Extruder on the side and guide the wires from the motor in the slot. Place the Left hotend fan on the Extruder. The cable must be placed in the top left corner, see the picture. Note the correct orientation of the fan. The sticker has to face towards the hotend!
  • Place the Extruder on the side and guide the wires from the motor in the slot.

  • Place the Left hotend fan on the Extruder. The cable must be placed in the top left corner, see the picture.

  • Note the correct orientation of the fan. The sticker has to face towards the hotend!

  • Insert M3x18 screws and tighten them slightly.

  • Now, tighten ALL screws, but on a diagonal. After tightening check, the fan can rotate freely.

  • DON'T tighten the screws too hard, all parts are made of plastic and you can break them.

turn the fan so the cable go out to the rear of the carriage

Heiko Schultz - Reply

Hi Heiko, thanks instructions were updated.

Jakub Dolezal -

Not sure where to route the extruder motor wires after they’ve been routed through the slot, as indicated in picture 1.  I currently have them running down the back of the noctua fan and in the slot so it can be routed behind the extruder and wrapped.  In other photos the motor wires are not visible from the back of fan so I’m not sure if there was a step that I missed?

The wires are as snug as I can get them routed around the noctua fan but I'm afraid that they may come loose in time and make contact with the belt.  I think better pictures of the cable routing for the motor could help.  I’ll remove the noctua fan and see if there’s anything I missed.

Corey Dryja - Reply

I think I found the answer to my question and I may have asked my original question out of order.  It looks like there is a slot on the x-carriage that the extruder motor wires are supposed to run through that sits on the side of the fan.  This is not the slot that’s detailed in the steps below.

Corey Dryja -

In this step it calls for M3x18 screws for the Nactua fan. I didn’t like how in the second picture the screw that is inserted near the edge by the heater cartridge protruded. It was really close the thermostat wires. I replaced it with a M3x12mm. Later I will switch it to a M3x14mm for better anchoring. Prusa Team may want to look at that.

Donnell - Reply

Hi Donnell, thank you for the feedback. The design is safe and working if the printer is built according to the instructions. Longer/shorter screws might be working as well, but I can't guarantee it and also it will be extra screw size in the package. We tried to lower the amount of sizes across the entire build.

Jakub Dolezal -

The protruding screws were also unexpected for me, as every screw so far in the build has been of perfect length. Maybe a clarification in the instructions would be welcome.

Andreas Sjolund - Reply

You might mention these are plastic self taps….

Rich - Reply

Why is the cable location for the fan described as top left? As you face the fan it is more like bottom right. It would be nice to show a picture if it is intended to be close to the extruder motor wire bundle coming out of the groove.

Charles L Miksch - Reply

Hi Charles, if the extruder is mounted, then the cable is in the top left as described in the instructions.

Jakub Dolezal -

“Top Left” corner doesn’t really make sense when the extruder is laying on its side. Perhaps “The fan wire should be next to where the motor wire was just placed in a channel.” Especially since no image was shown from the side where the wire could actually be seen on the fan.

Dave S - Reply

Rotate the Extruder as in the first picture. Mount the Front print fan using two M3x18 screws.
  • Rotate the Extruder as in the first picture.

  • Mount the Front print fan using two M3x18 screws.

  • DON'T tighten the screws too hard, all parts are made of plastic and you can break them.

Myself and at least a few other users have run into the self test X axis failure due to the fan or extruder wires slightly sticking out behind the fan where the extruder carriage will pinch these wires when it runs into the left Z axis bracket. It would be helpful to new users to show a closeup of how the fan & extruder motor wires need to be tucked into the slot that runs over & behind the fan.

Jason Livingston - Reply

not into the slot, the slot is fine for the extruder cable, but the fan wire is too thick.

the MK2(s) fan cable is without '''cable sheath''' and would fit into. To push both wires into the slot on the MK3 would result in high pressure to the wires.

I’ve guided them directly out at the back of the carriage.

At step 21 you can see the wire and the cutout at the fan

https://picload.org/view/drprorai/2017-1...

Heiko Schultz -

Hi Jason, cable management for extruder cables starts at step 24. It is shown you need to place the cable inside cable clip and then inside the slot on the X-carriage, but I will recheck this part again.

Jakub Dolezal - Reply

the top M3x18 screw is too short. And no, there is nothing blocking the nut ;((

Guntor H - Reply

Hi Guntor, are both nuts properly installed? You can use longer screw to pull them closer and then replace with M3x18.

Jakub Dolezal -

I Had the same problem. The M3x18 is just a millimeter or two too short. I went for a longer screw from the spares. Doesn’t look perfect, but should work perfectly.

Pål Driveklepp - Reply

Same problem with the top m3x18 bolt (or screw if you prefer), it is too short - I used a 20mm one I had for another project

Chris Tipney - Reply

I had today the same problem - i fixed it with a lighter - just screw the nut (in the sparepart) on a screw and heat them a little bit (not to hot!!!) and pull them into the hole (just a little bit) - thats works perfect ;)

Greetings,

Max

Max007 - Reply

thanks for that (frightening) tip! works! better would be a 20mm screw!!!

Christoph Stahl -

I had the same problem with the one screw seeming too short. After I tightened a 20 mm screw in, I noticed there was about 2 mm sticking out and I was able to take it out and put the 18 mm one in. So, I t is just barely long enough and the nut has to be completely seated which I wasn’t able to do without the slightly longer screw to tighten it in.

Ross Stenersen - Reply

Use long screw, tighten it, remove and replace with correct one works for me.

Jan Tomek - Reply

I did the same as Jan above, worked great

Alistair - Reply

The seam on the fan popped open on me when I tightened the screw down. No big deal but now the fan has a little crack on the mounting hole. A bigger screw that overhangs the fan mounting hole a little more would help with that, or a washer. I think the M3 head is almost small enough to fit in the mounting hole so it exerts a side force on the fan housing when tightened. I was not over-tightening, it popped pretty early. Fortunately the fan requires very little force to hold it on so even with the crack I was able to loosen the screw a bit and still keep it in place just fine.

A warning to tighten very gently would be good.

Bryan Jackson - Reply

Be careful out there. I over-tightened the screw on the “crows nest” which cracked the very delicate fan housing. Just a small crack, though and it’s still quiet as a mouse FWIW.

Andreas Sjolund - Reply

The M3x18 screw is long enough. Use the top of a longer screw to press the nut in while screwing in the M3x18.

Edwin Martin - Reply

it was exasperating getting this 10mm screw in the top part fan shroud. I tried the heating method, that didn’t do anything, but then I used a longer one and wrenched it down really hard, then was able to use the 10mm screw.

Brian M - Reply

Also cracked one of the fan mounting points, but a bit of super glue (and an even lighter touch) worked fine. I agree with earlier comments that a washer might be a wise choice on both of those screws.

Bill Magley - Reply

I had to use a M3x25 screw to help set the nuts in the printed part (with the fan in place), then the M3x18 screws were able to reach the nuts properly.

Paul Bowers - Reply

I had to use a separate small screw to get the nut on the arm in tight so the screw would reach it to the fan mount hole (top one). It’s a very tight fit and the screw will not reach unless you ensure the bolt is all the way in and very tight,

Peter Larsen - Reply

18mm is too short. A 20mm from old MK2 fan worked for one and used a spare 25mm for the other deeper one.

Ray Ackley - Reply

I 2nd Ray’s comment. Was unable to get an 18mm into the “arm” nut. Using a 25mm for the meantime…

Woger Dog - Reply

For the following steps, please prepare:
  • For the following steps, please prepare:

  • P.I.N.D.A. probe (1x)

  • M3x10 screw (1x)

  • M3nS nut (1x)

  • The probe is a sensitive device, please handle it with care during the assembly!

My sensor looks very different… it says “JIMOU Sensor, P/N: IB2T-B0802N-C4B.7/35/PUR”. Hope it works…

Mr Cookie - Reply

Hi Mr Cookie, it will be fine. This is our PINDA probe.

Jakub Dolezal -

My sensor doesn’t look anything like this one, it doesn’t have a label at all. I’m not entirely sure how far down to place the sensor.

Brian M - Reply

Start with the front print fan wire and place it under the cable clip. Gently push the P.I.N.D.A. probe through the mount. Create a loop on the probe wire, then place the wire under the cable clip.
  • Start with the front print fan wire and place it under the cable clip.

  • Gently push the P.I.N.D.A. probe through the mount.

  • Create a loop on the probe wire, then place the wire under the cable clip.

  • Slide the M3nS nut in the slot and tighten the probe SLIGHTLY with the M3x10 screw.

  • The exact position of the P.I.N.D.A. probe will be adjusted later (in Chapter 9, Preflight check), so there is no need to adjust the probe or tighten the screw fully at this point.

Ok here I almost screwed up and inserted the nut in the upper slot. Fortunately I realized in time and managed to take the nut out again. Maybe it’s worth mentioning this in the text? (Be careful to use the correct (lower) slot!). I know that there’s the picture but maybe a small reminder wouldn’t hurt.

Francesco Santini - Reply

I’m finding the PINDA probe exceedingly difficult to mount into the described hole… I’ve attempted several time and it appears the hole is either exactly the same size, or slightly smaller than the probe.

Thomas Hansen - Reply

I found wiggling it side to side helped, but also pushing from other side to help clean out hole, then moving back to correct side.

Rich -

Figured it out. The very thin bridging directly above the washer hole was preventing the “arm” which clamps down on the PINDA probe from moving upward. For me, removing that slight bridging solved my problem.

Thomas Hansen - Reply

THIS! I read this earlier and didn’t understand … now that I inserted the nut and retention screw, I understand - the probe is held in with “jaws” and the two thin bridges at the end of the jaw keeps the jaw from expanding. Without the bridges you could even pry the jaws open a little to help the probe go in.

Why are those bridges there….?

Rich -

I’m assuming we’re not supposed to remove that bridge, right? They clearly designed it to be there, as it would have printed just as well without it.

Evan -

I used the flat screwdriver as a wedge to open it up just enough to be able to slide the probe in quite easily.

Kevin Chua - Reply

Place the Extruder on the Y-carriage as in the first picture. Ensure the correct orientation of the printer, shorter extrusions must be facing towards you. Take the cables from P.I.N.D.A. probe and front print fan, slide it between the lower smooth rod and belt. Take the cables from Extruder motor and left hotend fan, slide it between the lower smooth rod and belt.
  • Place the Extruder on the Y-carriage as in the first picture. Ensure the correct orientation of the printer, shorter extrusions must be facing towards you.

  • Take the cables from P.I.N.D.A. probe and front print fan, slide it between the lower smooth rod and belt.

  • Take the cables from Extruder motor and left hotend fan, slide it between the lower smooth rod and belt.

  • IT IS VERY IMPORTANT to place the cables as shown in the pictures. Please double check your steps.

  • Cables from hotend will be placed under the lowest smooth rod. We will arrange them later.

First I had the printer the wrong way around (front facing me instead of back) and put the cables in from wrong side and had the extruder the wrong way. Would be helpful to add a note in the beginning to check that you have the printer oriented he same way as in he picture (back facing yourself).

Kari Söderholm - Reply

Thanks Kari. Almost did the same thing..

Øyvind Taknæs -

Thank you both for the feedback, description updated ;)

Jakub Dolezal -

Unless I missed a step, need to add how to lower the Y axis to match the picture, assuming rotate both axis until down ‘far enough’ being careful not to go out of level? (I used a ruler to make sure the sides were more or less level)

timcdoc - Reply

For the following step, please prepare: M3x40 screw (1x) M3x30 screw (1x)
  • For the following step, please prepare:

  • M3x40 screw (1x)

  • M3x30 screw (1x)

  • M3x18 screw (1x)

  • Place the Extruder near the X-carriage and check no wire is pinched. There is a slot in the X-carriage for the motor wires, see the picture. Bend the motor cable in it and leave the fan wires straight.

  • Mount the Extruder on the X-carriage using the screws above. Tighten all screws, but not fully. We need to arrange the cables again, this time in the back.

  • Guide the cables through slots (channels) on both sides of the Extruder. On the left side, it is Front Print fan and P.I.N.D.A. probe, on the right side Extruder motor and Left Hotend fan.

  • Ensure again the cables are in the channels and not pinched between printed parts. Now, tighten all screws, equally to prevent issues.

First guide the cables (especially from the extruder), then tighten the screws.

Michal - Reply

Make sure the stepper and hot end fan wires are in the side channel otherwise they will get pinched and damaged when tightening the three screws.

William Dutcher - Reply

+1 William, I had to take mine off and reroute the cable because I missed that.

Austin Hampton - Reply

Guys, thank you for the feedback. Description of the step adjusted.

Jakub Dolezal - Reply

The M3x18 head sunk in far deeper in the part without any added resistance where it should have stopped. A print quality issue?

Bo Gustafsson - Reply

Hi Bo, the M3x18 screw will be fixed by M3nS nut inserted earlier. No resistance along the path (hole) is needed.

Jakub Dolezal -

Jakob, please emphasize placing the extruder stepper motor wires in the channel above the beige fan. I still missed that.

RWReese - Reply

Hi, there is an extra picture for this in step 21. At this step it is too late as the fan is already mounted, if we are talking about the channel above the fan.

Jakub Dolezal -

Agreeing with all the above comments!

My suggestion:

Mount the Extruder on the X-carriage using the screws above. Take especially care that the cables from Extruder and hotend fan are guided in the slot/channel.

Tighten all screws, but not fully. We need to arrange the cables first.

Tom Ludensen Christensen - Reply

Hi Tom,

thanks I will stress out, which cables must be arranged.

Jakub Dolezal -

Additional information needs to be provided for routing the extruder stepper motor cables.  I tucked the cables into the channel above the fan but didn't realize that there was another channel on the x-carriage assembly that the cables needed to be routed through.  I ran the motor cables through the top channel, then around the side of the fan, and into the slot pictured above with the orange arrows.

Corey Dryja - Reply

Corey, had the same cable routing problem as you and I agree there needs to be better instructions.

Thanks

Ezra hawkins -

I definitely agree, the second channel in the x-carriage assembly is on the back side because of the orientation of the printer so many people like you and me have and will miss it. A picture that shows that part of the x-carriage assembly must be addded.

Levent Alpsal -

Hi guys, this step will be expanded to cover the process step-by-step. However, there are some limits, I need to reorganize the steps.

Jakub Dolezal -

thanks Corey, I completely missed that second channel.

There definitely needs to be a picture and some instructions clarifying the guiding of the motor cables!

Adam White - Reply

Really happy that you learned from my folly and didn’t make the same mistake that I did.  This suggestion really needs to be added to the guide because others have been posting pictures of their build with the same cable routing mistake I made.  People are going to start cutting their cables in half.

Corey Dryja -

Yeah, a second picture is absolutely necessary to do it correctly.

Mr Cookie - Reply

Yup and I’ve been seeing people post pictures of their builds with their extruder motor stepper cables routed properly.  This really needs to be added to the guide.

Corey Dryja -

Guys, thanks for the feedback. It is on my to-do list.

Jakub Dolezal -

Don’t forget to place the cables in the channels before you start to screw. This is very important, you can even destroy your cables, if it is not placed properly before placing the screws.

Miroslav Piencak - Reply

Might want to emphasize earlier the location of the extruder fan wire out the back. I guessed (wrong) from the pictures. Maybe a picture of the fan wire in the step where the fan is mounted would be nice.

Joe Pighetti - Reply

I saw the side channel for theextruder motor and fan wires on the mount, but didn’t realise that channel leads to a larger opening on the back of the mount. The wires need to go in there, then through the side channel. That way they don’t get pinched between fan and mount.

Bas - Reply

I did it wrong the first time, too. Perhaps something like, “Note that there is a vertical channel on the X-carriage - ensure that the extruder and fan wires are positioned in this channel and then routed back along the horizontal channel before tightening screws.” (And a front or side view picture would help to clarify that.)

Bill Magley - Reply

This is probably the most confusing step if you don’t realize that there is a cutout and path for the stepper motor cable. This is something I spent a while with on my MK2S build and luckily remembered here. Maybe add a picture of the pocket in the X-carriage so builders get the idea. I suggest adding more detail. What worked for me was to hang the assembly from the 40mm screw, attached loosely. Then route the cables into the slots. Maybe add a warning that if the extruder won’t easily seat against the X-carriage, stop and readjust the cables. When you have it right, it comes together perfectly. When you don’t the temptation is to start to force things and that always ends badly. As with everything else PR does, it’s well engineered but not easy to explain sometimes.

Ira Schonfeld - Reply

Almost broken my cables, since I did not realized how to route the extruder cable from the first channel to this one…

Lyubomir - Reply

If you can‘t reach the top m3x40 hole you need to lower the X gantry.

Per Hansen - Reply

Lowering should have been a much earlier step, as if it’s too high you’re already balancing the assembly in one hand.

Evan -

Thanks, I was totally confused here. Simple, once you point it out.

Shelley Dorbin -

Cable placement should go first on the list. I almost messed things up too. The M3x18 screw can go way too deep, it should be mentioned not to do that.

Zsolt van den Mar - Reply

Guys,

thank you for the feedback, step will be updated.

(@mirecxp, @pighetti, @bas, @bmags, @irasch, @lpetrov, @vandenmar)

Jakub Dolezal - Reply

ARGH - could you use something other than two colors that look like eachother? Symbols or something would be helpful for those of us who are color challenged …

Peter Larsen - Reply

Is the one circled in Green really supposed to be M3x30? Mine sticks out too far. The M3x18 seems to fit here. It could be that the nut on the other side got turned a bit and is the reason I can’t fit the M3x30 in there, but I want to verify before I have to pull the whole thing apart…

Brien King - Reply

Hi Brien, yes it should be M3x30, make sure there is no obstacle in the hole. Use for example and Allen key.

Jakub Dolezal -

Locate the cable for filament sensor in the package. There are two types of the connectors on the cable:
  • Locate the cable for filament sensor in the package.

  • There are two types of the connectors on the cable:

  • The 4-pin connector for the sensor (used now)

  • The 5-pin connector for the EINSY board (used later)

Are these backwards? Einsy board can’t accept a 5 pin plug?

Cameron Lamont - Reply

Hi Cameron, 4 pin connector (marked green) goes to the sensor and the 5 pin connector (marked orange) goes to EINSY. In case you can't fit it, you must be using different port on the EINSY board.

Jakub Dolezal -

I had the same problem. Since the picture doesn’t label the lines (that comes in step 32) you think the PINDA probe is where the filament sensor goes. I just took it all apart - and realize that the picture isn’t a good guide on section 8. Suggest starting with a complete map of all plugs and some help identifying the cables.

Peter Larsen - Reply

Use the cable from the previous step and connect it carefully to the filament sensor. Note the connector has two different sides. The side with safety pin must be on the left (white wire is facing up and red down). Gently rotate the cable (clockwise) to create a small loop, see the second picture.
  • Use the cable from the previous step and connect it carefully to the filament sensor.

  • Note the connector has two different sides. The side with safety pin must be on the left (white wire is facing up and red down).

  • Gently rotate the cable (clockwise) to create a small loop, see the second picture.

  • Push the cable through the opening on the X-carriage.

rotate the cable to the loop because a straight wire directly ouf of the plug will collide with the frame or spool holder on top when reaching 180mm or more.

maybe, if you’r using a custom spool holder, the spool holder itself won’t work any longer on a MK3

Heiko Schultz - Reply

Good point, this should be added to the step to explain why you need to loop the cable as people might not bother.

Robert Hunt -

As silly as this sounds, now is the perfect time to notate that the bottom bearing needs to be properly seated, mine was loose to the right of the extruder mount at this point as it was not attached in any way (so still on the rod, not seated in the printed mount) and I didn’t catch it until self=test calibration on the X-Axis failed as the bearing was impeding travel…. it was a major pain to go back and fix it.

Benjamin Curto - Reply

Is it normal that my filament sensor wiggles a bit in place?

Andreas Sjolund - Reply

Hi Andreas, it is not ok. The sensor must be secured in place. Please see Step 8.

Jakub Dolezal -

Be careful that your “small loop” is not too big vertically! Despite the fact that I attempted to check to make sure the wire did not interfere with the horizontal travel on the X axis, the loop I made was a little taller than the connector, and a little wider than the bearing. This made it collide with the spool holder, which of course one doesn’t install and thus find out until the VERY LAST STEP OF THE ENTIRE BUILD! Be sure to look at the third picture of this step and make sure your final loop is “tight enough”. It should not extend beyond the back of the rod bearing, nor should it go higher than top of the connector.

Joel Kozikowski - Reply

Hi Joel, thanks for sharing your experience with the build. The loop should be really small as in the picture. Just few mm.

Jakub Dolezal -

Does the “safety pin” actually click into place to lock it in? I was expecting it to do that, but even with a good amount of pressure it doesn’t click for me. It seems stable and doesn’t look like it will come loose, but it worries me.

Bill Magley - Reply

Nope……………… .

John Hawkins -

Starting mid of February 2018, there will be only one 50cm NYLON filament included. There are two NYLON filaments included in the kit with lengths 50 and 30 cm. Both have Ø 3 mm. For this step please use the longer one and DON'T TRIM any of them! Using the pliers cut one end of the filament to create a tip.
  • Starting mid of February 2018, there will be only one 50cm NYLON filament included.

  • There are two NYLON filaments included in the kit with lengths 50 and 30 cm. Both have Ø 3 mm. For this step please use the longer one and DON'T TRIM any of them!

  • Using the pliers cut one end of the filament to create a tip.

  • Check the tip is similar to the third picture.

its is better to cut out with a cutter

printminion - Reply

We are using the tools, which are included in the kit, but if you have some more appropriate tool at your disposal, use it ;)

Jakub Dolezal -

The included pliers/cutter just squished the filament without breaking it. I had to use a different tool.

Neal Tibrewala - Reply

Hi Neal, it is possible to do it with included pliers (picture above is the proof), in case you have a better tool, please use it :)

Jakub Dolezal -

You should write the line with “Starting mid of February 2018, there will be only one 50cm NYLON filament included.” on the top. I searched all my boxes twice because i searched for the second nylon filament mentioned in the first sentence :(

Sebastian Moder - Reply

Agreed. Just added 15 minutes to the build time and 100 swear words to my tab.

Jeremy -

I spent a good 15 minutes looking around for the “second” nylon filament. Absolutely agree

Woger Dog -

Mine did not ship with ANY nylon fillament

Eric Harten - Reply

Same with me - no nylon filament in the package. Is it OK to just go ahead without it?

Mark Chu-Carroll -

Guys (@hartene, @markcc), please check the package once more, the nylon filament could be stuck at the bottom of the box. If you can’t find it, please contact our support at info@prusa3d.com

Jakub Dolezal -

It would be easier to understand this step if the purpose of the filament is explained, that its purpose is to support the cables and not to be used for printing. I used the printed guide, hard to understand this step, why insert filament between the cables? Very hard to se the hole, with the X-carriage back mounted according to the printed guide.

Hans Palm - Reply

Locate the hole for the NYLON filament. Using the smallest Allen key ensure there are no obstacles inside. Using the pliers insert the NYLON filament in the slot. Hold the extruder with your second hand. BE EXTREMELY CAREFUL as the pliers tends to slide and you can easily damage the wires!!!
  • Locate the hole for the NYLON filament. Using the smallest Allen key ensure there are no obstacles inside.

  • Using the pliers insert the NYLON filament in the slot. Hold the extruder with your second hand.

  • BE EXTREMELY CAREFUL as the pliers tends to slide and you can easily damage the wires!!!

  • To check if the filament is seated properly, gently pull it with your hand. The X-axis should bend a little, but the filament must remain in the slot.

  • If you have issues, try to adjust the tip on the filament.

It would be helpful if we knew what kind of connection is happening inside … so we know how to adjust the tip.

Rich - Reply

Hi Rich, the connection type is mostly friction. The tip on the filament is used to enter the hole easily.

Jakub Dolezal -

Please explain why this nylon filament is only visible on step 30 ?

I can’t see it anymore on steps 36 &37 pictures.

Even on video build found on YouTube, this step seems missing.

What the utility of this piece ?

Stephan - Reply

Hi Stephan, the nylon is not visible just because it is hidden under other cables from the Extruder, but it is still there. Nylon is much stiffer (rigid) compared to the other cables, it will hold the entire bundle up during prints and also retakes most of the load introduced by the moving Extruder.

Jakub Dolezal -

I’m unable to insert the 50cm NYLON filament into this slot.  I cut the NYLON at an angle as requested in the previous step, though when I try to push it through the slot, the pliers end up scratching the NYLON instead of being inserted.  I tried to cut the NYLON angle another time, with the same results.  Is the NYLON supposed to go all the way through and come out the left side, as the picture shows?

Richard January - Reply

“insert the NYLON filament in the slot” - about how far? Like Richard above, I find it very difficult to insert, even with a perfect tip cut.

Gerry P - Reply

Hi Richard and Gerry (@rjanuary, @gerrypez),

in case you can't insert the nylon filament in, please try decreasing the diameter of the nylon using a knife (make the tip slimmer). You should insert the filament few millimetres in, no exact value is given, but I will discuss this with the devs.

Jakub Dolezal - Reply

Could an approximate length of filament that will be pushed into the extruder assembly be documented? I was only able to get about 1cm to go in (with laborous pushing & twisting) and I don’t know if that is sufficient to support the wiring bundle over time.

Jeremy - Reply

For me, this was definitely the most frustrating part of the entire build. As I look at it, it seems to me that the insertion of the nylon is really just to have it be held in place while you get the rest of the cabling under control coming out the back of the extruder assembly. Once past Step 39 the zip ties will assist with keeping the nylon in place. So yes, only a couple millimetres of insertion is enough here.

But, that is a tough couple of millimetres!

My suggestion would be to adjust the hole to be a wider diameter with a hook ridge around the circumference 10mm into the hole. Then with a notch on the end of nylon it would simply slide in and lock into place, holding it there while the rest is done.

SteveP - Reply

I twist the nylon filament in by hand instead of push it in. Way easy and secure too.

W Lai - Reply

Small vice grips are your friend on this step. Tried it with the supplied tools but that was going nowhere.

Trevor Friesen - Reply

For the following steps, please prepare:
  • For the following steps, please prepare:

  • X-carriage-back (1x)

  • Cable-holder (1x)

  • M3n nut (1x)

  • M3x10 screw (1x)

  • The M3x10 screw will be used temporarily, use one from the spare bag.

  • M3x40 screw (1x)

Add Comment

Insert the M3x10 screw in the X-carriage-back. Tighten it completely. Rotate the printed part and insert the M3n nut. Tighten the M3x10 screw until the nut slides in the printed part. Note the shape of the cutout for the nut, you might need to adjust (rotate) the nut.
  • Insert the M3x10 screw in the X-carriage-back. Tighten it completely.

  • Rotate the printed part and insert the M3n nut.

  • Tighten the M3x10 screw until the nut slides in the printed part. Note the shape of the cutout for the nut, you might need to adjust (rotate) the nut.

  • Remove the M3x10 screw and place it back in the spare bag.

Stuck here. Nuts keep falling off. Cannot sit tightly on printed part

Cell99@Mike - Reply

Doesn’t really matter, just move onto the next few steps where the cable-holder is attached, it will keep the nut in place.

Robert Hunt - Reply

The bag of spare fasteners was a good idea. At this step the nut seized on the M3x10 screw before the nut bottomed. It was impossible to get a good grip of the nut since it had sunk enough in the plastic to make it ungrippable. The head of the screw had to be drilled off so the nut could be removed. Luckily the new nut went in well and did not seem to spin in the now by the seized nut reamed hole.

Bo Gustafsson - Reply

Managed to get the nut to sit. I used a plier to twist the nuts as far in as possible and then I screw the m3 screw from the other side to pull the nut in. If the nut is dotted properly the next 2 step is easier.

Cell99@Mike - Reply

I had the same problem Bo encountered. I believe this step should be removed as the nut will be retained during, what is currently, step 30. I will also have to cut the bolt head off and I have not determine if I will need to reprint the part yet. Maybe in the future these components should be reviewed to relocate the retainer nut so that it is not so close to the bottom x bearing housing. I may reprint this piece with the wire harness bolt moved down 1-2mm.

Regards,

Jeff Underly - Reply

On my X-carriage-back (version A9) the “MK3 sign” was very shallow, almost invisible. After tightening the M3x10 screw and successfully pulling the M3n nut into its hex-shaped hole I was concerned the nut protruded too far and would be in the way of the bottom x bearing. I removed the M3x10 screw and did a quick test fit of the X-carriage-back against the bearing. The nut was definitely protruding about 1.5 mm too far! Using the M3x10 screw I fixed this by repeatedly and carefully tightening and loosening the screw to gradually pull the M3n nut farther into its hole until the nut was flush with the plastic. Warning: a protruding nut could damage the bottom x bearing when the X-carriage-back is mounted in Step 35.

Bill Waring - Reply

Prepare the M3x40 screw and cable-holder from the previous step. Tighten the screw all the way through the printed part.
  • Prepare the M3x40 screw and cable-holder from the previous step.

  • Tighten the screw all the way through the printed part.

  • Note there is a recess (slot) for the screw's head on one side of the printed part.

You can not tighten it yet. It just slides in.

Michael Stegen - Reply

Hi Michael, you should be able to slide/push the screw through the part, but sometimes Allen key is needed.

Jakub Dolezal -

There are a number of places in this manual where the word “tighten” or “tighten completely” may not be the best choice of words. In this case, “fully insert” would be better. Likewise, in Step 28 “tighten completely” is not possible as there are no threads to allow the screw to become tight. Perhaps “thread the screw completely through…” is better. On the Y axis belt assembly, I cracked my belt holder following the instructions to “tighten completely” and put a little too much force not yet having a feel for how brittle the plastic is. I think Michael is just pointing out that the language could use some improvement on this step (and maybe others).

Ryan Sealy - Reply

It would be more correct to say recess instead of slot in “Note there is a slot for the screw's head on one side of the printed part.”

Aaron Pool - Reply

Hi Aaron, thanks for the suggestion, description updated.

Jakub Dolezal -

Place the X-carriage-back as in the picture. You must see the MK3 sign. Tighten the X-carriage-back and the cable-holder together. Check the "u-shaped" slot is aligned properly on both parts.
  • Place the X-carriage-back as in the picture. You must see the MK3 sign.

  • Tighten the X-carriage-back and the cable-holder together.

  • Check the "u-shaped" slot is aligned properly on both parts.

Printed part is 3mm too long. The m3x40 screw needs 6mm to secure to the trapped nut, and it only has 3mm overhang once fully inserted into the cable holder.

Bill Connelly - Reply

Hi Billy, are you sure the screw was fully inserted and nothing was blocking it?

Jakub Dolezal -

Same problem with mine. Could hardly grab the threads of the nut.

Tim -

Your part must have had better printing, there’s no discernible MK3 marking on mine

Steve Worcester - Reply

Hi Steve, the parts were taken from our printing farm. It might be different part revision.

Jakub Dolezal -

I shoved the nut in twice, both times screwing it in. Then rescrewed the long screw, and it didn’t go through properly. I think the screw needs to be longer, or like Bill said, the part is too long/not deep enough for the screw.

Mr Cookie - Reply

Hi Mr Cookie,

did you follow the instructions in Step 28? If the nut isn't deep enough you won't be able to reach it with the screw.

Jakub Dolezal -

I had top go back and redo step 28. I’d been too gentle for fear of breaking something. Once the nut was properly sunken in I was able to get the screw in place.

H4irBear - Reply

The “MK3” isn’t legible on mine, either - using a flashlight to light it from an oblique angle, I can see what looks like it *might* say MK3, but I couldn’t see it under ordinary room light. Maybe just say, “Smooth side up”?

Bill Magley - Reply

No Mk3 on mine

Jonathan Butters - Reply

Yup, looks like the latest revision does not have the “MK3” marking.

Evan -

Push the cables from the Extruder THROUGH the X-carriage-back. Start with Extruder motor and the Left hotend fan. In the next step add the Front print fan and P.I.N.D.A. probe cables. Cables from hotend and filament sensor are NOT GOING through the X-carriage-back!
  • Push the cables from the Extruder THROUGH the X-carriage-back. Start with Extruder motor and the Left hotend fan.

  • In the next step add the Front print fan and P.I.N.D.A. probe cables.

  • Cables from hotend and filament sensor are NOT GOING through the X-carriage-back!

  • Carefully insert the nylon filament and then slide the X-carriage-back towards the X-axis.

Check to make sure the nylon fits now before putting the cover on. My hole was too small.

Paul Betz - Reply

I had to go back to this step to add the nylon! I can highly recommend doing it NOW! Much less chance to damage the wires!

Christoph Stahl - Reply

Agreed - place filament now and be patient and careful while tightening in step 35.

David Beach -

I agree that the nylon needs to be inserted now. I had to undo everything from step 38 back to this one to get the nylon in.

Ken Ondo - Reply

Guys (@stahlfabrik, @kjondo), the decision to put the NYLON filament later on is based on our experience during internal tests. Many users managed to pull the NYLON filament out during the X-carriage-back assembly, but thanks for the feedback. We will consider some changes.

Jakub Dolezal - Reply

my printed manual had several steps in between this and the last one, about the cable and where (and how) to plug it in. They seem to be missing online, would have been useful for knowing if it was plugged in the right way

David Kaufmann - Reply

Hi David, there was an updated to this chapter, which included different steps arrangement. Nothing is missing, which cable do you have in mind?

Jakub Dolezal -

Before pressing the X-carriage-back against the X-axis, place the filament sensor cable through the slot. See both pictures. Check the cables are not pinched between the X-carriage-back and the X-axis!!!
  • Before pressing the X-carriage-back against the X-axis, place the filament sensor cable through the slot. See both pictures.

  • Check the cables are not pinched between the X-carriage-back and the X-axis!!!

Add Comment

Using five M3x10 screws tighten the parts together in following order: Start in the middle and ensure proper alignment.
  • Using five M3x10 screws tighten the parts together in following order:

  • Start in the middle and ensure proper alignment.

  • Continue in the corners, tighten all screws equally.

  • After the tightening is done, push the filament sensor cable in the slot along X-carriage-back, join the remaining cables.

I had to losen the 2 top skews or els my length calibration wouldn’t finish.

Ian Warendorf - Reply

Hi Ian, can you please describe your issue? You can attach pictures as well (http://manual.prusa3d.com/Answers). Thanks

Jakub Dolezal -

I also found that self test will give X axis error when the five screws are tightened to much. Just tighten the screws until the seams between the printed parts close. All five, not just the top two.

Christoph Stahl -

Go to step 37/38 (Inserting the NYLON filament) and check if you do not want to do it now.

Michal - Reply

The (2) M310 screws were too short to catch the nuts for the top two points, I used (2) M318 from the E-axis bag that (as far as I can tell) aren’t being used anywhere else. They fit, they work.

Benjamin Curto - Reply

Hi Benjamin, I strongly advise against using different lengths of the screws. The design is tested several times before being released. Are you sure both printed parts are seated properly and there is no gap between them, which may result in “need” of longer screws?

Jakub Dolezal -

Confirmed, had to loosen screws to succeed in X-axis calibration, should be noted to tighten (all five) just until seams close then stop.

Benjamin Curto - Reply

Hi Benjamin, if the parts are seated properly, you can tighten them without affecting the X-axis calibration. What issue was causing your printer to fail X-axis calibration?

Jakub Dolezal -

I also had the same problem with the top 2 screws not screwing in all the way. The printed parts appear to be seated properly. I adjusted the middle screw and re-aligned the printed parts. The top 2 screws still had trouble catching the nuts and I had to apply a bit of force to get the screws to catch.

Alex Wilkie - Reply

Same here. My problem was that the nut for the cableholder (inside) was still standing out a little bit. I thightend the cableholder scre more so that the nut was more pulled in. After that, the back was fitting well.

Martin - Reply

If I tighten all the screws for a flush fit, there us significant binding on the rails. I have to back the screws off until they are almost loose. The binding causes the X-axis calibration to fail.

Tim Deagan - Reply

The heads to the zip ties around the bushings were in the wrong position and interfered with attaching this piece. I ended up pulling the center screw through the back piece before I realized the issue.

The back is still held securely by the 4 screws on the corners. Should I stop the build and get a replacement, or is it ok to continue on and print out a replacement as soon as the printer is functional?

Adam Kawula - Reply

Hi Adam, if the X-carriage-back is held in place by 4x M3 screws, it is ok to finish the assembly. However, reprint the damaged parts as soon as possible and assemble the printer according to the manual.

Jakub Dolezal -

Jakub, you may wish to consider moving the insertion of the 5 square nuts M3nS from Step 3.11 to the beginning of this Step 5.35. These nuts are used only. Otherwise they will probably fall out during many steps before getting here (it happened to me with the central and one of the lower nuts, they dropped out unnoticed and I had a prolonged moment of panic when I discovered my two screws have no nuts to grab on). This can quickly become a big problem for the unaware and inexperienced first time MK3 builder. These 5 nuts are very easy to insert at the beginning of Step 5.35, just swing out the X-carriage latched on at the top by two zip-ties, slide temporarily the single linear bearing away, and you have full access to the nut slots. Anyhow, these 5 nuts are required only here, far, far away from Step 3.11…

Alan Rusyak - Reply

Minor nit: as in the rest of the manual, pictures of the 5 m3x10 bolts below one with green arrow four with orange.

timcdoc - Reply

I had trouble getting the center bolt started, starting the other 4, then using a longer bolt in the center just to start the threading solved the problem. probably just a bit of plastic fluff. I did not have to snug the longer bolt.

timcdoc - Reply

Wrap the spiral wrap (the largest and the longest one) around the cables and the nylon filament. Start with cables from the upper part, after 3-4 turns (not more!) slide the wrap on the cable-holder. If possible, press the wrap slightly in the X-carriage-back.
  • Wrap the spiral wrap (the largest and the longest one) around the cables and the nylon filament.

  • Start with cables from the upper part, after 3-4 turns (not more!) slide the wrap on the cable-holder. If possible, press the wrap slightly in the X-carriage-back.

  • Don't wrap the entire cable bundle now, we will get to it later.

Jakub, it might be good to mention here that only 3-4 initial wraps should be done, as later the hotend cables need to be added. As it is, in my eagerness I wrapped the whole length of the spiral wrap (silly me!), only to have to undo it later (Step 42) to add the hotend cables…

Alan Rusyak - Reply

Hi Alan, step description updated. Follow the manual (pictures and text) and you will be fine :)

Jakub Dolezal -

My kit didn’t have a long piece of spiral wrap in it. Instead there was a length of a sort of curled up plastic sheathing. ???

Bill Wightman - Reply

Edit to my previous comment: My kit DID come with the textile sleeve, which was used to wrap the wires from the heat bed to the PSU. I didn’t see any spiral wrap long enough to handle the wiring from hotend to PSU…

Bill Wightman - Reply

Hi Bill, in case you are missing the spiral wrap, which is used for the extruder cable bundle, please contact our support using email info@prusa3d.com or via live chat at shop.prusa3d.com

Jakub Dolezal -

My center screw is all the way in, but spinning freely, not biting on anything. I think I may have stripped something. Is this going to be an issue? Everything seems solid despite that.

Ben Fillmore - Reply

Dang. This comment was supposed to be on the previous step.

Ben Fillmore -

Hi Ben, there should be nut in the “middle” of the X-carriage to which this screw connects, remove the X-carriage-back and have look. Anyway, as long as the other four screws work, you should be fine. You can also reprint the X-carriage in case the slot for the nut is damaged and allows the nut to rotate.

Jakub Dolezal -

Could you add a note or ProTip that users will complete the wrapping in step 41? Might save some time and frustration; seems logical to finish wrapping in step 39 and some folks dont follow directions explicitly. Just a thought.

Jeremy - Reply

Hi Jeremy, note added to all the steps, where spiral wrap is used. Thanks for your suggestion ;)

Jakub Dolezal -

Use three zip ties and push them through the lower slots on the cable-holder Check for the last time both the wrap and cables are seated properly.
  • Use three zip ties and push them through the lower slots on the cable-holder

  • Check for the last time both the wrap and cables are seated properly.

  • PAY GREAT ATTENTION to the final position of the zip ties. If you don't follow the manual, you will have issues during prints!

  • Tighten first zip tie on the side of the cable-holder and cut the zip tie as close as possible to the printed part.

  • Tighten second and third zip tie on the top, but note they both must be slightly to the left. Cut the zip ties as close as possible to the spiral wrap.

  • Don't wrap the entire cable bundle now, we will get to it later.

With the cable ties in this exact position, the top square part of the ties was bumping into the PSU frame, preventing the X axis from moving all the way to the right, and resulting in a self test X axis failure. I had to rotate the ties so the square part is positioned directly on top of the cable bundle instead of slightly left.

Jason Livingston - Reply

I confirm, that’s the case with the middle zip tie. The outers don’t cause any problems.

https://tinyurl.com/y9bjfvg2

Heiko Schultz -

Hi Jason, can you please post pictures of your setup? We've tested the zip tie layout several times to ensure, it works.

Heiko (@predatorjr) you zip ties are not aligned as described in the manual, please recheck this section.

Jakub Dolezal -

I had a similar problem. I had to move the zip tie closest to the extruder to avoid it hitting the frame and causing the self test to fail. It was exactly as the images (but the zip tie was trimmed flush on mine, which should be the best case for clearance). To fix it, I did as Jason suggested and moved the square part of the zip tie to the top of the bundle.

Steven Underwood -

I had exactly the same issue with the zip tie closest to the extruder. Moving all the heads to the top solved the x-axis calibration error.

Orne Brocaar -

I can confirm I had the same issue as Steven. Moving all zip ties to the top fixed the issue.

Paul Betz - Reply

Both of my MK3s had the same issue as well. All 3 zip ties have to be in the top position for the X-axis to work properly

Ezra Scott - Reply

I tried following the directions but experienced an x fail so I listened to the comments and now it works properly.

Kyle Campbell - Reply

Same here, X text failed. Orange arrow, innermost zip tie hitting frame when placed as shown above. With all zip tie ratchets on top it works just fine.

J Allen - Reply

Guys, thank you very much for the feedback, we will rerun our tests again and make adjustments to the manual.

Jakub Dolezal - Reply

Same here. Had X-axis failures until I moved the zip tie heads on top.

The description is very specific in getting the closest zip tie to be on the side otherwise “you will have issues during prints! “. I couldn’t figure out what these could be. Could you elaborate?

LaurentR - Reply

Hi Laurent, for certain geometry of spool holder the “closest” zip tie can cause crashing of the Extruder in the top position, that is we advise to move it on side and cut the as much as possible of the overhanging part.

Jakub Dolezal -

Same issue with zip ties here, solved by rotating all heads to top or bottom of wire bundle.

Bruce Moore - Reply

Well, what should I do then? Follow the pictures or comments? Has anyone ended up with a functioning system following the manual?

I-Man - Reply

Like the other builders I found that I needed to rotate the zip ties to the RIGHT so that they did not protrude over the lefthand side of the cable support assembly. Doing this cured my X axis failure found on running the Wizard.

Phil Higgins - Reply

Use two zip ties and push them through the upper slots on the cable-holder. ATTENTION! Before tightening the zip ties add the cables from the hotend. Once the hotend cables are included, tighten the zip ties and cut remaining parts.
  • Use two zip ties and push them through the upper slots on the cable-holder.

  • ATTENTION! Before tightening the zip ties add the cables from the hotend.

  • Once the hotend cables are included, tighten the zip ties and cut remaining parts.

  • Don't wrap the entire cable bundle now, we will get to it later.

Be sure to place the clamp part of the zip ties at the bottom of the assembly, as shown in the picture. If the clamp is on the side, it will interfere with the full range of motion of the extruder in X and Z.

Jay Sinnett - Reply

Make one more turn of the spiral wrap, then add the cables from the hotend. Wrap the whole cable bundle.
  • Make one more turn of the spiral wrap, then add the cables from the hotend.

  • Wrap the whole cable bundle.

This cable management is so clean and wonderful! I always struggled to get the mk2s as clean as I wanted it to be, for me this is a very nice improvement (as well as so many other “small" improvements in addition to the new features).

Steven Underwood - Reply

Hi Steven, I'm glad you appreciate the update to the cable management ;)

Jakub Dolezal -

For the following steps, please prepare:
  • For the following steps, please prepare:

  • Idler-plug (1x)

  • Filament-sensor-cover (1x)

  • PTFE tube (1x)

  • M3x10 screw (2x)

Where am I supposed to find that PFTE tube cut?

Alex Tutusaus - Reply

in the bag “5. E-axis”, it is together with nuts and bolts

Jakub Dolezal -

I believe my printer kit was shipped without this Idler-plug. It was not in the bag labelled ‘E-axis’ where it says it should be. Is this part something I can print later once the printer is operating?

Patrick Lynn - Reply

Hi Patrick, the idler plug can be printed later on. Download the MK3 bundle from here: https://www.prusa3d.com/prusa-i3-printab...

Jakub Dolezal -

Locate the largest circular opening for the PTFE tube on the top of the Extruder. Push the PTFE tube in. Majority of the tube's length will stick out.
  • Locate the largest circular opening for the PTFE tube on the top of the Extruder.

  • Push the PTFE tube in. Majority of the tube's length will stick out.

  • In case the PTFE does not hold properly in the hole, you can assembly it to the cover first, BUT MAKE SURE the is no obstacle in the hole as you can easily deform the tube while placing as a part of the cover.

If you have clumsy hands like me go ahead and put the PTFE tube in into the filament cover. It will stay in place that way when your putting the cover on instead of flying across the room when your hands slip.

Paul Betz - Reply

Hi Paul, the PTFE tube is made from rather soft material. We suggest our way of assembly to prevent damage to the tube in case there is an obstacle in the hole. If you use cover, you can introduce much higher force and deform the tube.

Jakub Dolezal -

I reached the same conclusion as Paul, possibly for a different reason. The PTFE tube did not fit ‘firmly’ in the hole in top of the extruder, it just wobbled about loose. It looks if I tried ‘pushing’ the tube in, expecting to find a firmer fit, I might have tried pushing it hard against the side of the imaging IC on the filament sensor which seems risky.

For my parts, as far as I can tell there wasn’t an obstacle in the hole, much the opposite, it was too loose, and I couldn’t ‘push’ the tube into the extruder, rather just ‘rest’ it in there. I pushed it into the cover instead to get things to align, and the cover screw down without a problem.

I agree this was quite possibly a bad idea as in trying to debug what happened I find I cannot pull the tube back out of the cover, suggesting it is quite tight. I’ll see what happens, and don’t have specific suggestions for others following the instructions.

Kenneth Albanowski - Reply

I did the same as Paul and Kenneth and found this a better way than placing the PFTE in the hole first (it was wobbly and didn’t go in too much). I took it apart again to check for any damage and didn’t see any so I believe it’s a safe bet in case you can’t for some reason do it as per manual instructions.

Florian Ford - Reply

This step confused me. I was determined to try to do this the recommended way and placed the PTFE tube in the Extruder but wasn’t totally sure of its placement. I fumbled around and the placement is definitely not obvious until you place the cover on. I almost thought I had a blockage and was ready to drill it out until I test fitted the cover. FYI the correct placement of the tube is in the large hole as shown (not next to the round hole where the thing looks like it may have room to go down further. Nope. It sits in the (slightly too large hole) about 3.8 mm deep and rests on a tiny little shelf which to me was so small that it looked like a blockage from printing the part. So yeah, go with Paul and Kenneth or perhaps modify the part or description please!

Andreas Sjolund - Reply

Hi Andreas, step description updated. Anyway we’ve tried several approaches and it is easy to deform the tube if you press it down as a part of the cover. You have to be very careful.

Jakub Dolezal -

I used a 3” piece of 1.75mm filament to align and make sure there was no bind when tightening down the top.

Frank De Abreu - Reply

Carefully slide the filament cover on the PTFE tube. Using two M3x10 screws mount the cover.
  • Carefully slide the filament cover on the PTFE tube.

  • Using two M3x10 screws mount the cover.

The button right screw does not fully tighten. It does not stop rotating but it hold the cover in place and does not rotate freely. I’be tried to back trace the installation steps in the manual and could'nt find where the insrucation of the nut is? Is it missing?

יוסי שלי - Reply

Hi, there isn’t any nut hidden in the Extruder body. Both screws should “bore” in the printed part of the Extruder, this is enough to keep the m in place. Please check the cover isn’t able to move and let me know ;)

Jakub Dolezal -

Suggestion - *any* time a screw is going to be “self-tapping” into plastic, please note something in the instructions like, “This screw threads into plastic - tighten until firm but do not over-tighten or you may strip it!” Since nuts are used to capture screws in so many places, it’s very easy to be too strong on a plastic-threaded part.

Bill Magley - Reply

I agree with Bill. The self tapping screws should be documented.

phr0ze -

Locate the part, where the idler is cut out (M3 screw is visible). Assemble the idler-plug and ensure it fits properly. Otherwise, it might fall down during the print.
  • Locate the part, where the idler is cut out (M3 screw is visible).

  • Assemble the idler-plug and ensure it fits properly. Otherwise, it might fall down during the print.

Can someone explain the purpose of this plug? Is it just for looks or does it serve a function?

Paul Betz - Reply

Hi Paul, the plug prevents dust and other particles from the reaching the sensor.

Jakub Dolezal -

I found myself asking this same question.

Joe

jperch - Reply

Hi Joe, the plug protects the sensor. See my comment above.

Jakub Dolezal -

If the cut out on the idler must be closed to protect the sensor from dust, then why is there a cut out in the first place?

Levent Alpsal - Reply

^^^ good question!

Lyubomir -

I’m not certain, but I think it provides a port so you can use an air duster to blow out any dust that might get on the sensor.

Bill Magley -

A very good question!

David -

I think, that this cut-out is to have a possible check on the sensor.

Leo -

Hi Levent, you need to be able to check the sensor visually.

Jakub Dolezal -

For the following step, please prepare: Fan-nozzle (1x) M3x10 screw (1x)
  • For the following step, please prepare:

  • Fan-nozzle (1x)

  • M3x10 screw (1x)

  • Carefully slide the X-axis up so you have access to the lower part of the Extruder.

  • Release slightly both screws on the front print fan.

  • Assemble the fan-nozzle and tighten all three screws.

  • In case you are missing M3x10 screw, please use one from the spare bag.

I do not have M3x10, I have two M3x18 and one M3x30. The package contained only 9 pieces of M3x10.

Michal - Reply

Same, but I had an extra from a previous step so I didn't have to dip into the spare bag.

Steven Underwood -

Same with me too. I had two extras from a previous step. I keep winding up with extra screws or missing some so I keep second guessing myself thinking I screwed up somewhere.

Paul Betz - Reply

Same here. 2 m3x18, 1 m3x30, no m3x10. Stole a spare from previous step.

Paul Meyer - Reply

Same here. Spent a fair amount of time retracing my prior steps to see if I’d made a mistake.

Brandon Oprendek - Reply

Step description updated, in case you are missing screw to mount the fan-nozzle, please use the spare bag. I'm sorry for the issues.

Jakub Dolezal - Reply

What was the purpose of loosening the print fan ? For me the part seems to fit correctly regardless.

Chris Pardy - Reply

Hi Chris, to align nozzle and fan it is better to have them both loose.

Jakub Dolezal -

missing M3x10 also.

Josh Miller - Reply

Step 35 I’m fairly sure was supposed to be (2) M3x18 for the top two points (not M3x10), that’s what I used and now I have this M3x10 free for this step.

Benjamin Curto - Reply

Hi Benjamin, screw lengths have been checked several times, they are all correct. Some early MK3 kits might be missing this M3x10 screw, but you can use one from spare bag.

Jakub Dolezal -

Missing here too

Alistair - Reply

No 10mm screw left but, as mentioned before, there were a couple left from previous steps that seemingly had extra. For me the fan duct went on with absolutely no effort and screwed in right away. I checked it from all angles, it went on as it should have so no blower fan touching for this step..

Florian Ford - Reply

When I slide up the X axis its much easier to slide up the right side compared to the left (where it feels much safer to turn the screw with my fingers since its so difficult to make the motor turn. Is this normal?

Andreas Sjolund - Reply

Hi Andreas, the amount of force needed for turning left and right side should be the same. If you observe the printer has issues during prints to move the axis up, please contact our support.

Jakub Dolezal -

Why does it say “HOT!2”? I get the “HOT!” part, but why the 2?

Bas - Reply

That is a mystery and only Josef Prusa himself knows the answer :)

Jakub Dolezal -

My plastic fan nozzle was not alligned nicely, so I used a bit more force on the screw and then it broke. Fortunately, printing goes fine without it.

Edwin Martin - Reply

I had the M3x10, but I also wound up with an extra M3x30 and two M3x18 screws. I’m pretty careful about not missing steps, and I don’t see anything obvious, so I’m going to assume they are just more extras for the spares bag!

Bill Magley - Reply

The bottom entry to the fan housing split as I was re tightening it. Didn’t seem like it increased in resistance at all while I was screwing it it, just started splitting down the side.

Yeah the opening was large enough to allow the screw head to enter and split it. I’m going to try a small washer to get some tension there.

Evan - Reply

Are we there yet? Almost! You've just finished the hardest part of the assembly. Awesome job!
  • Are we there yet? Almost! You've just finished the hardest part of the assembly. Awesome job!

  • Check the final look, compare it to the picture.

  • Checked everything? Let's move to: 6. LCD assembly

Why no gummy bear?

David Naoum - Reply

I assumed gummy bears to be already eaten :)

Jakub Dolezal -

The hardest part and we don’t even get one gummy bear? That felt like it was worth 3 gummy bears

Josh Miller - Reply

Josh if you have some left, then definitely treat yourself ;)

Jakub Dolezal -

You’ll be 3D printing gummy bears in no time.

Andreas Sjolund -

I was also sad to not see the gummy bear instruction in the manual. :(

Paul Bowers -

Man this was sooo complicated and definitely hardest so far… I am kinda scared about reaching to different parts should the need arise… like if we want to take the belt away, or if it’s still too loose (skipping steos), etc etc … it would be such daunting to take it all apart. I believe at least access to the belt’s insertion onto the X Carriage should have been granted by design.

Florian Ford - Reply

Hi Florian, the Extruder is the hardest part indeed and we are listening to your feedback, so currently testing new parts for easier assembly and maintenance ;)

Jakub Dolezal -

Cannot suggest a time. However Cook me 1:45

Alexander Buschek - Reply

Holy cow. I rewarded myself 5 gummi bears for that. Praying that there is nothing to be redone, this was rough.

Dieter Rosch - Reply

Pheew… Glad it’s done :) I would suggest around 2h assembly time.

Francesco Santini - Reply

Finish Line

325 other people completed this guide.

Jakub Dolezal

Member since: 02/20/2017

68,245 Reputation

132 Guides authored

45 Comments

Step 32-33: first you're tinkering with the filament sensor, then the next step is to pull a cable through the x-carriage back…

Took me a while to figure out that it was the - extruder- cable and not the- filament sensor cable-.

It is written, but just looking at the drawings, I was sure it was the same cable. Oh well RTFM to me :-p

Kenneth - Reply

Hi Kenneth, I'm sure you wanted your printer up and running asap and this is were some mistakes happen :) In case of issues with the assembly, always double check the previous steps.

Jakub Dolezal -

An hour and a hlaf, that part was pretty tedious. Putting the nuts in at 16 & 17 could probably be pushed down in order some. They were n’t used till quite a bit later, and kept falling out.

Scott - Reply

Step 28 needs a warning, some how I stripped the screw or it somehow the nut froze on the screw which led to the nut free spinning in the part. I ended up having to print another part.

Mike Carr - Reply

Hi Mike, can you please upload pictures or video? You can place them here: http://manual.prusa3d.com/Answers Thanks :)

Jakub Dolezal -

I had the same problem in step 28. Surprisingly he nut seized on the M3x10screw. Luckily I could still use the part because the nut had not fully bottomed in the hex when it happened. Removing the head from the screw to get it out was a bit of pain though.

Bo Gustafsson -

I had the same problem. I believe this step should be removed as the nut will be retained during, what is currently, step 30. I will also have to cut the bolt head off and I have not determine if I will need to reprint the part yet. Maybe in the future these components should be reviewed to relocate the retainer nut so that it is not so close to the bottom x bearing housing. I may reprint this piece with the wire harness bolt moved down 1-2mm.

Regards,

Jeff Underly -

I had the same problem with one “M3n” nut. Not sure how this might happen, but it seems that particular nut is not Metric - I tried it with several screws, the same behavior… I put that nut aside…

Alan Rusyak -

Step 40. Read the comments or there will be collision problems.

Bo Gustafsson - Reply

Anybody end with extra screws? I got two m18 and one m30….short with one m10 and took from spare.

Bill D - Reply

Yes, I had exactly the same amount of leftover screws.

Tomi Orava -

same here…………

Mike Cohen -

+1

12 characters

D Wellnitz -

Yes, one 30, two 18 and the itsy bitsy hex nut for the extruder

Philippe Lacoude -

Same for me, 2x M18, 1x M30

Leo -

Bondtech claims you should add grease to the shaft for the needle bearing.. am i missing the step in the instructions or shouldnt i add grease?

Daniel Hellström - Reply

Hi Daniel, during the assembly no grease is needed, only for later maintenance.

Jakub Dolezal -

I added a small amount of high temperature grease to each bearing. Just didn’t seem right putting them in there dry.

E Duane Rose -

Step 22 was very difficult to get the hex screw to stay in place in the ‘arm’ for the air blower fan. Perhaps a longer screw? Or a square nut/slot style here? I ended up using a large allen key (same size as the nut outer diameter) to press the nut in and flat for the screw to bite.

Cameron Lamont - Reply

Agreed. That needs to be a 20mm screw, or the mating plate needs to be 2mm deeper.

Mark Crawford -

On step 35, I could not for the life of me get the M3x10 screws to work. I resorted to using the spare M3x18 screws, and they worked like a charm. The problem was the M3x10 screws just werent long enough to get to the nuts for some reason.

Zachary Goyer - Reply

This section 5 took me about 3 hours 30 minutes to complete. This is my first ever 3D printer.

Kari Söderholm - Reply

Hi Jakub, could you see my comments in step 26? There’s a tip that will help people prevent damage to their extruder motor cables. More info is needed on how to properly route the cables into the channel in the X axis. Thanks!

Corey Dryja - Reply

Hi Corey, yes feedback noted, step will be reshoot as soon as possible.

Jakub Dolezal -

1 hour 40 minutes. (Plus 15 minutes spent using a sharpie to color the noctua fan black ^_^ )

Zaz - Reply

This is my first 3D printer and this stage took me 2 hours 5 minutes, I found the online instruction images much clearer and the comments very helpful and yes I had 2 m18 and 1 m30 extra and 1 m10 short but used one left from an earlier stage.

Graeme Strahan - Reply

The label for 5. E-AXIS is not complete. There is two Different Bondtech pulleys in the bag, two needle bearings and one axle that is not mentioned on the label. There was also one additional lock screw in my package.

And for the assembly you need 7M3x18, and 4M3x30 and 10 M3x10.

I had one M3x10 to few and 1 M3x30 and 2 M3x18 over in the end as described above.

Peter Törlind - Reply

Hi Peter, thank you for the feedback. The manual is describing both pulleys with respect to their differences. Additional lock screws serves as a spare part. Missing M3x10 should be replaced by one from the spare bag (see step 47).

Jakub Dolezal -

You left out the “have a Gummy Bear” instruction!

Catherine Williams - Reply

Hi Catherine, I wasn't expecting you have some left :D

Jakub Dolezal -

I definitely miss the gummy bears after 2 hours of work!

Miroslav Piencak - Reply

That was brutal. Lots of things to check and double check, and a lot of fiddly bits that wouldn't stay in place. Managed it with gummy bears to spare, though!

Only time so far that I didn't follow the instructions was for inserting the nylon filament. With the cover on there and all the wires in the way I just couldn't manage to get the nylon in the hole, so I did as suggested in the comments and removed the cover, firmly inserted the nylon and then put everything back. Problem solved.

Bas - Reply

2 hours!! :-) Looks good and I’m done for the night. I’ll have to pick up section 6 tomorrow.

Sara Simpson - Reply

I would take away the 30 points awarded above. Step 38 needs more information!!!

Jim - Reply

I wound up splitting my time over three different session on this step, but two hours seems like a reasonable estimate. I’d also suggest (agreeing with other commenters) that inserting the nylon filament should be done *before* the back goes on. Much easier to find the hole and get it inserted solidly. Then simply start the cable insertion step with a comment to slip the back plate over the filament first, then proceed to the cables.

Bill Magley - Reply

After all that, I see that I have leftover a single very small part which I am certain is a “lock screw” for the pulley in steps 11 and 12. I am 100% certain that I tightened one lock screw in step 12. Please tell me that the pulley only has a single lock screw, or that “one is enough”. Otherwise, warn people to check the pulley and make sure both are in place.

Joel Kozikowski - Reply

Hi Joel, we are sending two lock screws, one is in the pulley already. Second is a spare, so you should be ok.

Jakub Dolezal -

Whew. Good to know that the tiny setscrew was an extra. Finding extra parts after the end of the build, especially one as difficult as this was, makes me very nervous.

Pete Lorimer -

took me 3 hours and 50 mins. Pretty much a beginner with two left hands tho

I feel like the part where you screw the “door” shut (step 15) should give you some sort of pointer besides “screw heads visible” as to how tight it has to be. I tightened it until I was able to push a filament in with medium force (suppose the motor would help in normal operation)

David Kaufmann - Reply

Might want an extra reminder that the plastic is fragile; the screw mount breaks fairly easily and this one is a bummer to have the single screw break on

Stephen Hitchcock - Reply

Hi Stephen, which part you had problem with? Parts are reinforced to sustain certain loads, but you can still crack them if you use too much force.

Jakub Dolezal -

I ran a stop watch on my actual assembly time (including RTFM) - just under 1.5hrs. With other normal breaks, and gummy treats, 120-150min is reasonable time estimate.

Mark Deley - Reply

Based on my experience with this section (and having never actually even SEEN a 3D Printer in person before the one I’m currently building) I think a reasonable amount of time for this section would be 2 hours 30 minutes to 3 hours. It took me 2 hours and 47 minutes and I’ve been coming in at the top end of the “par” time for all the other sections.

Dave S - Reply

Wow! With the exception of the nut seat on the ‘arm’ that sticks out to hold the fan, the precision with which all these bits have been made is astounding. For them all to come together so perfectly so that what was a dozen bits ends up as one seamless whole has put a smile on my face for the entire chapter.

Yes there were a couple of places where I had to re-read the instructions and look more closely at the photos, but in the end the instructions and the photos were correct and complete - I just had to take the time to understand them before ploughing on. One hour fifty five minutes. A nice cuppa tea now as a reward. Gummi Bears will all have to wait until the first print comes off.

Andy Timmons - Reply

I did not think this part was all that difficult. It was just tedious. There are a lot of steps in this section. Just take things one step at a time. It’s easy.

Vance Howard - Reply

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