Welcome to the build guide! Before you assemble, make sure you grab everything you need– tools, printed parts and ordered parts. All hardware is M3 unless otherwise stated.

  1. Print the parts

    Check out the Printed Parts page for important information.
  2. Install the software

    Use the Software Guide to install the required software on to the Raspberry Pi and SKR Pico. The SKR Pico is hard to reach once the Lemontron is assembled!
  3. Insert the screws

    Drop two screws into the holes.
    button-head
    M3
    40mm
  4. Scrape the mating surface flat

    Using a blade, lightly scrape the surface. This will remove any gaps and make the parts fit together beautifully.
  5. Screw in the spine

    Secure it with 5 screws.
    countersunk
    M3
    14mm
  6. Install the posts

    Onto the screws, drop a 12mm washer, small bearing, another washer, a yellow spring that's been cut in half, and a nut.
    button-head
    M3
    20mm
  7. Follow the old machinists tapping tip, which is to drive the screw in, back it out, and drive it in some more, over and over. This is the best way to ensure you can reuse the plastic threads.
  8. Gather Z-Axis parts

    Gather the Z axis (printed), bracket (printed), MGW9C linear rail, 6 × 3d-printed spacers, 6 × 8mm countersunk screws, 2 × 25mm wafer head screws, M5 shims, M5 bearings, lead screw & nut, drive pulley and belt.
  9. Insert the bearings

    Insert the two bearings into the bottom seats. Optionally, insert an additional bearing in the top seat.
  10. Insert the lead screw

    Insert the lead screw through so that it just pokes through the bottom bearing.
  11. Drop in the first shim

    Drop in the first shim. This shim allows the bearing to turn while pressing against the drive pulley.
  12. Drop in the drive pulley

    Drop in the drive pulley with the belt pre-installed. Advance the lead screw flush with the top of the pulley.
  13. Fish in the second shim

    Use something thin to fish in the second shim. Push the lead screw all the way through.
  14. Glue the bracket

    Dap some supa glue on the ledge on the bracket.
  15. Press & dry the glue

    Press the top of the bracket onto a flat surface while it dries.
  16. Clip off the support

    Clip off the support from the bottom with flush cutters.
  17. Insert the lead nut

    Insert the nut that came with the lead screw to the bracket.
  18. Attach the lead nut

    Attach the lead nut to the bracket. If your nut came without countersinks, you can either countersink it yourself or use button head screws. It makes no difference.
    countersunk
    M3
    8mm
  19. Add the bracket

    Install the bracket onto the lead screw.
  20. Cut the lead screw

    Align the lead screw's top with the top of the bearing seat and CUT the bottom off.
  21. Tighten grub screws

    Tighten the grub screws using a 1.5mm allen key.
  22. Install the rail & spacers

    Lay down the rail, then starting at the top hole, add 3d printed spacers to the first 3 holes, omit the 4th if you want to use the spool holder, and then proceed to add the last 3 spacers. Leave the bottom two holes empty to use to mount the Z-axis to the chassis.
  23. Screw in the rail

    Fasten the rail with screws in the holes that you added spacers to.
    countersunk
    M3
    8mm
  24. Gather edge connector parts

    Cut approximately 50cm of silicone power wire and signal wires.
  25. Solder the power wires

    Fan out the wire strands, and use the wire to bridge the two conductors as shown. Twist the end. Solder. Trim the excess.
  26. Solder the signal wires

    Solder two thin gauge signal wires to the two middle conductors.
  27. Sleeve the wires

    Cut the wire sleeve to 32cm and finesse it onto the wires.
  28. Cut the wires

    Cut the power wire to 44cm and the signal wires to 42cm.
  29. Tin the power wires

    Strip 5mm of insulation from the power wires and tin them.
  30. Note for the armchair experts who cry about ferrules
    If I hear one more idiotic comment about your stupid ferrules, I will find a tiny ferrule for your tiny benis and clamp it so hard that you'll wish I would use the iron instead.
  31. Crimp signal wires

    Crimp the two signal wires. Learn how to crimp goooood here.
  32. Insert connector

    Insert the two crimped signal wires into the JST connector. Polarity does not matter.
  33. Slide in edge connector wire

    Slide the wires in through the slot in the bracket and press the edge connector into place.
  34. Tighten bracket

    Tighten the bracket on to the carriage with two screws.
    wafer-head
    M3
    25mm
    Picture shows button head screws.
  35. Gather Lemonstruder parts

    Top & bottom halfs (Printed), super glue, yellow spring, 8mm countersunk screw, small bearing, 2 small shims (Off frame, sorry)
  36. Glue halves together

    Dap two tiny dots of super glue as pictured.
  37. Insert the first shim

    Insert the first shim, using a small screw to help guide it in. This shim will allow the bearing to rotate against the plastic housing.
  38. Insert the bearing

    Insert the bearing on top of the shim.
  39. Insert the second shim

    Using tweezers, insert the second shim between the bearing and the plastic housing.
  40. Insert the screw

    Insert the screw, pushing out the small screw. This screw is designed to not fit completely flush.
    countersunk
    M3
    8mm
  41. Insert the spring

    Insert the unmodified yellow boinger.
  42. Insert the Lemonstruder

    Insert the Lemonstruder into the left top plate.
  43. Cut motor wires

    Cut the motor wires to the lengths 15cm, 15cm, 10cm, 23cm.
  44. Crimp motor wires

    Crimp every motor wire.
  45. Insert the crimps into the connector

    Starting from the triangle mark, go in order of black, green, blue, red.
  46. Gather parts for the tool

    Tool body (printed), hotend, small fan, big fan, probe, connectors, crimps, power wires (silicone), signal wires, M2.5 x 6mm screws, pcb.
  47. Tighten the heat break

    The heat break is loose from the factory. You need to rebuild the hotend.
  48. Modify the part cooling fan

    Completely remove the two mounting tabs and wire retaining clip.
  49. Push the wires through

    Push the part cooling fan wires through the cavity of the tool head.
  50. Drop in the hotend

    The hotend will smoosh the wires and keep them in place. Now is a good time to strip the wires.
  51. Fasten the hotend

    Fasten the hotend to the tool body.
    countersunk
    M2.5
    6mm
  52. Fasten the probe

    Fasten the probe to the tool body.
    countersunk
    M2.5
    6mm
  53. Insert small fan

    Insert the small fan and push it under the ledge so that it's touching the head sink.
  54. Drop in the part cooling fan

    Finish dropping in the cooling fan to lock everything in place.
  55. Tin the pcb

    Apple some solder to hasten the wire bonding.
  56. Fasten the pcb

    Fasten the pcb to the heat sink.
    countersunk
    M2.5
    6mm
  57. Solder the hotend fan

    Solder the hotend fan (small fan) to the pads on the pcb.
  58. Solder the part cooling fan

    Solder the part cooling fan (big fan) to the pads on the pcb.
  59. Solder the heater

    Clip and strip the wires at the end of the heat shrink tube. Solder to the pads on the pcb.
  60. Shorten the thermistor spring

    Clip the spring in half.
  61. Solder the thermistor

    Clip and strip the wires and solder them to the pads on the pcb.
  62. Plug in & solder the probe

    Plug in the probe and split off one of the grounds (black or brown) and solder it to the pad. You can reuse this wire so don't throw it away.
  63. Solder the heater wire

    Solder the heater wire. Don't solder it as pictured. The pcb is literally labelled, I don't know why I flipped it but I did. I will replace this picture later.
  64. Solder the thermistor wire

    Using the leftover wire from the probe, solder the thermistor signal wire.
  65. Solder the fan wires

    Cut two wires roughly to 50cm and solder them to the two fan pads on the pcb.
  66. Wrap the wires

    Use 47cm of wire sleeve to wrap the wires.
  67. Insert the clamp

    Clamp down the wires by pushing in the clamp and securing it with a screw.
    button-head
    M3
    12mm
  68. Clip the tool wires

    Cut the heater wire and probe wires to 53cm, the rest to 55cm.
  69. Tin the heater wires

    Trim back 5mm off the heater wires and tin the ends.
  70. Crimp the thermistor wire

    Crimp the thermistor wire and insert it into the connector side without the marking.
  71. Crimp the hotend fan wire

    Crimp the hotend fan wire and insert it into the connector side without the marking.
  72. Crimp the part cooling fan wire

    Crimp the part cooling fan wire and insert it into the connector side without the marking.
  73. Crimp the probe sensor wires

    Crimp the probe sensor wires and insert them into position 2 & 3 as shown.
  74. Crimp the probe servo wires

    Crimp the probe servo wires and insert them as shown; black on the marking, white on the other position.
  75. Gather the chassis parts

    This is the rest of the parts! Draw the rest of the horse!
  76. Insert the heat set inserts

    Press in the 4 top inserts and 2 bottom inserts. These 10mm long threaded inserts are super strong. After pushing in the inserts, press down on the surface with a flat piece of metal to cool and ensure flatness.
  77. Insert the top z-block insert

    Insert the top z-block insert from the front.
  78. Insert the bottom z-block inserts

    Insert the bottom two z-block inserts from the rear.
  79. Insert the vertical chassis stiffeners

    O P T I O N A L
    Optionally add the two M4 45mm stiffeners.
  80. Insert the horizontal chassis stiffeners

    O P T I O N A L
    Optionally add the two M5 80mm stiffeners.
  81. Insert the AC input jack

    Slide in the AC jack and fasten with two screws.
    wafer-head
    M3
    14mm
  82. Electrical Shock Warning

    If caution is not exercised, this device has the potential to cause harm through injuries, burns, and electrical shocks. Do not become complacent!
  83. Modify PSU

    Bevel the two corners of the PSU that face outwards. The cut should bisect the screw post holes.
  84. Link the fans together

    Wire two chassis fans in parallel so that the wire is long enough to reach the ports on the left of the MCU.
  85. Insert the right fan

    Insert the fan and secure the bottom two screw holes.
    wafer-head
    M3
    14mm
  86. Insert the left fan

    Insert the fan and secure the bottom two screw holes.
    wafer-head
    M3
    14mm
  87. Plug in the fans

    Plug in the chassis fans to the top port of the MCU.
  88. Plug in the power wires

    Connect the power wires to the PSU and cut to length, tin the ends, and plug in. The gauge of these wires should be 18AWG or thicker. 14AWG is the largest wire the terminal blocks can accept.
  89. Plug in the probe connectors

    Connect the two probe connectors as shown- B/W on top, Y/R on bottom.
  90. Plug in the hotend heater wires

    Insert the two heater wires into the top terminal block.
  91. Plug in the hotend thermistor connector

    Insert the thermistor wire into the bottom left port.
  92. Plug in the hotend fan connector

    Insert the hotend fan connector into the second port.
  93. Plug in the part cooling fan connector

    Insert the part cooling fan connector into the third port.
  94. Plug in the bed thermistor

    Bring over the z-axis and insert the heat bed thermistor connector next to the hotend thermistor.
  95. Plug in the bed heater

    Insert the heat bed power wires into the middle terminal block and tighten.
  96. Insert the motors

    Bottom left motor has 15cm wire, bottom right has 23cm wire, top right has 15cm wire, top left has 10cm wire.
  97. Plug in the motors

    From left to right, port 1 is the top right (extruder) motor, port 2 is the bottom left (A) motor, port 3 is the bottom right motor (B), port 4 is the top left (Z-Axis) motor.
  98. Solder the serial connector

    Solder the Raspberry Pi connector as shown. You can also try using right angle pins!
  99. Plug in the Raspberry Pi

    Connect the Raspberry Pi to the serial port.
  100. Smush the MCU

    Smoosh the wires up and press the MCU into place.
  101. Insert the risers

    Install the risers, the left one covers all the wires, and the right one covers all except the extruder motor's wires.
  102. Screw in the risers

    Flip it over and fix the riser in place with two 8mm countersinks.
    countersunk
    M3
    8mm
  103. Attach Raspberry Pi

    Use four screws to attach the Raspberry Pi.
    countersunk
    M2.5
    6mm
  104. Insert nut

    Insert a nut onto the Y-Rail (MGN12C) by pulling it in from behind with a screw.
  105. Install tensioner

    On the same rail, install the tensioner over the nut.
  106. Prepare two posts

    Onto the screw, drop a big bearing, a shim, and a washer.
    button-head
    M3
    12mm
  107. Install the posts

    Install the bearing posts into the tensioner.
  108. Install the rail

    Slide in the rail. You might want to tap it down with a mallet. Verify the wires that run under the rail are tidy.
  109. Fasten the rail

    Screw the rail to the chassis. You must go slow, alternate short rotations and don't overheat the plastic.
    countersunk
    M3
    14mm
  110. Insert the bonus screw

    From the bottom, fasten the rail tightly to the chassis.
    countersunk
    M3
    20mm
  111. Tape the motors

    Tape the motors. Without tape, the wires will fly away. You need to tape it before installing the mid plates.
  112. Install the right midplate

    Drop the right midplate on top of the motors, making sure you can press it flat. Verify from every angle that there is no gap.
  113. Secure the right motors

    Secure the motors to the right midplate, filling the four countersunk motor mount holes.
    countersunk
    M3
    8mm
  114. Install the extra screw

    Add another screw to further secure the midplate to the chassis.
    countersunk
    M3
    20mm
  115. Install the lower pulley

    Onto the screws, drop a big bearing, a medium shim, and a big washer. Screw it all the way through the chassis.
    wafer-head
    M3
    25mm
  116. Install the upper pulley

    Onto the screws, drop a small flanged bearing, a small shim, another small flanged bearing, and another small shim. This post threads into the motor. The flanges serve as guides for the belt.
    wafer-head
    M3
    14mm
  117. Install extruder gear

    On the top left motor, and using several fingers, line up the top of the extruder gear with a pulley and fasten the grub screw to the flat side of the shaft.
  118. Install left midplate

    Insert the wire harnesses into the slots in the midplate and lay the midplate into position. Verify there is no gap.
  119. Tug the cables

    Remove the slack in the cables.
  120. Insert the motor mount screws

    Secure the motors to the left midplate, filling the four countersunk motor mount holes with 8mm countersinks.
    countersunk
    M3
    8mm
  121. Insert the lower pulley

    Same as the right one.
  122. Insert the upper pulley

    Same as the right one.
  123. Install the extra screw

    Add another screw to further secure the midplate to the chassis.
    countersunk
    M3
    20mm
  124. Finish right fan

    Secure the right fan's top two screw holes.
    wafer-head
    M3
    14mm
  125. Finish left fan

    Secure the left fan's top two screw holes.
    wafer-head
    M3
    14mm
  126. Install left drive pulley

    Temporarily put two sheets of paper under the pulley before tightening the grub screw to the flat side of the shaft. If there are two grub screws, tighten them both but one should be on the flat side of the shaft.
  127. Install right drive pulley

    Repeat on the right. Verify the pulleys are friction-free by grabbing the pulley forcefully and rotating it a full circle. If it catches on something, it's going to show up in your prints.
  128. Modify X rail

    Cut one hole off the X rail (MGN9C).
  129. Install right drive pulley

    Add a nut to both sides of the rail.
  130. Create bearing posts

    On the screws, drop a big bearing and a medium shim.
    wafer-head
    M3
    14mm
  131. Install bearing posts

    On both sides of the rail tighten down both bearing posts.
  132. Drop on the spacer

    Drop the spacer (printed) onto the Y axis carriage.
  133. Attach the X rail

    Drop the X rail on top of the spacer and screw it in with two screws.
    countersunk
    M3
    20mm
  134. Create bearing towers

    On the screws, drop a big bearing, a medium shim, a large washer, a small shim, a small flanged bearing, small shim, small normal bearing, and small shim.
    button-head
    M3
    16mm
    The belt rides on the normal bearing and the flanged bearing prevents it from riding up.
  135. Install bearing towers

    Screw the two bearing towers into the top positions in the Y carriage.
  136. Cut a piece of belt

    Cut a piece of belt that precisely fits into the recess in the belt clip.
  137. Dap some super glue

    O P T I O N A L
    Dap some super glue on the belt. The glue is not required, but it really makes it easier to put the belt into the clip.
  138. Link the belts

    Hold the long piece of belt to the short one, overlapping half of it as shown.
  139. Insert one side

    Insert the belt into the clip and verify that the short belt is seated properly.
  140. Insert the other side

    Insert the other side of the belt temporarily. You can trim it later.
  141. Lubricate belts

    Lubricate the sides of the belt (not the teeth) with silicone based lube. Don't AT me for using sex lube, it's a joke.
  142. Route the belts

    Hook the belt over the towers, placing it on the lowest bearing.
  143. Around the lower bearings

    Hook the lower bearings.
  144. Around the upper bearings

    Wrapping around the drive pulleys, hook the upper bearings.
  145. Around the tensioner

    Wrap the belts around the tensioner bearings, the two strands coming down the middle.
  146. Around the tower again

    Hook the tower bearings, this time the upper ones, heading out to the X rail bearings.
  147. Around the X rail

    Route the belt around the X rail. Trim the excess and reattach the belt to the clip.
  148. Screw in the tensioner

    Push the tensioner towards the Z block, then fix the tensioner in place with a screw. This should be loose.
    wafer-head
    M3
    25mm
  149. But loose belt? Is Lemontron a moron?
    You should feel the elasticity, and you should not be able to strum the belt. Why? Because it's not CoreXY! With only one belt and the same amount of friction total.
    info
  150. Thoroughly test

    Thoroughly test and tune the belt tension. When you feel that the friction is negligible, it's ready.
  151. Install top plates

    Drop in the two top plates.
  152. Fasten the outer screws

    Fasten the top plates to the chassis on the 6 outer holes along the edges.
    countersunk
    M3
    20mm
  153. Fasten the inner screws

    Fasten the top plates to the motors on the 4 inner holes. Bonus points if you fabricate 15mm countersinks for a better fit.
    countersunk
    M3
    14mm
  154. Attach the tool head

    Drop on the tool head.
  155. Screw on the tool head

    Screw on the tool head.
    countersunk
    M3
    14mm
  156. Attach the belt clip

    Flip over the printer and attach the clip with two screws.
    countersunk
    M3
    8mm
  157. Attach the Z idler arm

    Attach the z idler arm. To make the bearing stack, on a 14mm wafer head, drop a big bearing, medium shim, big bearing, and medium shim.
    wafer-head
    M3
    14mm
  158. Attach the Z axis

    Hook the Z axis drive belt on the pulley. Drop the Z axis into place. Tighten the idler arm.
  159. Screw in Z axis

    Screw in the Z axis. Rev B uses two button heads instead of the countersinks shown in the picture.
    button-head
    M3
    16mm
  160. Rough up bowden tube

    Rough up at least 1cm of the bowden tube.
  161. Pour glue on bowden tube

    Pour a generous amount of glue on the end of the bowden tube.
  162. Insert the bowden tube

    Insert the bowden tube into the top plates. There is a lot of clearance, so the glue will go all the way down.
  163. Surely there's a better way?
    Sometimes the simple solutions are the best. With the absurd contact patch of about 2cm², the glue will hold the tube until the end of time.
    info
  164. Zip tie the bowden tube

    Zip tie the bowden tube with 2 zip ties, one at 10cm, another at 20cm.
  165. Mark the bowden tube

    Holding the tube approximately where it needs to go, mark the bowden tube as pictured.
  166. Cut the bowden tube

    SNIP, SNIP! The end needs to be as straight as possible.
  167. Insert bowden tube

    Insert the bowden tube all the way into the tool end.
  168. Insert the clip

    While still putting pressure on the bowden tube, pull out the collar and install the orange clip.
  169. Attach the bed holder

    Attach the bed holder to the Z carriage with the two captive screws.
  170. Slide in the bed

    Slide the bed into the spring-loaded posts.
  171. You've reached the end!

    You just built the whole thing. Now wash up, you're probably covered in solder fumes.
  172. Sike you've not reached the end!

    Use the handy guide to do your one-time calibration.