Compact Extruder for Cyclops/Chimera

thingiverse

I finally uploaded a change to the design that I've been tinkering with for a while now. It moves the BLTouch mount so that it sits in a recess carved out of the Rail Spacer object, which reduces the amount of filament required and makes setting up fans easier. This also expanded my functional build volume. The old files are still available in case anybody prefers them - they're identical to this new design. This is a compact dual direct-drive extruder I designed specifically for the E3D Cyclops/Chimera on my RepRap Folger Tech 2020 Prusa i3 printer. Since most other designs would have taken up too much space on the X-Axis, I decided to create my own. By rotating the motors, I could make the design narrower and get back that lost print space along the X-Axis. My design faces the two motors towards each other straddling the chrome rods on the X-Axis & offsetting them so they can be attached using standard M3 screws. Additionally, I don't use any bearings on the idlers because cutting the PTFE tubing in a semicircle around the drive gear works just as well and prevents flexible filament from escaping. All you need to assemble this (minus the Cyclops/Chimera) is a large supply of M3 nuts and bolts. The ones I used are from Hilitchi and are pretty cheap on Amazon if you live in the US. The RailSpacer model keeps me from losing ~12mm of print space due to how my endstops are set up. If your Prusa can reach the full print area without this extra boost, go ahead and skip that piece. Fan mounting points are located at the front, although I'm still working on a better solution for active layer cooling. There are also two cable tie brackets on the upper right to immobilize any delicate wires and keep them in position. The design was created in Fusion 360, so I've uploaded a STEP file if anyone wants to remix it. Printer Settings: * Printer Brand: RepRap * Printer: Modified Folger Tech 2020 Prusa i3 * Rafts: No * Supports: No * Resolution: 0.2 * Infill: 40% Notes: Designed to print without supports, active cooling fans will help a lot. There are lots of holes on the underside of the main extruder body so running the first layer very slow will save you some headaches. Bill of Materials: * 2x Small Cable Ties * 2x PTFE Tubing - ~130mm * 20x M3 Nut * 2x M3 Bolt - 6mm * 4x M3 Bolt - 12mm * 12x M3 Bolt - 16mm * 2x M3 Bolt - 20mm * 2x M3 Bolt - 35mm You could probably get away with using a shorter bolt for the right tensioner, and possibly swap the 4x 16mm bolts on the rail spacer for something longer. Offset Notes: On the old design, the BLTouch mount location puts the probe in line with the Cyclops nozzle on the Y-Axis (Y offset 0) and exactly 33mm right (X offset +33) of the nozzle to make bed leveling setup easier. On the new design, where the BLTouch is tucked into the rail spacer, the offsets are as follows: * Z Offset = 2mm * Y Offset = 25mm * Cyclops X Offset = 0mm * Chimera X Offset = 9mm from the left nozzle, usually E0 Other Notes: I designed the bolt sinks based on the bolts I had available, which had somewhat tall caps (~3mm). They should work for other types easily as well, since shorter bolts will just sink in further and it won't have an effect. Take care to cut your PTFE tubing in the right spot! I recommend inserting it into the heat break and marking it with something. Once it's been cut you can immobilize it by putting an M3 screw. How I Designed This: Credit where due: this is my original design, but I have to give credit to Amadon for his great work. I designed it with help from some STEP files I inserted into F360 to help me model. Special thanks go to: * MKelly for the Cyclops mockup * MrProto for the extremely detailed NEMA 17 mockup * Inornate for the BLTouch mockups * Folger Tech for the 4-bearing X-Carriage I used (If this is someone's specific design, can you let me know? I'd love to credit them)