An updated version that makes several improvements:
- Locking arm to prevent extruder wobble
- New and improved stronger tension arm
- New accessory mounting system which is cleaner and stronger
- Redesigned and streamlined filament guide to prevent filament accidentally escaping and allowing easier access for filament drive cleaning
- Improved built in support section for largest part for cleaner printing
- Added boss for left hand limit screw (to suit my replacement carriages)
- Revised mounting holes to allow greater compatibility with hot ends (should be compatible with E3D all metal hot end)
Update 1: End stop screws widened to ensure E3D hot end fitment. Thanks to OzAdr1an for testing.
Update 2: Bevelled edge body variant added thanks to 2n2r5. THis is to suit Printrbot hot ends or if you are having a hard time fitting your hot end.
Update 3: Filament guide replaced with pre-prepared version from foofoodog, should now slice for everyone.
Instructions correspond to pictures:
Print parts at high infill for strength. No support is necessary. Accessory parts are optional. Choose between standard and bevelled edge body variant. Dimensions are in mm.
Use a thin, sharp knife to remove the built in support from the body piece. It should come off fairly easily and leave behind a reasonably clean surface.
The locking arm should be a snug fit and is held in place by a M3 x 10mm bolt. The ease in which the locking arm rotates is dictated by the tension of the M3 bolt.
Move the bearing, washers and bolts over to the new tension arm. I prefer one washer at the front of the bearing and three at the back for better alignment. A M3 x 16mm bolt is a perfect length to secure the tension arm to the body.
Use the original M3 bolts to secure the body to the carriage. At this stage is it a good idea to insert the hot end. Mine is super snug and wobble free just by closing the locking arm.
Attach the extruder stepper motor to the assembly using more M3 bolts. The new filament guide piece (top piece) is modified to make it more compact and allow easier cleaning of the filament gear. On the left side a M3 x10mm or similar bolt is needed to secure it. At this stage it is a good idea to insert M3 bolt(s) underneath the body piece to hit the end stop(s).
- The extruder is complete at this stage but if you are paranoid about the locking arm coming loose, you may like to clip a blank accessory piece in from above to hold it closed. You may need to swing the tension arm all the way down to the right to provide temporary clearance. This blank piece is actually intended for fan shrouds and other accessories to be glued onto.