DRAFT – these instructions are not final, and are likely to change.

Drive block

You will need the following parts:

# Component Qty Type
 408 NEMA 17 stepper motor 1 Electronics
 242 M3x16mm cap head screw 2 Fastener
 1239 Drive block 1 Printed
1255 Drive block spacer 1 Lasercut


Place the motor onto the spacer. drive-spacer-placed
 Attach the drive block using the two cap head screws as shown. drive-block-assembled

Idler bearing

You will need the following parts:

# Component Qty Type
279 623 bearing 1 Hardware
 702 M3x10mm cap head screw 1 Fastener
258 M3 nut 2 Fastener
212 M3 washer 2 Fastener


Assemble the idler bearing with a nut and washer on each side of the bearing. drive-idler-assembled


You will need the following parts:

# Component Qty Type
Idler bearing 1 Assembled
 1237 Lever 1 Lasercut
 1238 Lower lever 1 Lasercut
 702 M3x10mm cap head screw 2 Fastener


Slide the lever into place, insert the idler bearing assembly, then fit the top lever. Secure at the pivot point with a cap head screw. Finally, screw the remaining cap head screw up through both levers. The hole in the top lever is smaller than in the lever, such that the screw will bite into the plastic. lever-assembled

Spring assembly

ou will need the following parts:

# Component Qty Type
650 M4x35mm button head screw 1 Fastener
1193 M4 nut 3 Fastener
1185 M4 washer 3 Fastener
1250 Idler spring 1 Hardware


Fit the washer, spring and nut (in that order) to the button head screw. drive-tensioning-screw-assembled
Slide the assembly into the drive block as shown. drive-spring-fitted


Hobbed insert

You will need the following parts:

# Component Qty Type
 1181 Hobbed insert 1 Hardware
1183 M3x3mm set screw 1 Fastener


Slide the hobbed insert onto the motor shaft, then slip some filament through the drive block, to engage with the teeth on the hobbed insert. Add a small drop of thread lock (or superglue) to the set screw, then screw it into the hobbed insert and tighten onto the flat of the motor shaft. Take care not to strip the head of the screw. drive-complete


Mounting the drive

You will need the following parts:

# Component Qty Type
Fisher 1 Part-assembled
Extruder drive 1 Assembled
1236 Drive spacer 1 Lasercut
152 Tongue 1 Printed
241 M3x20mm cap head screw 2 Fastener


Insert the drive spacer between the extruder drive assembly and side panel, then secure using the two cap head screws. extruder-drive-mounted
Push the bowden end into the drive block. This should be a snug fit. bowden-start-inserted
Ensure the bowden start is fully inserted. bowden-start-inserted-outer-view
The tongue is used to retain the bowden tube during printing. Take care to orientate the tongue as shown. tongue-approaching
Push the tongue fully into the slot. tongue-fitted
Finally, push the extruder thumbwheel onto the end of the stepper motor shaft. This allows you to move the extruder manually, which is helpful when loading filament. Picture to come