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

    • 2.5mm Allen key for M3 screws

    • 1.5mm Allen key for nut alignment

    • Philips screwdriver to tighten PSU and HB cables

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

    • Einsy-door (1x)

    • Einsy-hinge-top (1x)

    • Einsy-hinge-bottom (1x)

    • M3nS nut (1x)

    • M3x10 screw (2x)

    note: screws are in a box, not a bag like most sections.

    Ben Renneberg - Reply

    Hinge on the bottom hinge broke.. be veeeery careful….

    Hauke Oldenburg - Reply

    Screws are in the box with the einsy board

    Terry Sherman - Reply

    I received two top hinges and no lower hinge.

    hegn0015@umn.edu - Reply

    Hi,

    You can print the missing part yourself: https://www.prusa3d.com/prusa-i3-printab...

    Or contact our tech support (info@prusa3d.com) - we can send you the missing part :)

    Filip M - Official Prusa CS -

  3. Insert M3nS nut all the way in. You can use the small screw driver to push it down if needed. Check the proper alignment with the Allen key.
    • Insert M3nS nut all the way in. You can use the small screw driver to push it down if needed.

    • Check the proper alignment with the Allen key.

  4. Turn the rear side of the printer towards you.
    • Turn the rear side of the printer towards you.

    • Holes with blue arrows will be used to mount the hinges for the Einsy-door.

  5. Take the Einsy-hinge-bottom and push M3x10 screw through. Note there is a cutout for the screw's head in the printed part. Locate the hole for the lower hinge.
    • Take the Einsy-hinge-bottom and push M3x10 screw through.

    • Note there is a cutout for the screw's head in the printed part.

    • Locate the hole for the lower hinge.

    • Place the hinge on the frame and tighten the screw. The hinge must be facing upwards.

    Be careful the hinge breaks easily.. it happened to me.

    Hauke Oldenburg - Reply

    Thanks, held on to mine with vice grips from the meaty part. Good looking out!

    Christopher Rouxel -

  6. Place the Einsy-door on the lower hinge. Take the Einsy-hinge-top and push M3x10 screw through. Assemble the Einsy-hinge-top in the door and mount it to the frame.
    • Place the Einsy-door on the lower hinge.

    • Take the Einsy-hinge-top and push M3x10 screw through.

    • Assemble the Einsy-hinge-top in the door and mount it to the frame.

    Fitting the door at this stage only gets in the way of all other operations with the einsy enclosure. After the connection check would be more sensible

    Martin - Reply

    Just broke the male end off of the Einsy-hinge-top. What hind of material is it? Can I glue it back on?

    David 01/03/2019

    David Johnson - Reply

    Hi David,

    It’s printed from PETG, but you can also re-print it from any other material. You can re-glue it in the meanwhile.

    Filip M - Official Prusa CS -

  7. For the following step, please prepare: Textile sleeve 6 x 300 mm (1x) Zip tie (1x)
    • For the following step, please prepare:

    • Textile sleeve 6 x 300 mm (1x)

    • Zip tie (1x)

    • Wrap the sleeve around the X-axis motor cable. The sleeve is shorter, than the motor cable.

    • Secure the sleeve using a zip tie, you have to tighten the zip tie firmly and it is only a temporary fix until the Einsy case is assembled, but you can leave the zip tie in place afterwards.

    I received a spiral instead of a textile sleeve…?

    Phil - Reply

    Hey Phil, you can also use the spiral wrap instead of the textile one.

    Filip M - Official Prusa CS -

    I forgot about this being temporary, and then went back and tidied up the motor end of the textile wrap. The zip tie doesn’t really grip. I may just remove it, but it’s on there for now.

    Matt Laudato - Reply

  8. For the following steps, please prepare: Einsy-base (1x) M3x10 screw (6x)
    • For the following steps, please prepare:

    • Einsy-base (1x)

    • M3x10 screw (6x)

    • M3nS nut (4x)

    • M3n nut (4x)

    • EINSY RAMBo motherboard (1x)

    • Einsy-base version B7 has a maintenance opening for the RPi Zero W. If you intend to use this mini computer, you can carefully cut the piece of the plastic now. More details here: Octoprint for the MK3 (manual.prusa3d.com)

    With the Einsy case I had run out of M3x10 screws. You will need to add more spare screws for this case and M3 square nuts also, I had to use my last 4 spare nuts on this case also. I had to purchase extra screws from Amazon.

    Stephen Harbin - Reply

    Hi Stephen, in the assembly kit this is covered. In case you print the new parts on your own, you need extra 4x M3x10 screw and 4x M3nS.

    Jakub Dolezal -

    The EINSY RAMBo motherboard was shipped with an open Static Shielding Bag. Is that normal? It looked like it had been opened before.

    Lea T - Reply

    Hi,

    Yes, it’s normal - the board doesn’t need to be fully sealed for transportation.

    Official Prusa Support

    Filip M - Official Prusa CS -

  9. There are two designs to the EINSY board. See the pictures to recognise your version: Version A: LCD connectors are used directly on the EINSY RAMBo board.
    • There are two designs to the EINSY board. See the pictures to recognise your version:

    • Version A: LCD connectors are used directly on the EINSY RAMBo board.

    • Version B: LCD connectors are part of the daughterboard.

    • The daughterboard is preassembled in our factory. Do not remove it!

    • There is no functional difference between both solutions from the user point of view, the connectors are just shifted to a different position.

  10. Insert four M3n nuts in nut traps. Slide EINSY inside the base and tighten it with four M3x10 screws.
    • Insert four M3n nuts in nut traps.

    • Slide EINSY inside the base and tighten it with four M3x10 screws.

    • Tighten the screws carefully, you can damage the board.

    • Use the needle nose pliers to help with positioning the screws.

    I ended up putting the screws on the board first then finagling it into place. This avoids the screw placement challenges when the board is already in the housing.

    Diana Jarrell - Reply

    I suggest swapping steps 10 and 11. That way it’s easier to get the nuts into the tight slots without risking damage to the EINSY board.

    Tony Morgan - Reply

    I agree with swapping steps 10 and 11 …as long as the nuts are always interference fits to the slots ….ie, the nuts don’t fall out.

    Todd Podbielski - Reply

    Hey Todd,

    If the nuts are loose, then you can try pulling them more with a screw before mounting the Einsy board.

    Filip M - Official Prusa CS -

    In my case, the nuts were loose. I used masking tape to temporarily hold the nuts in place while installing the board.

    Steve Peters - Reply

  11. Take the four M3nS nuts you've prepared earlier and insert them in the Einsy case the following way: Two nuts inside the heatbed holder (note one slot is from the inside of the cover) Two nuts inside the extruder cable holder.
    • Take the four M3nS nuts you've prepared earlier and insert them in the Einsy case the following way:

    • Two nuts inside the heatbed holder (note one slot is from the inside of the cover)

    • Two nuts inside the extruder cable holder.

    • Press the nuts all the way in.

    • Check the proper alignment using an Allen key.

    Three out of the four M3nS nut slots were too small requiring careful filing before they could be installed. Good think I had a set of small files!

    Jerry Vaughn - Reply

    I also had to use a tiny file to open up the holes for the M3nS nuts.

    Liquidlogic -

    I had the same experience as Jerry did, the slots were very tight. Luckily I was able to open them just enough by inserting the closest sized hex wrench and spinning it around to open just enough space. I did have to use quite a bit of force to get them to go in. In future releases it might make sense to do this part before step 10. I was worried about damaging the board.

    Matt Burke - Reply

    I think if I had known this was coming up, I would have preferred to put these nuts in before mounting the Einsy board. Less chance of damaging it.

    Mark - Reply

    I have to agree with the comments above. I’m glad the slots are tight, so I don’t have to worry about losing the nuts before they’re secured with the screw, but the force required is disconcerting with the board mounted. I don’t see why this can’t be done first, which would be safer.

    Matthew Mackey - Reply

    Inserting the cable clamp retention nuts in the case before the electronics would make this operation far more easy

    Martin - Reply

    I used an X-Acto knife to shave away a bit of extraneous plastic inside the slots and that allowed the nuts to finally go in.

    Jeff Pistone - Reply

    It would be good to specify the insertion of the M3nS nuts into the traps for the heat bed and extruder cables as separate points in the text for people who don’t scrutinize the pictures, as myself. Otherwise it is easy to forget.

    Mikael Djurfeldt - Reply

    Hi, thank you for your feedback. We will improve the note.

    - Official Prusa Support

    Martini H. - Official Prusa CS -

    I listened to Mark and inserted S nuts before motherboard and didn’t have much trouble.

    Vjekoslav Kopacin - Reply

  12. Holes with blue arrows will be used to mount the Einsy-base. Insert M3x10 screws in the holes and tighten them just slightly.
    • Holes with blue arrows will be used to mount the Einsy-base.

    • Insert M3x10 screws in the holes and tighten them just slightly.

  13. Before mounting the base on the frame, take the cable from X-axis motor (see the yellow label) and plug it in the EINSY. Push the textile sleeve in the slot and leave some slack of the cable along the board (don't stretch the cable). See the slots on the printed part, which will be used for the M3x10 screws (those are already on the frame).
    • Before mounting the base on the frame, take the cable from X-axis motor (see the yellow label) and plug it in the EINSY.

    • Push the textile sleeve in the slot and leave some slack of the cable along the board (don't stretch the cable).

    • See the slots on the printed part, which will be used for the M3x10 screws (those are already on the frame).

  14. Slide the Einsy-base on the prepared M3x10 screws and align it with the edge of the Z-axis frame. Using 2.5mm Allen key tighten both screws. See second and third picture. Using 2.5mm Allen key tighten both screws. See second and third picture.
    • Slide the Einsy-base on the prepared M3x10 screws and align it with the edge of the Z-axis frame.

    • Using 2.5mm Allen key tighten both screws. See second and third picture.

    How are there no comments on this step? This is impossible, the board is in the way. The solder for the through-hole piece next to the screw is too tall

    Evan Fort - Reply

    turn the screws until you can slide the base in with a little pressure, then with your tongue out the left side of your mouth, uut the ball end of the hex key through the ventilation slot on the einsy base.

    Gary Bonnor -

    Solution - screw in the screw more so there isn’t much left to screw in. Then, press it all together and since the screw has moved in a bit, you can get around the solder joint and turn it another 1/4 turn to make it tight.

    Evan Fort - Reply

    Hey Evan, if you follow the manual closely you’ll see that it’s not hard at all - just need to use the key at the correct angle.

    Filip M - Official Prusa CS -

    Continue to love my balldriver set!

    Bob Hayssen - Reply

    It just needs some patience, but it works good.

    Stefan Merki - Reply

    Two things. First, put the screws into the frame as far as possible while still being able to slide the base on. Second, make sure the base is pushed in all the way such that the edge of the housing is flush with the frame, otherwise it will seem impossible to get to the top screw.

    Ybl84f1 - Reply

    Hi,

    As long as you’re using the correct allen key, neither of the screws will be hard to reach.

    Official Prusa Support

    Filip M - Official Prusa CS -

    works like a champ and love the design of how you access the one screw.

    ajacks - Reply

  15. In the following steps, we will manage all the cables on the printer. We've tested several ways and this seems to be the most efficient.
    • In the following steps, we will manage all the cables on the printer. We've tested several ways and this seems to be the most efficient.

    • In the upcoming steps, please tighten all zip ties carefully as you might pinch/break the cables.

    • Turn the printer on the PSU side and start from the bottom all the way to the top.

  16. Start with the Z-axis motor (right). Slide the zip tie through the circular holes in the frame to create a loop.
    • Start with the Z-axis motor (right).

    • Slide the zip tie through the circular holes in the frame to create a loop.

    • Push the cable gently in the zip tie and tighten it so it is snug and holding the wires. Be careful not to over tighten the tie as it can cut the wires . Cut the remaining part.

    One might forget there are 2 Z axis motors, the one pictured here is the one next to the power supply which should be resting on your work surface.

    Ybl84f1 - Reply

  17. Continue upwards and using another zip tie create the next loop. Insert  Z-axis cable and all cables from the PSU. Make sure all the cables are below smooth rods and not interfering with the Y-carriage.
    • Continue upwards and using another zip tie create the next loop.

    • Insert Z-axis cable and all cables from the PSU. Make sure all the cables are below smooth rods and not interfering with the Y-carriage.

    • Push the cable gently in the zip tie and tighten it so it is snug and holding the wires. Be careful not to over tighten the tie as it can cut the wires . Cut the remaining part.

    There is no zoom-in version of the first picture.

    getabyte1432@gmail.com - Reply

    Hi there! It works for me, just click on the magnifying glass.

    Martin L. - Official Prusa CS -

  18. Continue upwards and using another zip tie create the next loop. Insert Y-axis motor cable to the bundle.
    • Continue upwards and using another zip tie create the next loop.

    • Insert Y-axis motor cable to the bundle.

    • Push the cable gently in the zip tie and tighten it so it is snug and holding the wires. Be careful not to over tighten the tie as it can cut the wires . Cut the remaining part.

  19. Take the LCD cables and gently push them in the aluminum extrusion. Leave some slack, do not stretch the cables too much. Use the whole length of the extrusion. Bend the cable bundle down for now.
    • Take the LCD cables and gently push them in the aluminum extrusion. Leave some slack, do not stretch the cables too much.

    • Use the whole length of the extrusion.

    • Bend the cable bundle down for now.

    • Carefully fold the LCD cables around the frame.

    I found this step very difficult. Getting the cable in without flexing it too much was a real problem.

    Keith Spitz - Reply

    No worries, this is rather a nice-to-have part of the assembly, nothing crucial.

    Martin L. - Official Prusa CS -

    Just a reminder, you’re threading the cables in the SIDE of the aluminum extrusion, not the BOTTOM where the rubber feet are. Maybe it’s just too late at night but it took me a try before I realized this.

    Ybl84f1 - Reply

    YES. It is very unclear from the text where to do this, and I nicked a wire removing the cables.

    Jeff Pistone -

    Thank you!!!

    Bill the Cat -

    I also thank you. I didn’t catch this until after I already put them in the bottom and then read your comment. I had to redo it. Should have read your comment first!

    Ron Nunn -

    Please have TWO gummy bears for me, with my thanks!!

    Frank Paynter - Reply

  20. Continue upwards and using another zip tie create the next loop. Take the bundle of cables and place it over the LCD cables.
    • Continue upwards and using another zip tie create the next loop.

    • Take the bundle of cables and place it over the LCD cables.

    • Push the cables gently in the zip tie (excluding the LCD cables) and tighten it. Cut the remaining part.

    This step was difficult as well. Same concerns about over-flexing the ribbon cables. Some better cable management approach for the ribbon cables would be nice.

    Keith Spitz - Reply

  21. Slide the zip tie through the circular holes in the frame to create a loop. This time place the LCD cables carefully in the zip tie. Insert the Z-axis left motor cable and all cables from the bundle.
    • Slide the zip tie through the circular holes in the frame to create a loop.

    • This time place the LCD cables carefully in the zip tie.

    • Insert the Z-axis left motor cable and all cables from the bundle.

    Rubber feet should be taller. this cable bundle loose and pretty flat but it will still touch the table.

    Will - Reply

    Hello Will,

    Make sure to follow all the steps carefully and the bundle won’t touch the table.

    Filip M - Official Prusa CS -

    My bundle was touching the floor as well. Cut the tie, reorganized the bundle a bit, and now it clears the floor easily. I think these (Prusa) guys have done this once or twice before ;-).

    Frank Paynter - Reply

  22. Push the cables gently in the zip tie, before you tighten the zip tie, read the next point.
    • Push the cables gently in the zip tie, before you tighten the zip tie, read the next point.

    • This time be very careful! Tighten the zip tie slightly or you will damage the LCD cables! The zip tie should be snug to hold the wires in place. Over tightening it can cut the wires!

    • That's it! Cables are organized, let's connect them to the EINSY board. Now you can turn the printer back on its feet.

    I think is the only spot where the risk to damage the ribbon cable is real. The zip tie is pushing directly against the ribbon in a corner. I took a piece of shrink-wrap, cut it along the side and used it as a protective barrier between the zip tie, ribbons, and around the outer corner. A small piece (3cm) of textile wrap here would be perfect.

    Yuri D'Elia - Reply

    Agreed. I printed a short, flat cable anchor to keep the bundle off the table (https://www.thingiverse.com/thing:341067...).

    TickTock - Reply

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

    • Extruder-cable-clip (1x)

    • Heatbed-cable-clip (1x)

    • M3x10 screw (4x)

    • Note the difference between both clips.

    I’ve double and triple checked, no extruder-cable-clip included with my MK3 kit.

    I’ve ended up printing another one with my old 3D printer. Not a single screw or nut was missing, but this part got MIA :P

    Emmanuel Blot - Reply

    I didn’t get one either.

    elpidio - Reply

    Hello, thanks that you have contacted us by email, we will send you the missing parts.

    Martin L. - Official Prusa CS -

    I didn’t receive the cable clips either.

    Al G - Reply

    Hello Al :)

    I’m sorry to hear that, please contact us via our livechat or e-mail to info@prusa3d.com, so we can arrange for the missing clips to be shipped to you.

    Marcin M. - Official Prusa CS -

  24. Insert the heatbed cable bundle including the textile sleeve in the Einsy-base. Make sure the sleeve is inside the holder, see the picture.
    • Insert the heatbed cable bundle including the textile sleeve in the Einsy-base.

    • Make sure the sleeve is inside the holder, see the picture.

    • Use the Heatbed-cable-clip and two M3x10 screws to fix the cable bundle in place. Note the correct orientation of the clip, try closing the door.

    I have just run into my first missing parts problem (so close to the finish line). Although I have a kit with a textile sleeve for the heatbed cable bundle, I don’t have a cable clip. I have checked  through everything I have left (which is not much) a couple of times and there are definitely no clips. I don't have the means to print one for myself because my old printer is no longer operational. How can I obtain one?  In the meantime can I carry on with the connections and add the clip later?

    David Day - Reply

    I also had the problem of both these clips (also extruder cable clip) being missing, I realise it was not in the bundle of files to print before starting assembly. I just drilled two 3mm holes in the area where the clip would attach and used a cable tie.

    Werner Marais -

    I had an issue with this part as well. The heatbed-cable-clip is a bit to thick (the side that goes inside the door part). Although everything is fitted quite nicely, the door would not close. After cutting away approx. 2mm, the door closes now and can be shut with the 40mm screw.

    Pablo - Reply

    When zooming the second photo the first one is shown.

    Ybl84f1 - Reply

    Hey Ybl,

    I’ve checked it and it’s working as intended. Are you sure you clicked on the right picture?

    Official Prusa Support

    Filip M - Official Prusa CS -

    This orientation of the clip is obvious in the online photo, the printed manual with tiny photos and poor contrast leads to the distinct possibility of fitting the clamp rotated by 180 degrees and not being able to close the door

    Martin - Reply

  25. IMPORTANT: it is CRUCIAL to connect the PSU and HB cables in correct order to the EINSY board. POSITIVE WIRE must be connected to POSITIVE SLOT. There are TWO VERSIONS of the cables with different coloring system: Version A: both wires on each pair are black, POSITIVE WIRE is  marked with a RED LINE
    • IMPORTANT: it is CRUCIAL to connect the PSU and HB cables in correct order to the EINSY board. POSITIVE WIRE must be connected to POSITIVE SLOT. There are TWO VERSIONS of the cables with different coloring system:

    • Version A: both wires on each pair are black, POSITIVE WIRE is marked with a RED LINE

    • Version B: on each pair, there is a red and black wire. POSITIVE WIRE is FULLY RED.

    • Connect wires from PSU and HEATBED to the EINSY board in the following order (red arrows indicate positive slot):

    • The first cable from the PSU (A+|A-).

    • The second cable from the PSU (B+|B-).

    • Cable from the heatbed (C+|C-).

    • Both cables (two pairs) from the PSU are the same, their order doesn't matter, just ensure correct polarity.

    The wires on the PSU and HB that I received are actually black and red with a black stripe. I’m reasonable sure the red wire is still positive but this might be confusing to other people.

    Kurt Stutsman - Reply

    same for me, in general mostly red with a black stripe can mean hot wire, along with mostly black with a red stripe meaning ground

    must have been a recent revision that hasn’t made it to the guide

    joe kitchin - Reply

    Who thought anyone could make something as simple as “plus” and “minus” so complicated??? My positive PSU wire is half red, half black with a thin red stripe in the black!!! Who in their right mind makes a positive lead half black? Hey McFly…

    Ybl84f1 - Reply

    I agree! Why not make positive ALL red and negative ALL black?

    Laurie Bunch -

    I think it would be a bit easier to connet the PSU and HB wires to the EINSY board without the door mounted to the frame. Maybe move the steps for mounting the door after the PSU and HB wires are connected.

    Just a thought.

    Eddy Gleason - Reply

    Eddy Gleason is correct, especially if you’re right-handed. Loosen the screws holding the case to the frame and slide it off. Connect the power cables, then slide it back on and tighten the screws. Much easier than fighting the cables while the case is fixed to the frame.

    Tony Morgan - Reply

    Chiming in on the confusion, I have red/black wires so it’s pretty clear which side is positive. However, due to poor extruder control or the way the wires split, my black wire has a stripe of red (from the other side) and the red wire has a stripe of black (from the other side) so that’s nice. I hope I don’t start a fire.

    Suggestion for the Prusa team: use black and red crimps for clarity.

    Scott Sullivan - Reply

    Chiming in on this one - please use cables + crimps that are only black and only red. Since this is the step that involves power - it is extremely clumsy that this is not 100% clear. Farnell, Mouser, Digikey & TME will all have the required cable…

    jenschr@gmail.com - Reply

    Concure with the all red or all black wires as the half colors and stripes are unclear. Colored crimps would also be a serious improvement.

    Neil - Reply

  26. Please make sure you have connected  POSITIVE and NEGATIVE polarity as described in the previous step! Always place the wire with POSITIVE polarity in the positive  slot on EINSY. See the pictures for red arrows. Check once more following setup: Take the first cable from the PSU and connect the pair of wires to the  EINSY board. Use the bundled Philips screwdriver. TIGHTEN the screw firmly!
    • Please make sure you have connected POSITIVE and NEGATIVE polarity as described in the previous step! Always place the wire with POSITIVE polarity in the positive slot on EINSY. See the pictures for red arrows.

    • Check once more following setup:

    • Take the first cable from the PSU and connect the pair of wires to the EINSY board. Use the bundled Philips screwdriver. TIGHTEN the screw firmly!

    • Take the second cable from the PSU and connect the pair of wires to the EINSY board.

    • The last pair of wires is from the heatbed. Connect them to the last two slots.

    • Please note that not following these steps correctly could possibly void the warranty on the printer if any damage occurs. Please take your time and double check the correct connections and tighten the screws.

    does it matter which pair of red/black PSU cables go on which PAIR of screws? Can’t tell the pairs apart

    Bobby Coker - Reply

    Yes, this is important, luckily you just need to follow the 3 photos one by one to get the cables in the right order.

    Martin L. - Official Prusa CS -

    ignore the answer from @Martin L. The two pairs from the PSU have no “first” or “second” pair. It’s just confusing wording in the main text. You can put them on either the A or B connection, but be 100% sure that you don’t mix Plus and Minus.

    jenschr@gmail.com -

    Hello there, you are partially right. What ment by my comment is that the + and - cable of the same pair have to be next to each other, as shown on the photos. The order of the PSU pairs does not matter (as clearly stated in the previous step), however, the heatbed power cable shall be at the right-most position.

    Martin L. - Official Prusa CS -

    Disagree with Martin here, see the info bullet in step 25: “Both cables (two pairs) from the PSU are the same, their order doesn't matter, just ensure correct polarity. “

    Markus Imhof - Reply

    Something for Prusa to be aware of; my heat bed has ring terminals on the wires which doesn’t fit the EINSY board without trimming the width of the terminals. The PSU has spade terminals like the photos which fitted fine.

    Luke Carmichael - Reply

    Hey Luke, the ends with ring terminals should be used on the heatbed side.

    Filip M - Official Prusa CS -

    This is confusing - I see someone tried to address that above, but was given another confusing answer. There doesn’t appear to be a way to tell “the first wire from the PSU” and the “second wire from the PSU” so, I assume they are the same, as long as the polarity is kept.

    Evan Fort - Reply

    Hey Evan, please make sure you read the manual carefully when installing the PSU wires:

    “Both cables (two pairs) from the PSU are the same, their order doesn't matter, just ensure correct polarity. “

    Filip M - Official Prusa CS -

    It is a bit confusing when describing the two PSU *power lead pairs* versus the two wires (plus and minus) within each pair. Either PSU PAIR (a plus and minus) can be used on the first set of connectors, the remaining PSU pair used on the second pair of connectors HOWEVER within each pair the polarity is critical. So pick EITHER PSU pair (a plus and minus) when starting but ensure you get the polarity correct. Then take the remaining PSU pair and screw into the second pair of connectors again making sure the polarity is correct.

    Ybl84f1 - Reply

    The provided phillips screwdriver is not the correct one for the terminal screws.

    These require a PH2 or a flat head for proper tightening.

    Ami Levin - Reply

    Hi Ami,

    The supplied screwdriver can be used to tighten the terminal screws.

    Official Prusa Support

    Filip M - Official Prusa CS -

    As many others already noted, the positive cable is half red and half black, while the negative one is almost completely black with a veery tiny stripe of red. Might be confusing for some. The one with more red is the positive, though!

    Also, to make it even clearer it might be interesting to add a photo from the other side. For me, the red stripe was perfectly visible from the other side, meaning on a photo you would see (left to right) black-red-black-red-black-red cables. This is already written well to ensure one does pay attention, but another point of view might be even better.

    Lea T - Reply

  27. Identify all motors using the yellow labels and connect them to the board. X-axis motor (already connected)
    • Identify all motors using the yellow labels and connect them to the board.

    • X-axis motor (already connected)

    • Y-axis motor

    • Z-axis motors ( the order doesn't matter)

    • Make sure the lowest connector is free (marked red). The Z axis motors have to be connected at the same level!! It is a common mistake to connect the Z-axis motors under each other.

    • Try to achieve the similar cable arrangement inside the cover to give yourself enough space to work with.

  28. Find the twisted pair (black and white | PP) cable from PSU and connected it to the board. Press the black&white cable to the left side of the cover. Arrange the cables as in the picture, so you have more space for the upcoming ones. Take the thermistor (green label | HT) from the heatbed and connect it.
    • Find the twisted pair (black and white | PP) cable from PSU and connected it to the board.

    • Press the black&white cable to the left side of the cover. Arrange the cables as in the picture, so you have more space for the upcoming ones.

    • Take the thermistor (green label | HT) from the heatbed and connect it.

    • Thermistor cable can be also in white color and missing the green label. It's polarity doesn't matter, it can be plugged both ways.

    • Try to achieve the similar cable arrangement inside the cover to give yourself enough space to work with.

    My thermistor is just labelled “H” not “HT”

    Alfie Day - Reply

    My black and white twisted cable was not long enough to go up and then back down like in the picture. I don't suppose it matters though.

    Brad - Reply

    Mine also, assuming it doesn’t matter as long as you have clearance for the upcoming wires.

    Ybl84f1 -

    I have way too much x, y, z motor cable…

    Scott Sullivan - Reply

    Minor nit - “Find the twisted pair (black and white | PP) cable from PSU and connected it to the board “ should read “Find the twisted pair (black and white | PP) cable from PSU and connect it to the board”. A REALLY minor nit in an otherwise spectacularly well-translated assembly manual!

    Frank Paynter - Reply

  29. Find the slot for the NYLON filament, you will need it in the next step.
    • Find the slot for the NYLON filament, you will need it in the next step.

    • Slightly separate the nylon from the rest of the cables. No need to unwrap the sleeve.

    • If the nylon is hidden inside the textile sleeve, use the technique in the next step to reach it.

    My nylon filament wasn’t long enough. It didn’t poke out of the cable bundle.

    Zachary Klein - Reply

    Hey Zachary, please measure the filament. If it’s not long enough (50cm) you can always contact our customer support and request a replacement.

    Official Prusa Support

    Filip M - Official Prusa CS -

    My nylon filament also is not long enough.

    James Lathrop - Reply

    Hey James,

    Is your filament below 50cm? If it’s not long enough, then you can contact our support for replacement.

    Official Prusa Support

    Filip M - Official Prusa CS -

    Mine wasn’t long enough either, just connected the cables

    David Lindemann - Reply

    Once you execute next step (30) you will find out that the filament wasn't too short, after twisting the textile sleeve.

    Andres Hurtis - Reply

    Hello Andres

    That is correct, we are actually getting many customers with this “issue” of nylon filament being too short, when in reality it’s fine once you twist the sleeve. We will look into implementing that information in this step :)

    Official Prusa Support

    Marcin M. - Official Prusa CS -

  30. Before we proceed further, we need to twist the textile sleeve. This will prevent the cables inside to slip out during the print.
    • Before we proceed further, we need to twist the textile sleeve. This will prevent the cables inside to slip out during the print.

    • Using your fingers gently twist the sleeve (not the cables) and create several wraps.

    • Twisting the sleeve will effectively shorten its length. In the next steps you might need to twist the sleeve slightly back to prolong it.

  31. Slide the NYLON filament in the hole. Make sure the filament isn't pushing into the motor cables, which would indicate it is too long and you need to slightly unwrap the sleeve and push the filament back. Slide the sleeve in the holder at least 3/4 of the holder's height.
    • Slide the NYLON filament in the hole.

    • Make sure the filament isn't pushing into the motor cables, which would indicate it is too long and you need to slightly unwrap the sleeve and push the filament back.

    • Slide the sleeve in the holder at least 3/4 of the holder's height.

    • Again, ensure the filament isn't pushing the motor cables and if needed slightly unwrap the sleeve and push the filament up.

    • Use the Extruder-cable-clip and two M3x10 screws to fix the cable bundle in place.

    Filimant hole require drilling as the filiment would not even start into hole. Considering the problems I had with the filiment, I wonder if I got a piece that was over size?

    Jerry Vaughn - Reply

    Hi Jerry, the hole is designed with filament tolerance in mind, but it might be possible it is slightly smaller and the nylon bigger than usual. Carefully widen the hole or contact our support.

    Jakub Dolezal -

    Same issue, nylon filament measures Ø3.3mm, instructions said it should be Ø3mm. Forcing will undoubtedly break plastic printed part.

    Joe Morton - Reply

    Same here, just measured mine and it’s also 3.3mm.

    Dan M -

    Hi,

    You can always trim the end a bit using pliers, cutters or exacto knife.

    Official Prusa Support

    Filip M - Official Prusa CS -

    Should list x2 M3nS nuts on this section for the M3x10 screws to grab onto.

    Brandon Boucher - Reply

    Hey Brandon, those are listed few steps before this one.

    Filip M - Official Prusa CS -

    Filip Misiło  - Actually it isn’t. I was wondering about this as well. But I could not find any Step that listed adding the x2 M3nS nuts to the Extruder-cable-clip before attaching to the RAMBo-cover-base.

    botanicalyn@gmail.com - Reply

    I had issues getting the sleeve and filament in to position that wasn’t too far in for the filament or sleeve to far out, or the corner of the outer wrap of sleeve sticking out of the clip.

    I put a temporary zip tie around the sleeved cable bundle where it would be 2-3mm above the Extruder-cable-clip when installed. This gave something positive to grip and manipulate the cable assembly in to position and preventing it from unwinding from the end

    Kadah - Reply

    Thanks for this - the temporary zip tie worked really well for me to get everything seated and put together.

    Liquidlogic -

    Same here. Very nice tip. With the zip tie it was a breeze to install. Thanks

    Patrick Leyman -

    Consider a more visible color for the nylon filament. Black is a bit difficult to see.

    Onarian - Reply

    I had the same issue fitting the nylon filament into the hole. I just trimmed a piece into a point and it made sliding the filament in much easier. However, I could not manage to get the wires and the sleeve to be in the holder. I had to peel the sleeve back to be able to secure the holder around the wires.

    Colton Kemp - Reply

    Get the clip FULLY seated before tightening the bolts. I snapped the clip during initial attempt. Fortunately, was easy to weld back together with a low temperature soldering pencil. Will print a new one later, but the repaired clip worked fine once the entire cable assembly and clip were fully seated before tightening the bolts.

    Guy Kuo - Reply

    Impossible to fit the clip with the sleeve inside

    David Lindemann - Reply

    Tightening the extruder cable clip around the sleeved cable is a complete pain. Two things that made it easier and allowed me to close it up 100% without feeling that I was going to snap a part: 1. gently twist the sleeve to pull it out of the gap between the clips while tightening. The sleeve gets compressed in this gap and makes closure impossible. That worked great on the first side. 2. when twisting the sleeve wasn’t enough on the second side of the closure, I poked a shim (thin nail file in this case) down the hole to push the sleeve out of the gap. After that, closing up the extruder cable clip was a breeze.

    It also helps to have the sleeve twisted tight around the cable bundle before you start. This bundle needs to be as compact as possible before closing the clip.

    Scott Sullivan - Reply

    I encountered three bad M3x10 screws during assembly. The threads were damaged out of the bags making this step very difficult until I figured out the threads were bad. You could tell something was amiss when screwing in the two screws for extruder-cable-clip. When initially pushed together, there was no seam but as I turned the screws, a seam appeared and widened. I replaced the two screws and the cable clip went together seamlessly. I tested the screws, all three would not thread into nuts. Be on the lookout folks, probably a good idea to test the screws into nuts at each step.

    Joseph Christopher Wolf - Reply

    Screw it , literally. I swapped in some longer bolts and blew them out the back side. The ones listed were never going to engage the nuts with that cable group in them.

    MileHigh3Der - Reply

    I ended up short 1 M3x10 screw ….even considering the spares bag. Had to cut a longer screw from the spares. I have been very careful with my fasteners and am confident I did not lose any. Also, my filament was too long by approx 20mm. I can only hope that it did not somehow pull out of the print carriage assembly on the other end…. I doubt it as I have been exceeding careful. Even the picture shown in step 31 seems to show that their filament will be too long. I was able to angle it between the X and Y axis connectors in the controls box. I I think it is important to note that the filament does not go straight down into its hole. It is at an angle. Some of those who are having to ream out their holes, maybe are just trying to insert at the wrong angle.

    Todd Podbielski - Reply

    Hello Todd, thanks for your remarks, we’ll pass it to the packing department to make sure everyone will have enough screws.

    Martin L. - Official Prusa CS -

    Just out of curiosity, what is the purpose of the nylon filament? I think I have mine in, but not completely happy with it and the cable layout in the textile sleeve, but I think it is ok.

    Randy Blackwood - Reply

    Hey Randy,

    It’s supposed to support the extruder cable bundle.

    Filip M - Official Prusa CS -

    This particular step was my Waterloo on this project - I could not get the clip to close well enough to engage the 10mm screws. After (literally) hours of work, I wound up shortening an 18mm screw down to ~15mm to use as an engagement helper, and then used 2ea 3x12 flathead screws from the spares package to finish the job. I also had to snip off as much sleeve material as possible to finally get the thing to close.

    Frank Paynter - Reply

    This was the hardest part of the build so far. I ended up using one end of the pliers in the hole that the square nut goes and the other by the screw head and squeezing it tight. Took about fifteen minutes to finish, but got it. It’s very tight, but doable.

    Keith Wilson - Reply

    Thank you, Keith W. After futzing with this for about an hour I tried your method and had it done in 5 minutes.

    Lane Hauck - Reply

    not sure what was worse this or attaching the nylon end to the hotend.

    ajacks - Reply

  32. IMPORTANT: Connecting the filament sensor cable properly is crucial. If you don't follow the instructions properly, you will burn the sensor!!! DON'T CONNECT THE CABLE NOW , wait for the next step!!! Note, there are two rows of pins in the connector, FOLLOW the instruction in the next step to use the correct row!!!
    • IMPORTANT: Connecting the filament sensor cable properly is crucial. If you don't follow the instructions properly, you will burn the sensor!!!

    • DON'T CONNECT THE CABLE NOW , wait for the next step!!!

    • Note, there are two rows of pins in the connector, FOLLOW the instruction in the next step to use the correct row!!!

    • To ensure the cable is connected properly we are introducing a new part called "plug-aligner", which is now distributed with all MK3 printers leaving the factory.

    • In case the plug-aligner falls out during the transport, gently push it back in. The notch should be oriented up, like in the picture.

    • The last picture is showing, how to plug the cable with the plug-aligner present, but wait for the next step ;)

    • STL file for the plug-aligner will be soon available in the MK3 package at prusa3d.com/prusa-i3-printable-parts/

    My MK3 kit arrived 2 days ago and I had no plug-aligner in it. Must be a new entry…

    repcsi - Reply

    That step was added in advance. You can always print the part yourself once it’s released.

    Official Prusa Support

    Filip M - Official Prusa CS -

    Yhea i have just got to this step my self and this part is missing also, looks like it will be my first print after getting it all calibrated

    Dean - Reply

    Hey Dean,

    That step was added in advance. You can always print the part yourself once it’s released.

    Official Prusa Support

    Filip M - Official Prusa CS -

    But isn't the purpose of the part just to align the cable when hooking it up? I mean I guess it makes sense if you need to take it apart again in the future, but once it's assembled what's the point in printing it out? I mean I've never used a 3D printer and don't have access to one so there would be no way for me to print this until the entire thing was assembled and at that point it seems moot

    Bill the Cat -

    Hey Bill,

    Correct, the part is mainly intended for “fresh” assembly. But I suppose it won’t hurt to add it later if you ever need to re-connect the sensor to the RAMBo board.

    Official Prusa support

    Filip M - Official Prusa CS -

    My kit also didn’t have the aligner. (Can’t print it before you get the printer assembled if this is your first printer)

    The filament detector cable goes on the BOTTOM pins of the socket. Although the picts for this step don’t show the pins, you can look at pict in NEXT step to see how the connector goes without the aligner.

    Mistakes to avoid are wrong row of pins, upside down connector or having it one pin left/right of center.

    Guy Kuo - Reply

    May be worth mentioning that even with the orange plug aligner there are still two rows and one must still pay attention to which row is used. Despite all of the warnings, with the existence of the aligner I only paid attention to getting the wire colors correctly oriented and still managed to plug the thing into the wrong row. Luckily this was detected during calibration and I was able to easily fix.

    Jeremy Volkman - Reply

    Hey Jeremy, it’s actually mentioned a few times in the assembly manual - make sure to follow all pictures and descriptions closely.

    Official Prusa Support

    Filip M - Official Prusa CS -

    Why not make the plug aligner with a filler so that you can only plug into the bottom row?? (I made the same mistake and connected to the top row as I assumed that the aligner prevented plugging into the top row :-/

    Cheers!

    Dennis Vaders - Reply

    Hi Dennis! It’s because the other row is where you plug the MMU data cable if you have the MMU.

    Martin L. - Official Prusa CS -

  33. Connect the remaining cables from the Extruder: Extruder heater (red cable pair | Nr. 1) Left hotend fan (black cable | Nr .2)
    • Connect the remaining cables from the Extruder:

    • Extruder heater (red cable pair | Nr. 1)

    • Left hotend fan (black cable | Nr .2)

    • Front print fan (red label | Nr. 3)

    • Filament sensor cable (USE THE LOWER ROW of pins in the connector and ensure the red wire is on the right, facing the outside of the board | Nr. 4). Double check the connector fits to all pins on the board!!! Misaligning the connector can damage the sensor!'''

    • Extruder motor (yellow label with "E" | Nr. 5)

    • Extruder thermistor (green/yellow label | Nr. 6)

    • P.I.N.D.A. probe cable (Nr. 7)

    Labeling or colo coded bands on all the wires would make ID’ing a log simpler. I got them right but checked them 5-6 times too make sure.

    Jerry Vaughn - Reply

    Hi Jerry, most of the cables are labelled. Which cables you had issues with?

    Jakub Dolezal -

    My P.I.N.D.A cable only has 3 cable (black, blue and brown) but my board has 4 male pins. (Nr. 7). can you please advice?

    Erick - Reply

    Thank you for notifying us! One of our packers mixed two boxes together. Please send us a photo of your PINDA probe to info@prusa3d.com and we will arrange a replacement for you at once.

    Martin L. - Official Prusa CS -

    They sent the wrong cable to my printer (AHHH!! <— Me being frustrated. Now I need to re-work the wiring and also the P.I.N.D.A sensor once they ship the new wire. Not sure if all this time is worth it the time for this price tag. Support was not very good, just not very happy with this purchase.

    Erick - Reply

    Hi Erick! We’re sorry for accidentally sending you a wrong PINDA. One of our packers mixed two boxes together. Being still a relatively small company, we are handling hundreds of orders every day, so mistakes happen, unfortunately.

    Should anyone else have a similar problem, do not hesitate to contact us on Live chat or email (info@prusa3d.com), we will do our best to help you!

    Martin L. - Official Prusa CS -

    I don’t know if this is a more recent issue due to your increased order load, but I also have a three wire female connector on the end of my P.I.N.D.A. probe. I purchased my i3 kit in July 2018 and have been chipping away at it slowly and found this issue last night. I will try to talk to your customer service live chat to see if it can be resolved soon.

    Nate - Reply

    My pinda probe loop, back at the probe, is a bit too big! Not enough length in the box to reach the female socket.

    What a pita it will be to go all the way back to shorten the loop.

    Can you simply send me a short extension!

    Bob Hayssen - Reply

    My kit had the plug aligner inserted in the socket for the filament sensor. I’m kicking myself for this, but I got the idea that the aligner does ALL the thinking for me. i.e. does not let me use the wrong pins. Actually it only prevents side-to-side errors. You still have to use the bottom set of pins. It says that in the documentation of course, but the photo does not have the aligner part shown, and I thought that was out of date. I inserted the connector without a care in the world, thinking it could only enter in the correct position, only to have filament sensor wiring error during self test. Easily fixed by connecting to the bottom row of pins, and gratefully does not harm the sensor.

    Anyway the self test now passes and I’m printing Triceratops. Yippee !

    elpidio - Reply

    Same issue with PINDA cable it was a tad short due to my loop being a little big. With a little effort I was able to stretch the cable to make it to the connector.

    Randy Blackwood - Reply

    I also had a problem with the PINDA cable being a bit too short, and was also able to stretch it just enough to make the connection (without, I hope, damaging the cable). Strongly suggest increasing the length of this cable just a little bit.

    Ron Nunn - Reply

    Hey Ron,

    All PINDA cables are cut to same length. Make sure you do a proper loop during extruder assembly, otherwise you won’t have enough of the cable to connect it.

    Filip M - Official Prusa CS -

    i also had problem with the cable length of the pinda probe.

    but the issue is not the cable length itself, it has to do with that you are asked to make a loop of it near the extruder and if this loop is too big then there wont be enough left compare to the rest of the cables.

    and this you only find out much later and then have to cut the zip ties and pull some more thru.

    i my case i had struggled alot to get the cable bundle screwed in to the box (step 31) only to find out i needed to remove the clip again.

    Torbjörn - Reply

    Save yourself a whole lot of future grief by double checking the wire colors on the Filament Sensor Cable. The photo in the circle shows the correct colors (Red, Black, Blue, White, Empty). My cable was wrong making it seem that my sensor was bad. They sent me a new sensor and cable. I only replaced the sensor as I had checked the cable for shorts and opens and redoing the cable harness to the print head looked like a pain. Fortunately I noticed the new cable did not match the old cable before turning on the power or I may have killed the replacement sensor as well. My bad cable had red and black swapped at the EINSY end.

    Doug Butler - Reply

  34. LCD cable with ONE stripe (Connector P1) LCD cable with TWO stripes (Connector P2) The pink stripe on the LCD cables should be facing upwards.
    • LCD cable with ONE stripe (Connector P1)

    • LCD cable with TWO stripes (Connector P2)

    • The pink stripe on the LCD cables should be facing upwards.

    • Note in case of the daughterboard the cables are connected in the same order and orientation (see the second picture).

    • Try to achieve the similar cable arrangement inside the cover.

    “Try to achieve the similar cable arrangement inside the cover.”

    Adam Timmerberg - Reply

    I was confused for a while, please put a picture with the black stamped stripes zoomed in?

    Christopher Rouxel -

    Hey Christopher,

    You can zoom in on all the pictures, just click on them or the magnifying glass in the corner of the picture.

    Filip M - Official Prusa CS -

    Is there a concern with heat dissipation on the back of the board, could the LCD wires go behind the board without causing damage?

    Russell Peake - Reply

    Hey Russel, it’s recommended to keep all the cables as the manual says.

    Filip M - Official Prusa CS -

    Hey Filip, i’ve not altered my cables - my question was more one of working out if there is a better way to guide users to connect the cables beyond “shove them in and try to make it look like the picture.” The Cables that are not in the Gantry bundle could easily be routed and connected prior to attaching the einsy box to the frame (and would probably be easier to do so due to space) - adding the LCD behind the PCB would - if there was no heat concerns - clear up the front even more for attaching, and maintaining the cables from the gantry and heat bed.

    Russell Peake -

    I’m sure there are more ways to lead the cables, but in the end it’s not an ideal solution - sometimes you might need to remove those cables, and it could be too much hassle to get them from behind the RAMBo.

    Filip M - Official Prusa CS -

    With a ‘try to get the same arrangement as we have’ approach it is almost guaranteed to be a hassle to get to any cable - as they aren’t placed in any set arrangement. I feel order of operations, and cable management is where the prusa starts to loose its elegance - up until the wiring of the x/y/LCD cables the printer feels slick and well planed… then the control board goes on and it’s so ‘just throw it all in there’

    If there is a good reason to need to remove the LCD cables frequently - then having a rear access panel would be useful (would mean octoprint wouldn’t need to tear down so much of the build) - otherwise the odd requirement to need to remove the electronics (with an elegant layout) wouldn’t be an issue.

    Russell Peake -

    I ended up with a fair amount of slack on the LCD cables and routed it behind the power cables and flat against the controller side of the case, then up along the outer edge of the case, behind the bed cables, and finally folded over and in to the headers.

    Like this: https://i.imgur.com/WdQJrmL.jpg

    Kadah - Reply

  35. Check your electronics connection with the attached picture. Make sure once more the Filament sensor cable is connected to all pins! Misalignment might lead to permanently damaging the sensor.
    • Check your electronics connection with the attached picture.

    • Make sure once more the Filament sensor cable is connected to all pins! Misalignment might lead to permanently damaging the sensor.

    On my build there is a clear brown plastic disc affixed to the raspberry pi header should i remove this? what is it for? it seems to be stuck on pretty good

    Will - Reply

    Hey Will,

    There is no need to remove it. It’s covering RPi zero pin slots.

    Filip M - Official Prusa CS -

  36. M3x40 screw (1x) Close the Einsy-door.
    • M3x40 screw (1x)

    • Close the Einsy-door.

    • Make sure that no wire is pinched!

    • Tighten the M3x40 screw.

    More instruction here would have been helpful. I was not sure if I was supposed to scrunch all the wires into Einsy box before closing. (I brought in my wiring expert).

    Also, the door would not close due to the 1/2 circular part of the door that seems to need to fit inside the door. However that part of my box forced the door to move outward and the side of the box to move inward loosing the alignment of the two holes for the long screw. (needless to say I am not an engineer) I consulted the expert mentioned above and with his help, trimmed enough of the surface of the 1/2 circular part to align the two holes for the screw.

    botanicalyn@gmail.com - Reply

    I had the same problem with closing the door. Its obviously the old design of the door (you can see it in the photos above). Will there be a plan available to print the proper door? I am using clippers to hack out the door, but it would be nice to get the proper door for this design….

    I enjoyed putting this together. I learned a lot that I will be taking into my next project, and confirmed some of my designs.

    Wyvernn -

    Hi Wyvernn,

    If you wish to re-print the door, then you can find the printable parts here: https://www.prusa3d.com/prusa-i3-printab...

    Filip M - Official Prusa CS -

    Quite a bit of wiring and LCD cables hanging below the box. Zip tie into a bundle? And just let them hang there?

    Bob Hayssen - Reply

    Hey Bob, you can just let them hang there. There’s nothing wrong with that :)

    Filip M - Official Prusa CS -

    What a mess with all those wires, make it bigger, it can. I can’t close that %#*@ door. Make it wider and longer. How hard can it be.

    albert 3d - Reply

    It’s crucial those wires have enough space, but they don’t have, stupid design.

    Sorry Josef,, make it better,

    albert 3d - Reply

    Hello Albert, It is crucial for the cables to be plugged in correctly, don’t be afraid to squish the cables a little while closing the case.

    Martin L. - Official Prusa CS -

  37. If you've assembled the feet in the second chapter, you can skip this step. Antivibration feet (4x)
    • If you've assembled the feet in the second chapter, you can skip this step.

    • Antivibration feet (4x)

    • Turn the frame on it's side and insert the antivibration foot, then rotate with the foot until you squish the rim inside the extrusion.

    • Repeat this process on all 4 feet. Place them 2-3 cm from the end of each extrusion.

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

    • Centre part (1x)

    • Side arm (2x)

    Shouldn’t that say “Side arms (2x)”, not “Side arms (1x)”?

    John Petrangelo - Reply

    Hi John, yes. Already fixed ;)

    Jakub Dolezal -

  39. Don't use excessive force during the assembly, or you might damage the spool holder locking system. Place all three parts in front of you. Note both &quot;arms&quot; are identical. Make sure the C shaped part, which will snap on the printer's frame is facing towards you. Take the &quot;arm&quot; on the right side, insert it gently in the main part and start to rotate clockwise (away from you). It should take about half the turn to lock the part in place.
    • Don't use excessive force during the assembly, or you might damage the spool holder locking system.

    • Place all three parts in front of you. Note both "arms" are identical. Make sure the C shaped part, which will snap on the printer's frame is facing towards you.

    • Take the "arm" on the right side, insert it gently in the main part and start to rotate clockwise (away from you). It should take about half the turn to lock the part in place.

    • Take the "arm" on the left side, insert it gently in the main part and start to rotate anticlockwise (towards you). It should take about half the turn to lock the part in place.

    • The assembly requires a very small force (torque). If you experience issues, check first the locking mechanism for obstacles.

    The outer end stops on the double spool holder arms are too large. There are several filaments on the market with a spool centrum hole of just 20 mm, so they will not fit on this double spool holder. Could you, please, redesign the arms and publish the STL-file on your web site (or anywhere else)?

    Bengt Wannerheim - Reply

    Hey Bengt, unfortunately we can’t cover all the possible spools on the market - but we’ll keep that in mind.

    Filip M - Official Prusa CS -

    On my parts, both arms rotate “clockwise” for assembly (not anticlockwise as described for the left side).

    Bill Spens - Reply

    Mine are not fitting at all… I’ve even try pushing the left arm in it just doesn’t lock in.

    beyafabrice@gmail.com - Reply

    Hello,

    Please check the locking mechanism for obstacles, perhaps there’s something inside.

    Filip M - Official Prusa CS -

    Take the "arm" on the left side, insert it gently in the main part and start to rotate anticlockwise (towards you). It should take about half the turn to lock the part in place.

    should read

    Take the "arm" on the left side, insert it gently in the main part and start to rotate (delete anti )clockwise (towards you). It should take about half the turn to lock the part in place.

    Great instructions and comments section on the online manual are priceless. Keep up the awesome work………taking the world to a better place.

    john@freesuns.com - Reply

    I had trouble getting left side in, and then finally realized I had not turned the right side in enough to provide clearance for the left one. Once I tightened the right one a bit more, the left one went in easy.

    Randy Blackwood - Reply

  40. To properly mount the spool holder, let the &quot;tooth&quot; sit on the frame (in the middle) and then press in the direction of the arrows (push backwards, while slightly pressing downwards). Don't try to assemble spool holder by pushing it only from the top. More force is needed and you may damage the holder. Don't try to assemble spool holder by pushing it only from the top. More force is needed and you may damage the holder.
    • To properly mount the spool holder, let the "tooth" sit on the frame (in the middle) and then press in the direction of the arrows (push backwards, while slightly pressing downwards).

    • Don't try to assemble spool holder by pushing it only from the top. More force is needed and you may damage the holder.

    Mine didn’t seem to fit properly, unlike others it was too loose and would just flex back to the original position. After trying to add a little extra force (and I do mean a very little amount) the bottom tooth snapped with no warning. I’ve jury rigged the holder on with two of the supplied cable ties until a replacement arrives. Hopefully this temporary quick fix will be useful to anyone else itching to get printing only to be foiled at the final step.

    ajcmcwilliam@gmail.com - Reply

    When the extruder head is up in the area of the spool holder bracket, the clearance is pretty tight, maybe a millimeter. No issues, but I’ll be looking at it closely if I ever do a very tall print.

    Matt Laudato - Reply

    Make sure you mount to the back of the frame not the front!

    It works fine until you print something tall and the extruder hits it travelling in X…

    Paul T - Reply

  41. Congratulations, you've just assembled the Original Prusa i3 MK3 3D printer!
    • Congratulations, you've just assembled the Original Prusa i3 MK3 3D printer!

    • You're almost there... Just finish the chapter 9. Preflight check

    Suggestion: Add eat a Haribo to this step

    Adam Timmerberg - Reply

    I would like to see a video of the person who could assemble this printer in 4 hours.

    Bill

    William Wilson - Reply

    I would like to see that as well.

    Scott Sullivan -

    I did it in 3 …

    … days!

    Laurie Bunch -

    This step too me about 1 hour 15 minutes. I’d say 1-1.5 hours is a good range.

    Phil Kelly - Reply

Finish Line

232 other people completed this guide.

Jakub Dolezal

Member since: 02/20/2017

213 Guides authored

Team

Prusa Research Member of Prusa Research

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354 Guides authored

14 Comments

Hate the textile wraps.

Keith Spitz - Reply

great diagrams Jakob. went well for the most part. I am a little concerned about the filament sensor cable connector (5 pin). it doesn’t lock onto the pins very tightly. Mine came loose once while working on the other cables. BTW. did I mention I hate the Textile Wraps?

Doug Kline - Reply

It’s wonderful to know some people hate the textile wraps !?! But wouldn’t it make more sense to know why?

Franziskus - Reply

Very enjoyable build. This is a solid and great looking machine.

Matt Laudato - Reply

Initially I didn’t like the textile wraps ( thought it was difficult to get the wires inside) but when I understood the twisting motion and how this shortened the wrap I came around. My only concern was that when I twisted the wrap to expose the nylon filament it left an uneven end to the wrap. wasn't sure if I should trim off the uneven end to make it more secure inside the extruder cable clip. In the end just put an additional zip tie around the wrap just outside the box.

Craig - Reply

Overall a very enjoyable build. The instructions are very good though you must really pay attention to each step including looking at each photo.

Craig - Reply

suggestions

1. LCD ribbon cable should Not be ran inside the frame channel without retention, having moving parts so close by and no method of retention it’s just a matter of time before the ribbon gets shorted to ground and letting the factory smoke out of the controller. It makes sense to run the LCD ribbon cable Assy along the outside of the frame using snap lock black plastic covers (obviously post assy the end user can print these covers in different colors)

2. Harness from PSU to RAMBo should be ran outside of the frame using snap black covers as well

3. Bed drive belt tensioner should be added and mounted at the Frame “v” on LCD side of frame

4. Extruder drive belt could use 2 idler/tensioner wheels that mount on the back extruder plate that would be retained via the already present 4 plate bolts.

5. Too many zip ties utilized as permanent retention methods (bed/plate guide rods, wiring harness under frame etc

other than that fantastic job on the build, looking forward to my SL1 build!

Randy Davis - Reply

I also found that a 2ft 1/2” brass rod or tubing is ideal to put the textile wrap on first prior to sliding it on the harness, makes installation a breeze

Randy Davis - Reply

Anyone else wish the board faced OUT, so you weren’t bumping your elbow into the PSU while trying to plug all the wires in? I’d love to know why the connectors face in.

Matthew Mackey - Reply

Bedankt, was een plezier om te bouwen. Complimenten voor de zeer duidelijke handleiding.

Ton de Groot - Reply

I like the textile wraps. They look nicer than the cheaper looking plastic ones and I didn’t have any trouble with them.

EchoWhisky - Reply

Great enjoyable build, only needed to shave one part, before realizing I was fitting it back to front duh! Now for the pre flight check…

Lionel Pullum - Reply

1:20 hrs environs. good job. :) shema est bien représenté facile a comprendre. Merci

Joel Daigle - Reply

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