Want to upgrade your print-speed?
This is an extruder that allows you to mount a beefy, high-torque, NEMA23 stepper motor. You can directly attach it to the Bowden cable. With the Bowden extruder (see my other designs under the Thingiverse tag: bowden), the plastic throughput is your print speed bottleneck. Or should I say, was your bottleneck: With a NEMA23 motor I've been able to extrude more than 15 mm^3 of molten ABS per second. That's about a (fully solid) mendel in 22 hours! So now XY-movements are the bottleneck again. For this, I think I need to further reduce the weight of the carriage (lighter rods, etc.).
You can simply press the Bowden cable with an M6 nut into the T-slot (to attach the extruder drive mechanism to the extruder head via a Bowden cable).
Note: An M5 nut will also work (for smaller PTFE bowden cables), it will be able to slide slightly, but its movement is constrained by the filament.
- Make your stepper motor shaft rough (e.g. with a dremel cutting disk).
- Put an M4x16 bolt into the 624 bearing. Put a washer between it and insert it into the printed part as seen in the picture. Put another washer on the other side and fasten it with an M4 nut.
- Bolt the extruder onto the printed part, with four M5 cap screws, use washers.
- When using ABS you can tighten it so that the washers will sink into the plastic creating a very tight friction fit. It is soft enough that it won\'t crack. With PLA you should be more careful.
You can stack several of them with the mounting slots on the sides. This is useful for multi-material RepRaps. The design is future proof :)