Needle-nose pliers for tension check.
  • Needle-nose pliers for tension check.

  • 2.5mm Allen key for M3 screws

Add Comment

For the following step, please prepare: Z-axis-bottom-left (1x) Z-axis-bottom-right (1x)
  • For the following step, please prepare:

  • Z-axis-bottom-left (1x)

  • Z-axis-bottom-right (1x)

  • M3x10 screws (6x)

  • Place the printed parts next to the frame. See the picture for CORRECT ORIENTATION (the small circular openings must be facing out).

  • Tighten each printed part with M3x10 screws.

  • Don't use excessive strength during tightening! In case of increased resistance, try to place the screws from the other side to "clean up" the hole. Then return to the front side.

There is a little bit of play in these brackets during tightening. I didn't realize it when I built my mk2s and it caused a slight misalignment. This time, I decided to use a machinist’ square here to ensure these were square with the frame. Worked great.

Steven Underwood - Reply

Thanks for the tip. Mine were quite misaligned until I used a square to align it.

Andreas Sjolund -

Thanks for the comment Steven, I had mounted my right Z-Axis motor and noticed that the leadscrew was not vertical. I took it off, squared up the top of the bracket to be at exactly 90 degrees to the frame side and it corrected the problem with the leadscrew. It would be worth adding this to the instructions. All you need is anything with a right-angle to square it up.

Kevin Gallagher - Reply

Thanks for the feedback guys, we will discuss a way to adjust the design to prevent misalignment.

Jakub Dolezal - Reply

For me a book works well to ensure the right angle to the frame.

Martin Wolker - Reply

The image shows an “A5” label. Mine is labeled “B1”

Øyvind Taknæs - Reply

Hi Øyvind, yes as the parts evolve we are changing labels on them.

Jakub Dolezal -

For the following step, please prepare: Z-axis motor (2x) Note each Z-axis motor has different cable length. The shorter one must be on the left side, longer on the right side.
  • For the following step, please prepare:

  • Z-axis motor (2x)

  • Note each Z-axis motor has different cable length. The shorter one must be on the left side, longer on the right side.

  • Z-screw-cover (2x)

  • Remove the trapezoid nuts from the motors. DON'T THROW them away, you will need them!

  • Screw the Z-screw covers onto both leadscrews.

  • Covers should be screwed fully to the motor, but not too tight! The motor must be able to spin freely!

My fingers hurt so bad :) … these were so tight it almost made me believe I created the threads as I was turning the leadscrew :) … I would have designed some tabs like those of a wingnut but shorter, 4-5mm deep to be able to grip the covers better. My 2c :)

Florian Ford - Reply

There are 2 extra components here that I have and have not found them in the manual. They are black printed cones shaped things that are loose. I have just scrolled down a bit on this page and see something like them at the end of the lead screws near the motor. Is this them? If so this is a big pain as I have my axes assembled and now need to disassemble them to put these on. Note they were supplied loose in my kit with no instruction as to what to do with them.

Stephen - Reply

Hi Stephen, check the second picture, those are called Z-screw-cover.

Jakub Dolezal -

Ah - apologies - I have now looked properly and see where they are mentioned above. My mistake :(

Stephen - Reply

No problem ;)

Jakub Dolezal -

Could you add a picture showing what “trapezoid nuts” are? Step 4 doesn’t use them and I don’t know what’s meant by this.

Peter Larsen - Reply

For the following step, please prepare: Z motor left (labeled Z axis left, shorter cable) Z motor right (labeled Z axis right, longer cable)
  • For the following step, please prepare:

  • Z motor left (labeled Z axis left, shorter cable)

  • Z motor right (labeled Z axis right, longer cable)

  • M3x10 screw (8x)

  • See the second picture. The motor with the shorter cable (red arrow) is on the left, the motor with the longer cable (orange arrow) is on the right!

  • Secure each motor with four M3x10 screws. Tighten evenly and carefully as you might break the printed parts.

Could you add a photo specifically showing the wire exit/orientation of the motors? Thanks!

Kenneth Albanowski - Reply

Agreed or just state the wires exit at the rear and route downwards in the slot used for the bottom fixing screw of the bracket.

Neale Brodie - Reply

Kenneth (@kalbanowski) and Neale (@jnb), thanks for the feedback, step will be updated. Motor wires must be facing the frame and there is a cut out for them on the lower edge of the frame.

Jakub Dolezal - Reply

To get the threaded rods quite center instead of having them to force into the top ends later it’s not a bad idea to check the alignment of the threaded rod with the two holes at the top of the frame before screwing the motor to the z-axis holders. I had to loosen the holders again and push them a bit while screwing them to the frame to get the threaded rods to be quite straight.

Uli Braun - Reply

Did as Uli to get the threaded rods straight. Just fasten the motor holder to the frame so that could be moved before mounted the motors. Then adjust the shaft in the middle of the two holes on top. Then removed the motors and and tighten the motor holder.

I also had some problem with the one of the threaded rods was leaning away from the frame, it diffed about 3 mm from bottom to top. It looks like the holder is not 90 degrees. I ended up to put washers between the motor and the motor holder (0,8 mm thick) to tilt the rod to the farm. The glue stick that comes with the printer works perfect to compere the distends between the frame and the threaded rod.

Mattias - Reply

For the following step, please prepare: Trapezoid nut (2x) M3x10 screw (4x) or M3x18 screw (4x)
  • For the following step, please prepare:

  • Trapezoid nut (2x)

  • M3x10 screw (4x) or M3x18 screw (4x)

  • Starting X-end version B6 you need longer screws M3x18. In the first batches (February 2018) the screws are in a separate bag.

  • M3n nut (4x)

  • Turn the X-axis upside down and insert nuts into traps on both X-ends.

  • In case you can't press the nuts in, don't use excessive force. First, check that there isn't any obstacle in the nut trap.

  • Note: Design of your X-end printed parts might slightly differ, but the assembly process is the same.

First, check that there isn't any obstacle in the nut trap.

Keith Manley - Reply

Hi Keith, sentence rephrased, thank you.

Jakub Dolezal -

Why no thread lock! :P

Mr Cookie - Reply

Carefully rotate  the X-axis onto its backside. Insert the trapezoid motor nuts to each X-end.
  • Carefully rotate the X-axis onto its backside.

  • Insert the trapezoid motor nuts to each X-end.

  • Note the correct orientation of the trapezoid motor nuts!

  • Tighten the nuts with M3x10 screws or with M3x18 screws. Longer screws are needed in case of X-end version B6 and newer.

  • You can use any of all four holes on the trapezoid motor nuts.

  • Note: Design of your X-end printed parts might slightly differ, but the assembly process is the same.

Here should be the indication that the outer edges should coincide, otherwise the trapezoidal rods will later touch the upper guide which leads to rattling

Gerhard Kunz - Reply

The nuts that hold these screws in place fell out really easily for me. Perhaps this stage should be done earlier? when you have both of the axis ends still off the rods?

Alistair - Reply

FYI I had overtightened these bolts which caused my Left Z axis motor to have trouble turning and thus caused the calibration to fail. I loosened it a bit and it turned just fine.

Andreas Sjolund - Reply

Aside from the X-axis, please prepare for the following step: Smooth rod (2x) Carefully slide the X-axis on the trapezoid screws. By rotating both screws simultaneously let the X-axis slide until both trapezoid screws are visible.
  • Aside from the X-axis, please prepare for the following step:

  • Smooth rod (2x)

  • Carefully slide the X-axis on the trapezoid screws. By rotating both screws simultaneously let the X-axis slide until both trapezoid screws are visible.

  • Make sure the top smooth rod of the X-axis and the lower edge of the frame are parallel.

  • NOW, PLEASE BE VERY CAREFUL! Gently insert the remaining smooth rods through the bearings on the X-axis all the way down into printed parts, do not apply too much force and do not tilt the rod!

  • In case you manage to push out balls from the bearings, please count them. One or two balls are ok, if there are more of them, please consider ordering new bearings.

  • Note: Design of your X-end printed parts might slightly differ, but the assembly process is the same.

I missed the smooth rods part here…. …found out after calibrating part

printminion - Reply

Hi Printminion, was it unclear from the text or did you just follow the pictures?

Jakub Dolezal -

I’m having a problem where one the the trapezoid nuts is difficult to put on the threaded rod. Is this ok? I have to use a lot of force to slide the x axis down. I tried printing replacement nuts but those are hard to turn too.

John Helgeson - Reply

I found that sliding the nut up and down on the leadscrew a few times helped loosen up the fit a bit. The one of the left motor was far tighter than the right one in my kit.

Robert Hunt -

Hi John, the trapezoid nuts should be running smoothly and I haven’t encountered issues with them so far. Make sure your X-axis isn’t wider or inclined, this might cause increased friction.

Jakub Dolezal -

For the following step, please prepare:

Smooth rod x2

Robert heller - Reply

Hi Robert, thanks for noticing. Since the rods are already on your working bench (table) and it is the last couple, I assumed to instruct you just to use them.

Jakub Dolezal -

Agree. I would have missed this step. I read it but confused because I didnt realize that the smooth rods were part of this step. Actually, I’m building this thing a few hours at a time here and there so it’s been awhile since I last saw or used smooth rods. So making this extra clear in the steps would be helpful.

Andreas Sjolund -

I agree, and Jakub’s reply makes little sense since all other steps specify exactly the parts needed to complete the step, regardless of whether they are “already on the workbench” or the “last couple” parts. If the instructions are to be clear and trustworthy, they need to be consistent.

Guido Kimble -

Hi Guido, you’re right step instructions will be updated ;)

Jakub Dolezal -

One thing I noticed is that the x axis bearings slid down the plastic holders when I put the rods in. I’m hoping this is ok since the x axis steps indicated that the bearings should be somewhat flush to the top and bottom of the plastic piece holding them (with a gap in between). I pushed the bearings back into place but not sure if they will just fall down again and if it will impact the printer in anyway.

Daniel Lipsky - Reply

Hi Daniel, it the best scenario the bearings should be aligned with both top and bottom edges of the X-ends (printed parts). However, slight movement in the printed part should be ok.

Jakub Dolezal -

We should put the trapezoidal by hand on the rods before screwing them at step 6. Its very easy to damage the trapezoidal nut because they are hard to put on

there is no warning except ‘carefully screw the trapezoidal’.

Is it a problem if the nut is hard to turn ?

Jlevray - Reply

Hi Jlevray, different approach during the assembly might brings issues. Putting on the trapezoidal nuts shouldn’t be hard, it should be smooth. If you have issues, please try to put on the nut without the X-axis. If everything works fine, then your X-axis is either too wide or assembled inclined, which is causing tilt between the nut and the trapezoid screws.

Jakub Dolezal -

I did damage both trapezoidal nuts using the standard instructions as the metal screws can easily cut into the starting thread while trying to find the right alignment. That led to endless debugging about why the Z-axis didn’t work correctly.

I agree with Jlevray and strongly recommend carefully threading the nuts by hand first and screwing them to the X-axis second.

LaurentR -

Add one more to the agree with screwing on the nuts first. This was not an issue with the MK2, but seems harder with the MK3. Perhaps the spacing is slightly different. If you goof up the nut, you will either spend a ton of time trying to recut the threads with the leadscrew, or find an alternate solution such as printing temporary ones or stealing them from another printer as I did in the meantime. Mine was really tight right out of the box, so I am not sure whether it is the part or the process, however there is little left to guesswork if threaded on before being locked in.

Douglas Shelfoon - Reply

I’m also struggling with one of the trapezoidal nuts - it’s far too tight and I suspect it is causing the calibration failures that I’m now seeing. I’ve tried swapping the left nut with the right, and the same problem persists with just the one nut. I don’t recall putting it on awkwardly, but I might have damaged it. Although, it was also quite hard to remove from the screw shaft straight out of the box. It would be great if a spare was included with the kit!

Sean - Reply

I had the same problem. i just chatted with support and they are sending my a new nut.

Joe -

Hi Sean, the nuts are part of the Z-axis motors. In case yours are too tight, please contact our support.

Jakub Dolezal -

Similar problem :-(

I may have damaged my trapezoidal nut.I was having a tough time with step “slide the X-axis on the trapezoid screws. By rotating both screws simultaneously let the X-axis slide until both trapezoid screws are visible. “

After several times attempts i tryed running the nut backwards, and feeling the lip of the nut fall off the thread.

One of them was impossible to start with out putting some torque on it.

Now the left side X-access is very stiff.I removed the nuts from the x axis .

1 nut is very tight fit to the lead screws.

If i need to order new nuts please advise.

Do you guys sell ball caps ?

Joe - Reply

Hi Joe, please discuss this issue with our support team (info@prusa3d.com). The nuts shouldn’t be preventing you from assembling the X-axis.

Jakub Dolezal -

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

  • Z-axis-top-left (1x)

  • Z-axis-top-right (1x)

  • M3x10 screw (4x)

Add Comment

Place the Z-axis-top-left part on the rods and align it with the frame. Ensure the holes in the printed part are fully aligned with the holes on the frame. Use two M3x10 screws to tighten the Z-axis-top-left part.
  • Place the Z-axis-top-left part on the rods and align it with the frame.

  • Ensure the holes in the printed part are fully aligned with the holes on the frame.

  • Use two M3x10 screws to tighten the Z-axis-top-left part.

  • Don't use excessive strength during tightening. In case of increased resistance, try to place the screws from the other side to "clean up" the hole. Then return to the front side.

  • Repeat this step on the other side of the frame with Z-axis-top-right printed part.

  • Note: Design of your X-end printed parts might slightly differ, but the assembly process is the same.

refering to MK2 manual step 12:

“Check both leadscrews in the upper part of printer, they shouldn't touch the edges of the printed part. If so, release the motor holder at the bottom and slightly move it. “

You cannot see it from the top because the surface is full and solid. My leadscrew hits the edge what causes noise on fast movements of the x-axis.

It is much easier to adjust the motor holder now instead after fully assembled and finished wire management.

Heiko Schultz - Reply

Hi Heiko, the Z-axis design was changed to prevent misalignment of the leadscrews. I will discuss this with devs, thank you for the feedback.

Jakub Dolezal -

it’s not an issue of the design, it’s just the assemble instruction that doesn’t highlight this. From below I can see if it is centered or not.

Heiko Schultz -

Hi Heiko (@predatorjr), the design was changed to align the rod correctly by itself and user shouldn't be checking the position, that is why it is not mentioned in the guide.

Jakub Dolezal -

I had an issue with the screw threads on the frame for the top right Z axis part.  I don’t think they were tapped properly because the screws were extremely tough to get in.  This was not an issue with the 3d printed part as I tried to work the screws in the holes without the 3d parts as well.  Ultimately, I had to carefully use my drill and was able to get the screws to go all the way in.  The top right 3d printed part does not sit tightly onto the smooth and threaded rod but there’s no play if I wiggle them with my hand.

Shouldn’t be an issue but wanted to share my feedback.

Corey Dryja - Reply

Starting mid of February 2018, the MK3 kit is shipped with improved X-carriage.
  • Starting mid of February 2018, the MK3 kit is shipped with improved X-carriage.

  • Compare yours against the picture and choose from following:

  • The old design is on the left side of the photo. Please proceed to Step 19

  • The new design is on the right side of the photo. Please proceed to Step 11

Add Comment

Insert the flat part of the X-GT2 belt (850 mm) into the X-carriage as in the picture.
  • Insert the flat part of the X-GT2 belt (850 mm) into the X-carriage as in the picture.

  • Use a screwdriver or the smallest Allen key to push the belt in.

Add Comment

Guide the X-axis belt through the X-end-idler, around the 623h bearing with the housing and back. Continue with the belt through the X-carriage. Note there are slots below the belt, those will be used for cables. Guide the X-axis belt through the X-end-motor, around the GT2-16 pulley and back.
  • Guide the X-axis belt through the X-end-idler, around the 623h bearing with the housing and back.

  • Continue with the belt through the X-carriage. Note there are slots below the belt, those will be used for cables.

  • Guide the X-axis belt through the X-end-motor, around the GT2-16 pulley and back.

Add Comment

Before you continue to guide the belt through the X-axis, please release two M3 screws on the X-end. Rotate the X-axis motor as indicated towards the frame.
  • Before you continue to guide the belt through the X-axis, please release two M3 screws on the X-end.

  • Rotate the X-axis motor as indicated towards the frame.

  • Insert the flat part of the X-GT2 belt into the X-carriage as in the second picture.

  • Use a screwdriver or the smallest Allen key to push the belt in.

  • There will be belt overhang on this side, DON'T TRIM IT yet.

Add Comment

Using right hand rotate the motor to its original position and hold it. Using two fingers on your left hand push the belt together. Very small force should be needed for bending the belt, BUT the belt shouldn't be bent by its own weight before being pressed with your fingers, it must be straight.
  • Using right hand rotate the motor to its original position and hold it.

  • Using two fingers on your left hand push the belt together. Very small force should be needed for bending the belt, BUT the belt shouldn't be bent by its own weight before being pressed with your fingers, it must be straight.

  • If you are struggling to rotate the motor back into position the belt tension is too high.

  • Depending on the belt being under or overstretched, adjust the amount of the belt in the X-carriage.

  • When done, rotate the motor to its original position and tighten the M3 screws again.

Add Comment

Both top and bottom part of the belt should be parallel (above each other).
  • Both top and bottom part of the belt should be parallel (above each other).

  • To adjust the belt position, release the screws on the pulley and move it slightly until you reach the best position.

  • Tighten both screws on the pulley.

Add Comment

Use the technique described below to test if the belt is properly stretched.
  • Use the technique described below to test if the belt is properly stretched.

  • Use pliers to hold the X-axis motor shaft.

  • Move the X-carriage towards the X-axis motor. Don't use excessive force.

  • If the belt is stretched properly, you should feel a resistance and the X-carriage won't move at all. If the belt is too loose, it will deform (create a "wave") and jump over the teeth on the pulley.

  • Belt too loose? Return to step 13 and repeat all steps until now. You have to rotate the motor and retighten the belt in the X-carriage. Shortening the belt length by moving one or two teeth outside X-carriage should be enough.

Add Comment

For the following step we recommend getting a white marker, but you can also trim the belt without it. Measure the part, which must be trimmed and gently take the end of the belt away, from the X-carriage, but make sure at least 3-4 teeth are still in the X-carriage, as you don't want to lose the tension. If possible make a mark, where to cut the belt. Ensure again your mark is in the correct position and the belt is still stretched.
  • For the following step we recommend getting a white marker, but you can also trim the belt without it.

  • Measure the part, which must be trimmed and gently take the end of the belt away, from the X-carriage, but make sure at least 3-4 teeth are still in the X-carriage, as you don't want to lose the tension. If possible make a mark, where to cut the belt.

  • Ensure again your mark is in the correct position and the belt is still stretched.

  • Using pliers cut the belt and push it inside X-carriage. Use screwdriver or Allen key, if needed.

Add Comment

In this step, we will finish tensioning the belt. Please read the instructions first, your belt might have proper tension already. First, slightly release all the screws holding the motor, otherwise, the upper "tensioner" won't work (the motor must be able to move). Using Allen key start tightening the M3x18 screw inside the X-end-motor, but after each turn or two check the tension in the belt.
  • In this step, we will finish tensioning the belt. Please read the instructions first, your belt might have proper tension already.

  • First, slightly release all the screws holding the motor, otherwise, the upper "tensioner" won't work (the motor must be able to move).

  • Using Allen key start tightening the M3x18 screw inside the X-end-motor, but after each turn or two check the tension in the belt.

  • In Step 14, you were asked to have the belt a bit less stretched, however, for the optimal performance, the belt must be a bit harder to press with your fingers. Move the X-carriage all the way to the X-end-idler and try the belt tension in the middle of the X-axis.

  • When you achieve optimal tension, please tighten the screws again.

  • In case you experience X-axis failure during calibration or skipped layers in the X direction, you can adjust this screw accordingly. Tightening the screw stretches the belt. Releasing the screw has opposite effect. Each time don't forget to release the screws on the motor first.

  • Ready? Please jump to step Step 25

Add Comment

Insert the flat part of the X-GT2 belt (850 mm) into the X-carriage as in the picture. Press the belt all the way in, use a screwdriver or an Allen key. It's very IMPORTANT that the short end of the belt isn't sticking out of the X-carriage.
  • Insert the flat part of the X-GT2 belt (850 mm) into the X-carriage as in the picture.

  • Press the belt all the way in, use a screwdriver or an Allen key.

  • It's very IMPORTANT that the short end of the belt isn't sticking out of the X-carriage.

“Insert the flat part of the X-GT2 belt (longer one) into the X-carriage as in the picture.”

What you mean by “longer one”?

Austin Hampton - Reply

It seems to me the X belt is longer than the Y belt.. so if you unpacked everything all at once and not step by step “longer one” would tell you which is which.. but how you would get to this step with more than one belt from one kit is a mystery =)

Thomas Kasner -

Step description updated with exact length of the belt. It should be a check for those, who switch the belts by accident.

Jakub Dolezal -

I think it’s a mistake to “press the belt all the way in”. I think this is the reason that many people are experiencing belt rubbing on the front shoulder of the pulley and resultant belt twisting. Instead the belt should sit flush with the outer edge of the round mount.

Ken Hackbarth - Reply

Hi Ken, no it is OK as described in the manual. The belt should be completely pressed in. I need to see your printer, to examine the possible cause of the rubbing.

Jakub Dolezal -

Guide the X-axis belt through the X-end-idler, around the 623h bearing with the housing and back. Continue with the belt through the X-carriage. Note there are slots below the belt, those will be used for cables. Guide the X-axis belt through the X-end-motor, around the GT2-16 pulley and back.
  • Guide the X-axis belt through the X-end-idler, around the 623h bearing with the housing and back.

  • Continue with the belt through the X-carriage. Note there are slots below the belt, those will be used for cables.

  • Guide the X-axis belt through the X-end-motor, around the GT2-16 pulley and back.

Add Comment

Before you continue to guide the belt through the X-axis, please release two M3 screws on the X-end. Rotate the X-axis motor down. Insert the flat part of the X-GT2 belt into the X-carriage as in the second picture.
  • Before you continue to guide the belt through the X-axis, please release two M3 screws on the X-end.

  • Rotate the X-axis motor down.

  • Insert the flat part of the X-GT2 belt into the X-carriage as in the second picture.

  • Press the belt all the way in, use a screwdriver or an Allen key.

  • There can be a slight belt overhang on this side, no need to trim it.

When I was doing this step, the belt teeth were slipping over each other, even without significant tension. I concluded that the “pinch points” in the printed part (the X-carriage) were not tight enough. I cut 2 small squares of thin (0.25mm), hard plastic (from the plastic wrapper from the packaging of a 9v battery), and slid them in above the overlapping belt The location is pointed to by the upper green arrow in the second picture. It stopped the slipping and it worked perfectly after that.

Kevin Gallagher - Reply

Same problem, as soon as i try to tight with the motor, it slips…:-(. I agree with Gerhard, even if after trained myself on MK2, it seems easier to use this fixing belt today, when it holds something !

Jeremy -

A sugestion for a Version MK3S or MK4: another fixing for the belt.

It was a pain to get this in in the right position.

Gerhard Kunz - Reply

mk3.jpeg No problem here

Valentin Bulbuc - Reply

Using right hand rotate the motor to its original position and hold it. Using a finger on your left hand push the belt down. Some force should be needed for bending the belt, BUT don't try to overstretch the belt as you might damage the printer.
  • Using right hand rotate the motor to its original position and hold it.

  • Using a finger on your left hand push the belt down. Some force should be needed for bending the belt, BUT don't try to overstretch the belt as you might damage the printer.

  • If you are struggling to rotate the motor back into position the belt tension is too high.

  • Depending on the belt being under or overstretched, adjust the amount of the belt in the X-carriage.

  • When done, rotate the motor to its original position and tighten the M3 screws again.

Add Comment

Both top and bottom part of the belt should be parallel (above each other). To adjust the belt position, release the screws on the pulley and move it slightly until you reach the best position.
  • Both top and bottom part of the belt should be parallel (above each other).

  • To adjust the belt position, release the screws on the pulley and move it slightly until you reach the best position.

  • In case you can't make the belt parallel, check if the belt is properly inserted in the X-carriage.

  • Tighten both screws on the pulley.

If the pulley screws are not tightened really properly, it may cause a random x-axis layer shifting later, if they become loose!

Miroslav Piencak - Reply

I am having an issue with the belt touching the printed pat that holds the motor. It catches the side of the printed part away from the motor toward the rod and screw. I have tries pushing the the pulley all the way against the motor but it still will not clear the opening in the printed part as it passes through to the x-carriage. This causes the belt to tilt in toward the front side and away on the back side so it looks like a long V that does not quite connect. I was thinking I might cure this by placing washers between the printed part and the motor to give me additional shaft so I can push the pulley back far enough to clear the opening in the printed part. However, this seems likely to create additional problems later. I suppose a stiff gasket material that covers the top of the motor might be less risky, would need to search for something like that. Is there another adjustment I missed here that might cure this problem? It seems to me this may cause the belt to be unstable and wear badly if not fixed.

Harry Townsend - Reply

Solved my problem, I put the pulley on backwards…

Harry Townsend - Reply

Use the technique described below to test if the belt is properly stretched.
  • Use the technique described below to test if the belt is properly stretched.

  • Use pliers to hold the X-axis motor shaft.

  • Move the X-carriage towards the X-axis motor. Don't use excessive force.

  • If the belt is stretched properly, you should feel a resistance and the X-carriage won't move at all. If the belt is too loose, it will deform (create a "wave") and jump over the teeth on the pulley.

  • Belt too loose? Return to step 12 and repeat all steps until now. You have to rotate the motor and retighten the belt in the X-carriage. Shortening the belt length by moving one or two teeth outside X-carriage should be enough.

Small gripe: It should say to return to step 20. Step 12 is for the new design X-carriage.

Torsten Lif - Reply

Z-axis is done! Time for another gummy bear. You still have some right? :)
  • Z-axis is done! Time for another gummy bear. You still have some right? :)

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

  • Checked everything? It's time for: 5. E-axis assembly

Add Comment

Finish Line

160 other people completed this guide.

Jakub Dolezal

Member since: 02/20/2017

54,760 Reputation

114 Guides authored

4 Comments

One hour, tensioning was a bit time consuming.

Scott - Reply

35 minutes. :D

Zaz - Reply

Difficult to insert the beginning of the belt into the carriage but not the end. Some slight production variation?. Managed anyway. Looking good at this point.

Henry Casson - Reply

Up until this part, I used the printed assembly instruction - because it is easier to have a book on the work table than a computer. But the printed pictures of the black X-carriage and the black belt were impossible to see in any detail, so I had to come here. I think some sketches of the belt path would be a huge improvement.

Torsten Lif - Reply

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