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  1. Needle-nose pliers for the heatbed assembly
    • Needle-nose pliers for the heatbed assembly

    • 2.5mm Allen key for M3 screws

    • 2mm Allen key for heatbed alignment

    aww 4 more steps than the old PSU.

    NightmareOn - Reply

  2. For the following step please prepare: Heatbed MK52 24V (1x)
    • For the following step please prepare:

    • Heatbed MK52 24V (1x)

    • Power cable (1x)

    • M3x10 screw (2x)

    • M3/3,2/9/0,8 washer (2x)

    • M3nN nylock nut (2x)

    • IT IS VERY IMPORTANT to connect the power cable correctly. Before you start the assembly have a look at the pins. The one on the left with "GND" sign must be connected to the BLACK WIRE.

    The instructions fail to specify which of three cables to use, relying on the photo and the bag label.

    The cable needed here is the one with the round bits on one end.

    Lessian - Reply

    Agreed, it should mention it’s the shortest cable of the three, the one with the loops on one end. The bag calls it the “heatbed cable”.

    Vincent Mallet -

    Thanks for your feedback, I will make sure to pass it to my colleagues.

    Martin L. - Official Prusa CS -

    It is also confusing for me since one of the wires is black and the other is red and black.

    Tom Williams - Reply

  3. Place the black wire above the pin with "GND" sign. Make sure you are using the rounded connector. Place the washer above the rounded cable connector. Press the M3x10 screw through all parts.
    • Place the black wire above the pin with "GND" sign. Make sure you are using the rounded connector.

    • Place the washer above the rounded cable connector.

    • Press the M3x10 screw through all parts.

    • Hold the screw and carefully turn the heatbed upside down.

    • Place the M3nN nut on the top of the M3 screw and tighten it slightly.

    • Turn the heatbed back, using pliers and Allen key tighten the screw. We need to adjust cable position in the next step, therefore do not tighten the screw too firmly.

    • Repeat this procedure for the second (red) wire.

    The final step is unclear until you see the next step. You repeat the process for the red wire to attach to the VCC square, not the center opening.

    Jeffrey Foley - Reply

    Hello Jeffrey,

    Thank you for the feedback. Could you please clarify what exactly isn’t clear in this step?

    Marcin M. - Official Prusa CS -

    I think Jeffrey might mean that the photo makes it look like the red wire is connected to the underside of the heatbed.

    Sean Tobin -

    No, no, both cables need to be connected to the top side! Writing in bold so that others would notice :)

    Martin L. - Official Prusa CS -

    This step is unclear for me. In the photo you have a BLACK AND RED wire connecting to the GND terminal and SOLID RED wire connecting to the VCC.

    My wire has a SOLID BLACK and a RED AND BLACK wire!

    I am assuming I connect the solid black wire to the GND and the red and black to the vcc. Confusing because your photo has red and black to GND which would put a solid black on VCC.

    adam - Reply

    Hi Adam, your assumptions are correct.

    Filip M - Official Prusa CS -

    Yes, I also got a fully black and a red/black cable. It became a bit confusing but thanks Adam for the correction

    Javier Ravines -

    If you are going to take on this build then you should be able to tell which wire YOU hooked up to + and which wire YOU hooked up to ground, ON BOTH ENDS. YOU are hooking this up to your heated bed on one end and your Einsy board at the other end. If this is beyond your electrical abilities then, perhaps, you should have ordered the pre built unit

    Lee Kibbler - Reply

    FYI if you want to get a wrench or nut driver instead of using pliers on the nut, it’s 5.5 mm.

    Curtis - Reply

    Clear enough, I suppose, but I feel like this sequence for the first three steps might be more logical: “Place the washer on the m3x10 screw, then the rounded connector, then push the screw through the pin with the GND sign.” At least, that’s the way most folks I know would do it.

    As written I can just imagine someone trying to hold the connector over the hole in the board, balancing the washer on top, then pushing the screw through, possibly dropping the washer a few times as it slides around. :) Just 1 man’s opinion.

    Chris - Reply

  4. Before proceeding further, please check again the cable is connected correctly to the heatbed. BLACK wire must be connected to the "GND" RED wire must be connected to the "VCC"
    • Before proceeding further, please check again the cable is connected correctly to the heatbed.

    • BLACK wire must be connected to the "GND"

    • RED wire must be connected to the "VCC"

    • The cable cover, which will be applied later requires the connectors to be slightly inclined towards each other. Press them gently, but leave a gap between them.

    • Design of your heatbed might slightly differ from the last picture.

    • Now, tighten both screws using the Allen key and the pliers.

    Each of the photos seem to show the metal connectors being flat, inline wit the surface of the heat plate. Mine are both tilted/bent up a bit. Looking at subsequent Steps it looks like they’re supposed to be flat. With them bent up the covers won’t lay flat as indicated in their respective photos.

    I’m going to bend them so they’re flat and just cross my fingers that that’s correct.

    Roger Garrett - Reply

  5. Before you continue with the assembly, find the cable cover in your package. Take a closer look. There are two version:
    • Before you continue with the assembly, find the cable cover in your package. Take a closer look. There are two version:

    • New design with circular holes in the top part. The smaller part has hexagonal holes. Please follow Step 6

    • Old design with hexagonal holes in the top part. The smaller part has circular holes. Please follow Step 14

    Since I’m on a upgrade kit printing my own parts, where can I find this new design version? Both in the download parts package and in the github repository, I can only find stl’s having hexagonal holes in the top part.

    Mikael Edberger - Reply

    Thanks for reporting this, we will see to it.

    Martin L. - Official Prusa CS -

    Hi Mikael, I've reminded our devs to upload the newest design to the GitHub and I will then add it to the printable parts on prusa3d.com

    Jakub Dolezal -

    Did the files for the new version ever get uploaded? I only see the old version in the stl package

    David Miller - Reply

    Hi David, we had a bug in the STL packaging system. Code is rewritten, expect it on site in 24-48 hours max.

    Jakub Dolezal -

    Still not uploaded…. I’m trying to download the new version as well.

    Eric Sloan - Reply

    Hi Eric, we had a bug in the STL packaging system. Code is rewritten, expect it on site in 24-48 hours max.

    Jakub Dolezal -

    Still not uploaded…. Is there anywhere to download the updated file?

    Jameson Bawden - Reply

    Hi Jameson. We are working on it. The latest STL files will be available soon. Thank you for your patience.

    Vojta Z. -

    Still not uploaded… I ripped my Thermistor cable with the old design and dont want that again…

    fever - Reply

    Hi fever.

    Updated STL files are already uploaded. Thank you for your patience.

    Vojta Z. -

    The Github site (https://github.com/prusa3d/Original-Prus...) has the updated STLs as of about the 26th July.

    However; the Prusa i3 printable parts webpage (https://www.prusa3d.com/prusa-i3-printab... ) still only has the older version STL files.

    Jonathan Lin - Reply

    Hello Jonathan,

    Well spotted, we will fix it.

    Martin L. - Official Prusa CS -

    Hi Jonathan,

    please try to re-download the MK3S package again. The new plastic parts should be in the bundle.

    Jakub Dolezal -

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

    • Heatbed MK52 (1x)

    • Textile sleeve 5 x 300 mm (1x)

    • M3n nut (2x)

    • M3nN nyloc nut (1x)*

    • M3x10 screw (3x)

    • Heatbed-cable-cover (2x)

    • *Your bag with fasteners should include three M3nN nyloc nuts. If you are missing one, please use the spare bag.

    Thank you spare bag :)

    Joseph Finan - Reply

    Just a note, the Textile Sleeve is packaged in the tube that contained the steel rods, but the tube does not reference chapter 7 on the label.

    Michael Palmer - Reply

    Hi Michael,

    Thanks for pointing that out, we will look into changing it.

    Marcin M. - Official Prusa CS -

    The textile sleeves are cut with a hot knife that seals the ends of the fabric to keep it from fraying This ends up sort of sticking the ends together. It is a good idea to unwrap each end of the sleeves while still loose in your hands rather than when you are feeding wires through them. This is especially true of the smaller ones.

    Lee Kibbler - Reply

    Typo: “Your bag with fasteners should include three M3nN nyloc nuts”, but this step only lists on nyloc nut.

    thomas king - Reply

    It says:

    Heatbed-cable-cover (2x)

    That’s not quite correct. There are two SEPARATE parts for the Heatbed cable cover, as shown in the previous Step. The (2x) is normally used to indicate that there are two of the SAME thing.

    Roger Garrett - Reply

    Hi Roger.

    We used a single name Heatbed-cable-cover for these two parts Heatbed-cable-cover and Heatbed-cable-cover-clip (orange arrows in the picture). Because the number of points in one step is limited.

    Vojta Z. -

  7. Take the smaller part and insert M3n nuts.
    • Take the smaller part and insert M3n nuts.

    • Use the screw pulling technique.

    • Keep this part for later use (Step 10).

    Be very careful if you are using electric screwdriver for this the force may turn the little piece in your hand and cut yourself. Use a clamp or hand screw this.

    Kelvin Tan - Reply

    Prusa, you guys need to do your tolerances better for these nut holes. I have yet to have a hexagon shaped nut hole that fit easily. I’ve had to hammer them in countless times.

    Jane H - Reply

    Hello Jane,

    The sockets are tight on purpose, the nuts must not rotate inside. It will always be needed to push the nut inside.

    Martin L. - Official Prusa CS -

  8. Place the bigger heatbed-cable-cover next to the heatbed. See the hole, which has to match the one on the heatbed. Now, place the cover on the heatbed and align it. Use the M3x10 and push it through the cover.
    • Place the bigger heatbed-cable-cover next to the heatbed. See the hole, which has to match the one on the heatbed.

    • Now, place the cover on the heatbed and align it.

    • Use the M3x10 and push it through the cover.

  9. Hold the screw with your thumb and flip the heatbed upside down.
    • Hold the screw with your thumb and flip the heatbed upside down.

    • Use M3nN nyloc nut and tighten the screw.

    • Use pliers and Allen key to tighten the nut with the screw.

    Be careful, as I found this part very easy to break by applying too much force.

    Eric B - Reply

    I blew out the plastic with very little force, there appears to be a void inside the plastic. Could I just use a washer on top to continue or is there a clearance issue?

    Tom Barse - Reply

    https://m.imgur.com/gallery/iGTh2Uh

    This was my Saturday afternoon fix, I dont know how closely they monitor these comments, but I'm going with it without much other choice at the moment.

    Tom Barse - Reply

  10. Do not stretch the black thermistor cable, leave some slack under the heatbed, so when the heatbed moves during print, the cable won't get stretched resulting in disconnection from the centre of the heatbed. However, the slack shouldn't be causing the cable to sag down more than few millimetres. Otherwise, the cable might rub against the printer's frame and damage itself! Turn the heatbed upside-down to check this. Guide the black thermistor cable next to the heatbed heater cable and wrap it few times around (see the photo).
    • Do not stretch the black thermistor cable, leave some slack under the heatbed, so when the heatbed moves during print, the cable won't get stretched resulting in disconnection from the centre of the heatbed.

    • However, the slack shouldn't be causing the cable to sag down more than few millimetres. Otherwise, the cable might rub against the printer's frame and damage itself! Turn the heatbed upside-down to check this.

    • Guide the black thermistor cable next to the heatbed heater cable and wrap it few times around (see the photo).

  11. Use the textile sleeve and wrap the cables from the heatbed. Start by wrapping a few centimeters of the sleeve behind the heatbed cover. When the first "wrap" is ready, slide it inside the heatbed cover. Ensure it is at least 5-6 mm.
    • Use the textile sleeve and wrap the cables from the heatbed. Start by wrapping a few centimeters of the sleeve behind the heatbed cover.

    • When the first "wrap" is ready, slide it inside the heatbed cover. Ensure it is at least 5-6 mm.

    • Before you continue with wrapping the sleeve, we need to fix it in the cable cover. Please proceed to the next step.

    “Start by few centimeters of the sleeve behind the heatbed cover“ might be better written as “Start by wrapping a few centimeters of the sleeve behind the heatbed cover.”

    Mark A. Post - Reply

    Hi Mark, good point, description updated. Thanks ;)

    Jakub Dolezal -

  12. Take the smaller cover you have prepared earlier and place it like in the picture. Make sure the thermistor cable is in the middle going through a cutout in the printed part!!! Otherwise, you will pinch and possibly break the cable!!! Hold the cover and flip the heatbed back. Insert two screws M3x10 and tighten them, proceed with caution and tighten both screws equally.
    • Take the smaller cover you have prepared earlier and place it like in the picture.

    • Make sure the thermistor cable is in the middle going through a cutout in the printed part!!! Otherwise, you will pinch and possibly break the cable!!!

    • Hold the cover and flip the heatbed back. Insert two screws M3x10 and tighten them, proceed with caution and tighten both screws equally.

    • Don't tighten the screw completely on one side and then on the other (see the second picture)!

    • Your tightened cover should look like the last picture.

    I think a change is needed here. I assembled my kit 10 days ago, and tried very hard to get this right, the printer worked fine for 80-100 hours of printing, then started throwing MINTEMP or MINTEMP BED errors every time. I tested and both thermistors and heating wires tested fine for resistance. I found that the thermistor wire had shifted as I was tightening the clamp, and it had gotten crimped. I’ve ordered a replacement and for now I’ve taken the small cover off and everything works fine.

    One way to change it would be to make the channel larger, making sure there is no restriction around the thermistor wire.

    However a simpler, and to my mind better change is to simply change the instructions and pictures to NOT route the thermistor wire through this clamp at all, just take it below the clamp, and then into the side of the wrap. You can secure it with a cable tie if you think it is needed. This way it is not possible for the wire to be crimped or broken. That is the way that I’m going to be fix mine.

    Kelly Hickel - Reply

  13. Now, finish wrapping the cable into the textile sleeve.
    • Now, finish wrapping the cable into the textile sleeve.

    • When done, slightly twist the sleeve (not the cables inside). The sleeve will evenly wrap all around the cable bundle.

    • You can skip to Step 21

    I made a small hook from 1.5 mm (.06 inch) aluminum wire, similar to a button hook, for those who remember what that was. I rounded off the tip so it wouldn’t catch on the fabric. It helped to get the sleeve, especially the inner furl, onto the wire bundle.

    Miles Odonnol - Reply

    Suggestion to get the cables into the textile sleeve:

    Use a credit card and slide it along the textile sleeve using your hand to guide the cables. The cables easily slip into the sleeve.

    If you’ve ever had to change a flat bike tire, it’s the same concept.

    Ron - Reply

    Between my arthritis and hand tremors, I simply can’t get these wires into the cable cover. This cover seems designed to push cables out rather than cover them. Is there an alternative to this material for the cover?

    Penjim - Reply

    Hi, the cover can be printed from PETG or ABS. You can use alternative types of sleeve for the cables, though.

    Filip M - Official Prusa CS -

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

    • Heatbed MK52 (1x)

    • Textile sleeve 5 x 300 mm (1x)

    • M3n nut (3x)

    • M3x10 screw (3x)

    • Heatbed-cable-cover (2x)

  15. Insert M3n nuts in the printed part. In case you can't press the M3n nut in, don't use excessive force. Take the M3 bolt and  thread it from the opposite side of the printed part, as you tighten the screw, it will pull the nut in. Be careful not the break the printed part during tightening. In case the power cable is fixed by screws (not soldered) the heatbed-cable-cover slightly differs from the picture, but the following assembly process is identical.
    • Insert M3n nuts in the printed part.

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

    • In case the power cable is fixed by screws (not soldered) the heatbed-cable-cover slightly differs from the picture, but the following assembly process is identical.

    We are missing the Joseph prusa head here!

    Pascal Robert - Reply

    Good point Robert, will be fixed ;)

    Jakub Dolezal -

    I’m having the parts of the “Heatbed-cable-cover“ as shown in step 5, with only two holes in the smallest part, not the model shown here with 3 holes. I assume that the same M3x10mm screw plus a normal M3 nut is used to attach it all to the heatbed board, but more up to date pictures showing the exact parts used would be nice.

    Wilko van den Bergh - Reply

    Hello Wilko, that's correct, please use the part you have received.

    Martin L. - Official Prusa CS -

    We want Joe! We want Joe!

    Wesley Boynton - Reply

  16. Place the heatbed-cable-cover on the heatbed to cover the soldered cables and LED. Tighten the cover to the heatbed using M3x10 screw and Allen key. Be careful not to pinch (break) any wires from the heatbed!
    • Place the heatbed-cable-cover on the heatbed to cover the soldered cables and LED.

    • Tighten the cover to the heatbed using M3x10 screw and Allen key. Be careful not to pinch (break) any wires from the heatbed!

    Recommend taking a look ahead at Step17, when you’ll evaluate the results of this step (Step7).

    Just completed Step 17 and needed to modify the attachment of this headbed-cable-cover. The M3x10 bolt extends too far beyond the nut on the top side and impedes movement of the hotend.

    Comments that I left on Step17: “Looks like an M3x8 bolt would be perfect instead of the M3x10. Thought about a Dremel solution, but ultimately removed the M3x10 bolt, just threaded a spare M3n nut up to the head, then re-inserted through heatbed and into cable-cover. Perfect fit and no need to modify a bolt and no need for Prusa to provide a single M3x8 bolt in the kit.”

    Todd Kanning - Reply

    Thank you for this! Saved me the trouble of having to come back and do it again.

    Frank Pape -

    Thanks, I did the same, not sure if it would be a problem, however just to be sure. Think M3x8 would be enough for here.

    Morris -

    Wow! This is huge. I dremeled mine down flush. I saw the blog post where this scew sticking up caused damage to the heater wire of the extruder during calibration. Love being able to take advantage of these build notes. Prusa has done us a favor in that regard. Thanks.

    Ken.Lotts - Reply

    I put an extra nut on the screw before screwing it in. Now it doesn’t stick out of the other side

    He Who Prints - Reply

    This works brilliantly, thanks!

    David Mann -

    My heat cable connectors were bent at weird angles making it impossible to screw the cover on properly. Friend was able to bend them back into shape without damaging anything, cover fits properly now.

    Lessian - Reply

  17. Do not stretch the black/white thermistor cable, leave some slack under the heatbed, so when the heatbed moves during print, the cable won't get stretched resulting in disconnection from the centre of the heatbed. However, the slack shouldn't be causing the cable to sag down more than few millimetres. Otherwise, the cable might rub against the printer's frame and damage itself! Turn the heatbed upside-down to check this. Guide the black thermistor cable next to the heatbed heater cable and wrap it few times around (see the photo).
    • Do not stretch the black/white thermistor cable, leave some slack under the heatbed, so when the heatbed moves during print, the cable won't get stretched resulting in disconnection from the centre of the heatbed.

    • However, the slack shouldn't be causing the cable to sag down more than few millimetres. Otherwise, the cable might rub against the printer's frame and damage itself! Turn the heatbed upside-down to check this.

    • Guide the black thermistor cable next to the heatbed heater cable and wrap it few times around (see the photo).

    • The thermistor cable is in black or white colour, their functionality is the same.

  18. Use the textile sleeve and wrap the cables from the heatbed. Start by few centimeters of the sleeve behind the heatbed cover. When the first "wrap" is ready, slide it inside the heatbed cover. Ensure it is at least 5-6 mm.
    • Use the textile sleeve and wrap the cables from the heatbed. Start by few centimeters of the sleeve behind the heatbed cover.

    • When the first "wrap" is ready, slide it inside the heatbed cover. Ensure it is at least 5-6 mm.

    • Before you continue with wrapping the sleeve, we need to fix it in the cable cover. Please proceed to the next step.

  19. Place second part of the cover on the top of the  textile sleeve. Make sure the thermistor cable is in the middle going through a cutout in the printed part!!! Otherwise, you will pinch and possibly break the cable!!! Insert two screws M3x10 and tighten them, proceed with caution and tighten both screws equally.
    • Place second part of the cover on the top of the textile sleeve.

    • Make sure the thermistor cable is in the middle going through a cutout in the printed part!!! Otherwise, you will pinch and possibly break the cable!!!

    • Insert two screws M3x10 and tighten them, proceed with caution and tighten both screws equally.

    • Don't tighten the screw completely on one side and then on the other (see the second picture)!

    • Your tightened cover should look like the last picture.

    The first picture in Step 10 doesn’t seem to match my MK3S kit. It also seems to show much more slack in the thermistor cable than in Step 8, which DOES match my kit. I thought I was OK with slack at the completion of Step 8. Now, I’m worried about it.

    john brenner - Reply

    Hi John, Step 10 refers to the cover only - please use Step 8 as a reference to how much slack should be left for the thermistor.

    Filip M - Official Prusa CS -

    the 2nd part of the cover looks so bend on the 3rd picture. also aren’t those screws we used to connect the cable totally dangerous? if you touch them you should have a very bad they (when its running)

    NightmareOn - Reply

    Hi Nightmare,

    Please do not touch any parts of the bed while it’s hot/preheating. The part might look bent, but it won’t affect the functionality.

    Filip M - Official Prusa CS -

    … also aren’t those screws we used to connect the cable totally dangerous?

    The screws connected to the cable are underneath the cover. So there‘s no risk of shorting the connection or electrocuting yourself. But you probably should not touch the heated bed while its hot and running anyway

    Christoph -

    Christoph,

    You are 100% correct.

    Martin L. - Official Prusa CS -

    Well I need to correct my initial reply. The screws that hold the cable connectors are not exposed on the topside of the bed. Underneath they are quite acessible. The screws are missing in the pictures above, but with the mk3s kit they are defintely exposed on the underside….

    Christoph -

    Man, mine looks like the “correct” picture but I can’t help but feeling the channel should be a little bit larger to house the cable cover.

    Also, are we expected to tear up the melted end of the cable cover in order to begin threading the cables through? With the large cable cover from the extruder, the hole was large enough to slip the cable ends through. With this little guy? Not so much. I had to tear it open to start feeding cables in.

    Wesley Boynton - Reply

    Yes Wesley, you do need to tear open the ends of the cable cover (textile sleeve) in order to put the wires inside.

    Michael Nolte -

    I had to apply a ridiculous amount of force to get the two covers to come together. I hope this wont cause any damage to the wires later on.

    Lessian - Reply

    I too was worried about the bent look of the cover, so unscrewed everything and flipped each wire. That made it not fit into the cover at all… and it was still bent. So now I’m putting it back to its original state.

    Darrell - Reply

  20. Now, finish wrapping the cable into the textile sleeve.
    • Now, finish wrapping the cable into the textile sleeve.

    • When done, slightly twist the sleeve (not the cables inside). The sleeve will evenly wrap all around the cable bundle.

    The textile sleeve was difficult to work with. I found it helpful to slide the long end of the allen key inside the sleeve ahead of the wires, pulling up on it to force the sleeve open a little.

    Frank Pape - Reply

    why do i feel like gummy bears now? maybe the last one was too short.

    NightmareOn - Reply

    I find the sleeve to be causing the most pain in the rectum in the entire build…

    Razvan Simionescu - Reply

    This textile sleeve has proven most difficult to work with. Is there an alternative material?

    Penjim - Reply

    Hi, please contact our customer service if you have encountered issues with the assembly.

    For alternative materials you might need to look around electronics stores which carry cable sleeves.

    Filip M - Official Prusa CS -

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

    • M3x14b screw (9x) / M3x12b screw (9x)

    • Due to update in manufacturing process, your kit might come with 12mm screws instead of 14 mm. Functionality remains unchanged.

    • 6x6x3t spacer (9x)

    M3x14b screw (9x) / M3x12b screw (9x)

    should be written as:

    M3x14b screw (9x) OR M3x12b screw (9x)

    The slash ( / ) does not make it clear that it’s one or the other.

    Roger Garrett - Reply

  22. Push the Y-carriage to the front and place the Heatbed behind. Locate a hole in the centre of the Y-carriage. Place one spacer on the top of the hole.
    • Push the Y-carriage to the front and place the Heatbed behind.

    • Locate a hole in the centre of the Y-carriage.

    • Place one spacer on the top of the hole.

    • The exact position of the spacer will be adjusted in the next step.

    the position of this spcer is like an amulet against Y misalignment, or something?

    Nahuel Carou - Reply

    Hello Nahuel,

    Amulet, that is a funny idea. Bu t no, the spacers are needed because the heated bed must not touch the metal Y carriage. It has to heat equally everywhere.

    Martin L. - Official Prusa CS -

    Note the cables and cover are at the Back Left when starting this step. (Because you know someone will miss that)

    Gerard Sharp - Reply

  23. Push the Allen key through the middle hole on the Heatbed and place it above the spacer. Use the Allen key to align all parts. After the alignment insert the M3x12b(14b) screw instead. Tighten the screw just slightly.
    • Push the Allen key through the middle hole on the Heatbed and place it above the spacer. Use the Allen key to align all parts.

    • After the alignment insert the M3x12b(14b) screw instead.

    • Tighten the screw just slightly.

  24. Move to the right side of the heatbed. Place another spacer with the pliers. Push the pliers between the heatbed and the Y-carriage.
    • Move to the right side of the heatbed.

    • Place another spacer with the pliers.

    • Push the pliers between the heatbed and the Y-carriage.

    • Use the Allen key to align the spacer.

    • After the alignment insert the screw instead and tighten it slightly.

    I got to this step and couldnt continue…for some reason the holes in my heatbed do not line up with the holes in my Y-Carriage. In order to try to resolve this i tried screwing other holes first and not the center one, sure enough the 3 on the left and 3 on the right were lined up with each other just fine, but the center 3 are not…i hope this doesnt effect my printing…

    Lucas - Reply

    Hello Lucas,

    This sounds like you have mounted the y-carriage wrong. Check if you have 2 bearings on the left side and 1 bearing on the right side.

    Martin L. - Official Prusa CS -

    Same thing for me. As soon as I skipped the center screw, everything matches up.

    Steven Ngu - Reply

    I had a very hard time using the pliers method for the first few screws, mostly because of the magnetic heatbed grabbing my pliers, so here is what I did:

    1. Set the spacers for the first three center screws on the Y-carriage.

    2. VERY CAREFULLY place the heatbed on to the spacers. If you can get low down enough to see between the Y-carriage and the heatbed, you can eyeball it and align the holes to the spacers. If you shift the spacers, you have to start over.

    3. Put screws down in and slightly tighten

    4. Place the rest of the spacers using the pliers method

    Tom Brooks - Reply

    Hello Tom, That sounds good, thank you for sharing your ideas!

    Martin L. - Official Prusa CS -

    Well, this is probably heretical; but I saw a lot of frustration coming with this step (shaky hands etc). I have a tube of Loctite GO2 Gel glue- kind of a gooey super glue. For each screw hole in the Y carriage, I spread a small amount of glue carefully around the hole, being careful to NOT get any in the threads. I then placed the spacer over the hole, and threaded the screw in. I turned each screw in and out enough to make sure the glue hadn’t lock the screw in. I took my time with each spacer, and when I had them all set, I let it all sit for a few hours. Then, in the morning I took out all the screws, and CAREFULLY placed the heat bed over the spacers (they all lined up!!!). I then dropped the screws in all the holes, and tightened them on the order shown in the next step. This for me was much easier. I suspect the glue may cook off, but there’s not much of it there. And most of the volatiles dry out.

    Penjim - Reply

    Hello Penjim,

    That’s an ingenious solution. While is should not be needed, I think it’s safe.

    Martin L. - Official Prusa CS -

    to speed this along …

    1. with the heat bed off the frame, I took 8 twist ties and pushed them up from underneath the frame through the holes around the edges and corners of the frame; they stood up quite tall. I also took the remainder of 1 cut twist tie, left over from a previous step, and pushed it down through the centre hole of the frame. It too stood up quite tall

    2. I then threaded the spacers by sliding them down the twist ties which were sticking up out of the frame

    3. the sliders were then all resting on the frame, centred exactly over the holes

    4. I placed the heat bed directly down over the frame, threading the twist ties through each corresponding heat bed hole

    5. I then, in sequence, slowly removed each twist tie while at the same time replacing it with a screw that went perfectly thru the spacer and into the frame

    Had I kept more of the left over cut twist ties, and if they were long enough, I would have used them rather than full twist ties as it is easier to remove the tie from the top when done

    Rob Latour - Reply

    I did something similar: I kept all the cut off parts of every cable tie used in the assembly, then threaded them through the holes and the spacers and slowly lowered the heatbed down. Afterwards you can pull the tie out and put the screw in. Quick and easy!

    Jan Albiez -

    Good evening. I had on my y carriage backways but ive realized that upon trying to fix it my bearings are somewhat rusty. Is there anything that could’ve affected it during assembly?

    Douglas - Reply

    And would this affect prints? its just the outside of the bearings that are rusty

    Douglas -

    Hello Douglas,

    Did you receive the bearings in this state? Or is it after some time of usage? If you have received rusty bearings, make sure to contact us, we’ll help you with that.

    Martin L. - Official Prusa CS -

    If you are having trouble getting the screws to thread in it could be from the excess amount of paint used. You need to clean out the threads. This will make a lot of mess, so I recommend doing it prior to installing the carriage, but if you’ve made it here its probably too late for that….

    Here is a a tip to clean out the threads if they are really bad like mine ( I couldn’t get the screws to make it more than a few turns it was so bad). Take one of the extra M3x10 screws and file a bevel into the tip, this will allow the threads to cut through the paint and give a pace for the paint to go to. With this I was able to turn it back and forth and make my way through the holes. The amount of pain that came out is crazy!

    Here is an example of the thread chaser shown on a larger bolt for clarity.

    Thread Chaser

    Chris - Reply

    Masking tape to the rescue. This step was a challenge so masking tape was handy and I placed all the screws in their respective holes on the heat bed held in with masking tape. I then turned over the heat bed and installed each spacer held in with a longish strip of masking tape only one side of the spacer. Once this was done I flipped the bad back over and aligned 2 of the screws and “dropped it” in place raising all of the screws off the bed. I then proceeded to start the thread on the two aligned screws, first removing the masking tape and then started the rest of the screws just a few turns by finger (carefully removing the tape). Once all the screws had a few turns and very loose, I turned the printer over and proceeded to remove all the tape on the spacers. Then I proceeded to tighten the screws in the order prescribed. Much easier than the prescribed pliers method I thought. No spacers or screws went missing… I suggest you add some masking tape to the kit!

    Gianni Mariani - Reply

  25. Using pliers insert spacers and screw into the remaining holes. DON'T fully tighten the screws. After all screws are in place, tighten them in the following order:
    • Using pliers insert spacers and screw into the remaining holes. DON'T fully tighten the screws.

    • After all screws are in place, tighten them in the following order:

    • Center screw

    • First four screws (edges)

    • Last four screws (corners)

    I was able to connect the three screws on the right and left side each, but the middle ones are not lining up correctly. They seem to be about an inch off to the side. Did I perhaps put the Y carriage on incorrectly?

    William Oller - Reply

    Hey William, double check your Y carriage - perhaps you have mounted it other way around (2 bearings should be on the left side)

    Filip M - Official Prusa CS -

    I had the same issue, so out of curiousity I flipped my heated bed upside down and tried it then. It fit perfectly.

    Unfortunately, I too mounted my x-carriage wrong :( *sigh*

    Jane H -

    Yea…. That was it. Thank you very much!

    William Oller - Reply

    I did the same as you. I think a bigg sign with red square should do the trick to not make this mistake. This did make me loose abit of energi Så i am ending it for today. Hope I can get more energy tomorrow to fix this . ;)

    mullcom -

    some of my screws were easier than others and sit below the surface while others took some work to get flush to the bed. Is that normal?

    agregorie - Reply

    Hi,

    It’s going to be OK as long as all screw heads are below the bed surface.

    Filip M - Official Prusa CS -

    I definitely made the same mistake as William — I mounted my Y-carriage backwards (it should be with the two bearings on the LEFT when facing the PRUSA logo) so not all of the screws would align.

    If you made the same mistake, here are the shorthand steps I followed to amend it:

    1. Carefully turn the machine onto its side so that the X-axis idler side and the short extrusions are on the workbench (protecting the X-axis motor assembly, the extruder, and the screen)

    2. Release the two M3x10 bolts holding the belt holders to the center of the Y-carriage (you’ll probably have to release tension on the Y-belt tensioning bolt that holds those two pieces together so that you can access all of the bolts freely)

    3. Let the belt holders, still attached to each other by way of the tensioning bolt, rest slack along the belt.

    4. Turn the whole machine back onto its rubber feet (upright) with the PRUSA logo facing you, and snip the cable ties holding the Y carriage metal rods in place.

    Wesley Boynton - Reply

    5. Remove the whole Y-carriage assembly, flip it around, and replace it with the two bearings on the LEFT this time.

    6. Replace the cable ties holding the Y-carriage rods in place with new ones, remembering to snip the excess short and to match the same orientation for the heads of the cable ties (an inside and upward angle) so that they will be out of the way when the carriage assembly moves

    7. Flip the machine over once more as in step 1, carefully slide the carriage into place beneath the belt holders, and replace the two bolts holding the belt holders to the underside of the Y-carriage.

    8. Re-tension the Y-belt using the tensioning bolt

    9. Take a deep breath. It’s not that bad, easy fix, you’re almost there.

    Wesley Boynton -

    There is paint inside the holes. I’d recommend first doing a run with a M3 tap first.

    Jeroen - Reply

    I had to tap one of the holes before I could insert the screw. I recommend having an M3x0.5 tap on hand to chase threads as needed.

    Jeff Keyzer - Reply

    When tightening the hot bed screws, it’s best to tighten in a pattern to even out pressure applied to the bed.

    Tighten the center screw most of the way. Pick an edge screw (say the right edge) and tighten most of the way down, then select the opposite edge and tighten most of the way. Then the top edge (repeat) and bottom edge (repeat). Then one corner screw (tighten most of the way), then the opposite corner, then the two remaining corner screws.

    Then repeat the entire pattern again, from the center screw, edge screws, corner screws, to apply the last bit of torque.

    This way there’s a reduced chance of a the hot bed being canted, twisted and a screw binding.

    Steven Woodbridge - Reply

    In my kit, there were exactly 9 spacers, and none in the spare, please throw in couple of them in the spare ( I dropped one, likely got it back!)

    Ganesan Doraisamy - Reply

    Hello Ganesan, thanks for your suggestion, I’ll pass it upstream.

    Martin L. - Official Prusa CS -

    My the centre nut on heated bed is raised above the heated bed surface even after tightening which can’t be a good thing as the heated bed goes straight on top. Is it worth trying to make it so that it is level on top?

    Sam Crampton - Reply

    It turned out that not all my screws were the same size and one of them wouldn’t sit correctly. Just tried a different screw in the same hole and it was fine so I grabbed a screw from the spares bag to replace the oversized one.

    Sam Crampton -

    I am missing one spacer. A single solidarity spacer. As noted previously you kindly include spares of everything, even the magnets, but no spare spacer. I am flummoxed at what to do for a replacement….

    Marc LaPlante - Reply

    Hello Marc,

    Please check all the bags and boxes and your work space to see if it just didn’t roll under something. If not, contact us on email and mention your order number, we’ll help you!

    Martin L. - Official Prusa CS -

    One of my screws was not sitting below the surface of the bed. I swapped it out with one from the spare bag and that screw sits perfectly under the surface like the others.

    Spenser Holen - Reply

    Tip to other users - the magnetic underside of the bed likes stealing your hex keys (and other metal bits), make sure to check your hex key inventory and the underside of the bed for hangers-on at the end of this assembly step!

    Planar_Dragon999 - Reply

    Of the 13 M3x12b screws I received (9 in the ‘PSU & HB - MK3S v2’ bag and 4 in the spare bag), 7 have a head diameter of 5.8 mm and fit nicely into the bed with the screw head slightly recessed. The other 6 screws have a head diameter of 6.0-6.1 mm and do not sit flush even when tightened. I was able to file down the heads of the oversized screws, but other people might have issues here.

    Ben Davidson - Reply

    Hello Ben, even if so, the automatic calibration should be able to compensate for this.

    Martin L. - Official Prusa CS -

  26. This check is valid only for the old design (screw oriented upwards).
    • This check is valid only for the old design (screw oriented upwards).

    • Let's make sure the cables from the hotend aren't in contact with the heatbed.

    • By rotating the threaded rods (anticlockwise) at the same time, lower manually the X-axis down until the nozzle is almost touching the heatbed.

    • In case the P.I.N.D.A. sensor touches the bed before the nozzle, move it up slightly.

    • Ensure there is a gap between the screw in the heatbed and the surface of the hotend cables. The gap should be 2-3 millimetres, the steel sheet will add another 1 mm.

    • In case the cables are rubbing against the screw, adjust them (push them up in the extruder)

    • In case you are unable to adjust the cables, unscrew the M3x10 screw and use a spare M3n nut to shorten the length of the thread. Then place the screw back.

    on my printer, it rubs pretty bad. I'm not too sure how to fix this, even a zip-tie won't solve it. I believe if the heater cartridge would come from the other side it would not interfere with the block. I will try to see if I can just flip the plastic part around to clear some space

    Pascal Robert - Reply

    Update, turns out my wire was not properly routed, but I still find that the screw that protrudes off the plastic is too long, it should be a M2x8 instead of a M2x10

    Pascal Robert - Reply

    Hey Robert, we are looking into this. Thank you for the feedback.

    Filip M - Official Prusa CS -

    If you can, I suggest to cut the M3 x 20 bolt down to 14-15 mm. I used a dremel and a part off wheel. this will eliminate the possibility of a snag.

    Matthew Hall - Reply

    Definitely too long on my printer. Looks like an M3x8 bolt would be perfect instead of the M3x10. Thought about a Dremel solution, but ultimately removed the M3x10 bolt, just threaded a spare M3n nut up to the head, then re-inserted through heatbed and into cable-cover. Perfect fit and no need to modify a bolt and no need for Prusa to provide a single M3x8 bolt in the kit.

    Maybe just modify Step 7 instructions?

    Todd Kanning - Reply

    Excellent Tip Todd. The spare M3n nut worked perfectly for me

    Sam -

    Great call, Todd! I did the same on mine.

    Keith Illg -

    Great idea! Thank you.

    Bryan Bostrom -

    Todd is Godd <3

    Wesley Boynton -

    Great solution!

    John Dupras -

    It was at this point I realised I had mounted the entire extruder assembly on the -axis backwards….

    Jonathan Tall - Reply

    Strange that this was not mentioned during the cable management steps for the extruder. Could you please add a warning for this? i had to re-organise my cabling during this step. For the rest, i am having a lot of fun ;-) , keep up the great work you guys, i love my printer already.

    Koen Verbeeck - Reply

    Hello Mr Verbeeck,

    Thank you for your kind words! We will consider your suggestion.

    Martin L. - Official Prusa CS -

    I had to add a square nut under the head of the M3 screw to prevent interference with the cable.

    Jeff Keyzer - Reply

    the nut addition worked for me also.

    george e bancroft jr - Reply

    Nut worked for me too. Thanks

    Grace - Reply

    Be nice if this had been mentioned BEFORE we carefully screwed the hotbed down….

    Lessian - Reply

    Hi Lessian, what did you screw on the hotend? You’re just supposed to insert it. Also this is more to check the cables position.

    Martin L. - Official Prusa CS -

    I think Lessian , is talking about the tightening sequence of the bed screws

    Alex - Reply

    Please someone help me , I try to calibration on first layer cal but always machine restart or sometimes the filament out a little bit and stop .

    Takahashi - Reply

    Hi Takahashi, please contact our tech support via LiveChat here: https://shop.prusa3d.com/

    Filip M - Official Prusa CS -

    What checking are the yellow arrows trying to convey? Also, why an end of a nearby screw comes out a log? Mine is like the one shown in Step 20.

    pcprusa - Reply

    Hi,

    Yellow arrows refer to the first point in this step to be mindful of space between the screw and hotend cables. We will change the black dot to yellow to reflect this, thanks for pointing this out. As for the screw being too long, you can screw an M3n nut on the bottom of the screw before screwing it into the heatbed clip, as suggested in the last point in this step.

    Marcin M. - Official Prusa CS -

    Will be helpful if you put in the assembly kit a plastic washer to rezolve te screw being to long, also to prevent the damaging of the heat Bed between + and - connections. Also I suggest the same hard plastic washers betwen the heat bed and the end screws on the same connectors for the same reason.

    IonutMunteanu - Reply

    Your writer is not seeing this from the customer’s perspective. “This check is valid only for the old design (screw oriented upwards). “ Which screw? How could the customer possibly know if they have old or new? What do the yellow arrows mean? Why not show a photo of old and new so I can determine for myself?

    thomas king - Reply

    Agree with Thomas. I had no idea whether this applied to me. Now I see what it means, it’s obvious - but I did have to play “spot the difference” between my unit and the picture, to even understand what was being said here.

    Mat Smith - Reply

    IMPORTANT: all users should check this, not just those with the old design. Although I don’t have the old design (protruding screw), I followed these instructions from curiosity and discovered that the tiny thermistor cables were rubbing against the heatbed plastic cable cover. As these cables are delicate, this could cause problems. The reason: although the tiny thermistor wires from the hotend and the thicker power cables had been placed into the designated groove correctly, I had put the thicker cables nearer the top (into the groove) and the thermistor wires went underneath. They were both tied up properly, however the smaller cables were able to come a bit loose around the side of the thicker ones (where they actually exit the hotend) and cause this problem.

    I recommend (a) updating this section to apply to ALL users to do a clearance check (especially users with the old design with protruding screw), and (b) updating the section in the Y axis assembly where the cables are cable tied into that groove.

    Mat Smith - Reply

    Hey Mat,

    So you think it’s not clear enough until here that the cables need to be tightened firmly around the cable holder part?

    Martin L. - Official Prusa CS -

    Agree with Mat here. Disappointed to get this far and now have to deal with this.

    Ray Kuyvenhoven -

    Hello @rjkuyvenhoven

    Again, you are not supposed to be dealing with this only just now, the hotend cables should be already well arranged at this point, this step is just a reminder and double-check.

    Martin L. - Official Prusa CS -

    Hi Martin,

    “Should” is the operative word. I’ve reviewed the documentation several times and I don’t see any prior indication or warning that clearance could be an issue and be sure everything is neatly tucked away appropriately. I had the wires a bit loose to ensure there wasn’t too much strain on the connections to the hot end. Fortunately, there wasn’t too much slack and I was able to tuck the thinner wires under the thicker wires and added an addition zip tie to keep things in place. But it would have been nice to have a warning in the appropriate E-axis assembly section.

    Ray Kuyvenhoven -

    Hello @rjkuyvenhoven,

    OK then, I will report it upstream.

    Martin L. - Official Prusa CS -

  27. For the following steps, please prepare: 24V power supply (1x)
    • For the following steps, please prepare:

    • 24V power supply (1x)

    • Power panic cable (1x)

    • power cable (2x)

    • M4x10r screw with dome head (2x)

    • M3x10 screw (2x)

    • The PSU is designed to work worldwide and automatically switch to the local voltage.

    • The cable terminals (connectors) have a different width, make sure you follow the instructions. The blue terminals won't fit the Einsy board.

  28. Turn the back of the printer towards you and locate the PSU holders. Insert M3x10 screws into them. Make only 3-4 turns, it should be enough to hold the PSU for now. Take the PSU and place it above the screws. Adjust the span of the PSU holders. Slide the PSU on the screws and tighten them, but not too firmly. We need to adjust the position in the next steps.
    • Turn the back of the printer towards you and locate the PSU holders. Insert M3x10 screws into them. Make only 3-4 turns, it should be enough to hold the PSU for now.

    • Take the PSU and place it above the screws. Adjust the span of the PSU holders.

    • Slide the PSU on the screws and tighten them, but not too firmly. We need to adjust the position in the next steps.

    • Make sure you can slide with the PSU up and down.

    • The screws should be able to hold the PSU in a "vertical" position for now.

    The slot for the screws on my PSU (newer black one) were slightly tapered, so the M3x10 screws would not easily go on. I had to gently tap the top of the PSU to get the screws past the first part of the taper (once it was past that part, it moved freely like the instructions state).

    Joshua Brannon - Reply

    slots can not slide. recommend change design. washers.

    Nahuel Carou - Reply

    Seems I placed my PSU holders in the upward slot rather than the outward slot of the rear leg. Wondering if there is an elegant fix for this. Seems I have to undo a lot of things that can only be redone in the original order, i.e. start over, and face the risk of additional mistakes…

    HappyHermit3D - Reply

    Hello Happy,

    I confirm, that that’s exactly what you need to do. You always have to read the instructions carefully and observe the photos.

    Martin L. - Official Prusa CS -

    Thanks for the quick reply. Too faint of heart to start over from the beginning- my mistakes will multiply.

    So, I placed a shim under the Y-axis smooth rods (on top of the inner edge of the vertical frame) made out of a length of coat hangar wire and some duct tape so they won’t move when I remove the back plate. I think I can re-align the Y=-axis belt as necessary. I’ll try removing the back plate now.

    “Fools jump in where angels fear to tread.” Here goes.

    HappyHermit3D - Reply

    The screws holding the back plate will not be moved. WD-40 doesn’t help.

    So even starting over is not an option.

    Failure is not an option.

    Seems I will have to affix the power supply in position some other way.

    I welcome suggestions.

    HappyHermit3D - Reply

    Concerned that the next step warns “there is a risk of deforming the frame”.

    If the PS is mounted using only the two M4 screws in the vertical frame, without the PS holders affixed underneath, this would deform the frame, I think. Comments?

    I’m thinking of 3d-printing plastic “hooks” that could fill in for the PS holders, but is plastic strong enough?

    HappyHermit3D -

    Seems there is an elegant solution.

    There are two screw holes to either side of the slots for mounting the PSU.

    I placed two M3 screws in those screw holes, with the heads placed towards the center of the printer. Those heads seem just the right size to fit onto the top of the slot in the aluminum extrusion to support the PSU vertically in just the position to match the screw holes on the vertical side of the PSU to the corresponding holes in the vertical frame.

    I didn’t see any other place in the instructions where those PSU screw holes are used.

    This seems a bit too good to be true. Please advise.

    HappyHermit3D -

    Hello Happy.

    We cannot recommend anything else than to follow these instructions, even if you are faint of heart. No bypassing. But yes, the PSU is attached also by 2 dome-head screws that go through the vertical frame. These could be able to hold the PSU on their own.

    Martin L. - Official Prusa CS -

    I did the same as HappyHermit3D. And I know why, and I had followed the instructions exactly correctly. Here’s what happened.

    After opening the printed manual, which advises to follow online instructions, I Googled for the instructions and landed on the page for “Original Prusa i3 MK3 kit assembly v3.06 “. Everything looked exactly right and I only realised I was looking at obsolete instructions when I hit a point where a printed part was the wrong colour, and some other anomaly. One other person commented on this, and was helpfully advised in the comments section that he was using the wrong manual. I realised I was doing so as well. Luckily the instructions were exactly the same to that point, so I moved on and didn’t worry.

    However, it turns out, the instructions were NOT the same. Those instructions do call for mounting the PSU holders in the top section.

    After having spent 9 grueling hours putting my printer together, and getting everything absolutely perfect, I was extremely depressed to discover this!

    Mat Smith - Reply

    … continued: However, right now, I can’t see any good reason why I would have to start from scratch, surely I could just remove the back plate, which would necessitate only removing two rods and the motor pulley, and re-aligning these parts as well as re-levelling. This would allow me to change the location of those nuts to the correct part of the aluminium extrusion, on the side.

    Mat Smith - Reply

    Hello Mat,

    Yes, you don’t have to start over from scratch. Just make sure everything is tight and aligned at the end.

    Martin L. - Official Prusa CS -

  29. FOLLOW THE INSTRUCTIONS, there is a risk of DEFORMING THE FRAME! Insert M4 screws in both holes in the frame. Adjust the position of the PSU, there are holes in the casing, which must align with the holes in the frame. By default the PSU is lower than needed, pull it slightly up.
    • FOLLOW THE INSTRUCTIONS, there is a risk of DEFORMING THE FRAME!

    • Insert M4 screws in both holes in the frame.

    • Adjust the position of the PSU, there are holes in the casing, which must align with the holes in the frame. By default the PSU is lower than needed, pull it slightly up.

    • Tighten the M4 screws but not too firmly, wait for the next instruction.

    • Before tightening the M4 screws, make sure the PSU is pressed against the printer (aluminium extrusion) and also in direct contact with the vertical frame.

    • Everything aligned? Tighten the M4 screws.

    • Now, tighten the M3 screws connecting the PSU with the extrusion.

    threads female with awfull quality. too tight.

    Nahuel Carou - Reply

    I don’t know if this is a quality issue or a documentation issue but until I read Nahuel’s comment I thought that Prusa had sent me the wrong screws for the PSU.

    Jonathan Taylor -

  30. WARNING: Triple-check you have connected the cables correctly!!! There is a risk of damaging the PSU or the printer itself, if the cables are connected incorrectly or not tightened properly!!!
    • WARNING: Triple-check you have connected the cables correctly!!! There is a risk of damaging the PSU or the printer itself, if the cables are connected incorrectly or not tightened properly!!!

    • Make sure the bent part of the cable connector is always facing up!!! Use the side with the blue cover. These connectors are slightly wider and won't fit in the Einsy board.

    • Note that the polarity on the PSU is:

    • Positive

    • Positive

    • Negative

    • Negative

    • Keep this in mind while connecting the cables! The next step shows the correct wiring of the cables.

    You confuse things by having different colour connectors in the instructions to how the cables are made up. Also I have a red connector on a black cable and blue on the black cable, second cable is the other way round! I have all was being told red for positive!

    Michael Bond - Reply

    Hi Michael, you should be using the wire itself for positive/negative identification, not the crimp. See next steps for clarification if needed.

    Filip M - Official Prusa CS -

    Is there a reason we couldnt do this bit while that part of the power supply was still easily accessible?

    Lessian - Reply

    Hello Lessian,

    We are always trying to decrease the chance o customers touching anything electronic as eclectronics might get damaged by static electricity. So safety is the main reason we always instruct you to mount the electronics and only then conect the cables.

    Martin L. - Official Prusa CS -

    Please mention in the instructions that there is further clarification of cable connection order in the next step.

    Lessian - Reply

    Hi Lessian.

    Thank you for your feedback. Good point. We’ll add this notice to the text.

    Vojta Z. -

    You might want to mention you have two different terminal sizes on those cables…install it backwards and it won’t fit the enisy board terminals…

    Mel Patrick - Reply

    Hi,

    good point regarding the difference in size, note added. Thanks for the suggestion ;)

    Jakub Dolezal -

    Once step 29 was done and the PSU was in position, I just took the PSU right off and did all the power cable connections with it resting down and accessible. The connections are simply clearer !

    Re-aligning it and repeating step 29 is a lot easier than fiddling all those critical connections while tipping the entire frame, and you can’t even rest the frame on a different side, there’s stuff in every direction now. One of the bottom screws is less accessible, but the ball-end hex key takes care of that.

    I understand the concern for static but it is easier to deal with than to do these connections upside down. If this makes sense, please swap step 29 to the end.

    Arachnic - Reply

    Hello Arachnic,

    Thank you for your feedback! Swapping the steps was already considered, and we have decided to keep the order as it is. It is slightly less comfortable, but safe.

    Martin L. - Official Prusa CS -

    It could be a good idea to have the blue connector on both sides of the power cable, it will make it easier to differentiate them from the heatbed later on.

    Paul - Reply

  31. Release the screw on the FIRST (positive) slot from the left. Take the first power cable and choose the RED wire, slide it all the way in. Make sure the steel washer is above the &quot;fork&quot; connector. Tighten the screw firmly, but keep in mind some parts are made from plastic.
    • Release the screw on the FIRST (positive) slot from the left.

    • Take the first power cable and choose the RED wire, slide it all the way in. Make sure the steel washer is above the "fork" connector.

    • Tighten the screw firmly, but keep in mind some parts are made from plastic.

    • Release the screw on the THIRD (negative) slot from the left.

    • Take the same cable and choose the BLACK wire, slide it all the way in. Make sure the steel washer is above the "fork" connector.

    • Tighten the screw firmly, but keep in mind some parts are made from plastic.

    • Check the connection again! Red wire is in the first slot and black in the third.

    SUGGESTION

    There are two power cables.

    It’s a good idea to mark the cables to identify cable 1 and cable 2.

    WHY

    Many steps later (ELECTRONICS ASSEMBLY / STEP 24), you will be attaching the other end to the EINSY-base (the think in the static bag) and it’s a good idea to attach using the same configuration to the power supply.

    NOTE - chat said it doesn’t matter. Here’s a copy/paste of their response

    It's not REQUIRED but it would be ideal if you could do so as this could cause troubleshooting future problems much easier and less confusing

    HOW

    1. I used a white sharpie and placed a single dot on both ends of one of the power cable.

    2. Alternatively, you could put a small piece of masking tape on both ends. After you connect to the EINSY-base in later steps, just remove the tape.

    Ron - Reply

    The Philip's screwdriver in the kit is size P1, however the screws on the PSU are size P2 or slot screwdriver. This makes loosening or tightening the screws difficult. I suggest using the correct size screwdriver. It will save the screws and screwdriver from being damaged.

    wolfgang613@yahoo.com - Reply

    It was the same on mine. If you use an incorrect screwdriver, you risk wallowing out the grooves of the screws in the PSU. This would render the leads inaccessible and prevent one from being able to properly finish power cable connections.

    Jacob Lamberson -

    Same here, the red Phillips screwdriver that’s included is useless for this.

    Geoff -

  32. Release the screw on the SECOND (positive) slot from the left. Take the second cable and choose the RED wire, slide it all the way in. Make sure the steel washer is above the &quot;fork&quot; connector. Tighten the screw firmly, but keep in mind some parts are made from plastic.
    • Release the screw on the SECOND (positive) slot from the left.

    • Take the second cable and choose the RED wire, slide it all the way in. Make sure the steel washer is above the "fork" connector.

    • Tighten the screw firmly, but keep in mind some parts are made from plastic.

    • Release the screw on the FOURTH (negative) slot from the left.

    • Take the same cable and choose the BLACK wire, slide it all the way in. Make sure the steel washer is above the "fork" connector.

    • Tighten the screw firmly, but keep in mind some parts are made from plastic.

    • Check the connection again! Red wire is in the second slot and black in the fourth.

  33. Take the Power panic cable and connect it to the PSU. Both ends of the cable are the same, use any. Gently bend the Power panic cable and place it close to the power cables. Be careful as you might snap the entire connector from the board, keep that in mind until the printer is fully assembled, don't pull the cable.
    • Take the Power panic cable and connect it to the PSU. Both ends of the cable are the same, use any.

    • Gently bend the Power panic cable and place it close to the power cables. Be careful as you might snap the entire connector from the board, keep that in mind until the printer is fully assembled, don't pull the cable.

    • Guide the cables to the other side of the printer. We will fix them to the frame later on.

    • Don't place the cover on the PSU, wait for the next chapter.

    On this step, it appears that the black wire is on the right, and the white on the left. The connector will only sit one direction, but in this orientation, the black wire is connected to the prong marked “V+” and the white wire is connected to the prong marked “V-”.

    Is this correct?

    Joshua Brannon - Reply

    Hi Joshua, the white wire should end up on the left side.

    If you received a connector that has a different pinout, then you can either swap them or contact us for replacement.

    Filip M - Official Prusa CS -

  34. Slightly harder chapter, but have 10 %. We need to keep more for the next.
    • Slightly harder chapter, but have 10 %. We need to keep more for the next.

  35. You're getting closer! Just one more chapter and the assembly is done!
    • You're getting closer! Just one more chapter and the assembly is done!

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

    • Don't place the steel sheet on the heatbed yet. Wait for the instructions in the Wizard during the calibration process.

    • Ready for the last assembly part? 8. Electronics assembly

    Great instructions, good reminders for positioning and sequencing.

    jim Jacobson - Reply

    Thank you very much, Jim! :)

    Martin L. - Official Prusa CS -

Finish Line

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Jakub Dolezal

Member since: 02/20/2017

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3 Comments

Might want to start checking the PSU mounting gaps for the 3x10 screws before they ship. Mine were too narrow and would not slide onto the screws.

A little filing opened it up enough, but might cause some complaints with other customers.

Mark Lamb - Reply

Hello Mark, thank you for the feedback. Perhaps the screws were tilted a bit and that prevented an easy slide.

Filip M - Official Prusa CS -

I also could not get the screws on without using an Exacto to scrape off some paint. I could not force the screw into the slots when I had the PU removed from the machine and pushed on both sides of the screw at the same time - not a tilt issue on mine.

Gerald Bracken - Reply

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