think&have torque extruder

thingiverse

This is an incredibly powerful Bowden extruder with a 2:1 reduction ratio, boasting a unique drivegear that runs on a ball bearing. The filament is guided through a PTFE tubule, providing exceptional smoothness and control. With a 2A NEMA17 steppermotor, we measure a pulling force of above 7000 pounds (ca. 69 Newton), demonstrating its incredible strength. The Driver.stl file should not be printed; instead, it needs to be made from brass or steel for optimal performance. The printed parts include all STL files except the driver. Other required materials are: 1 Special drivegear made from a 10mm diameter brass rod, 30mm in length 1 Ball bearing 683 1 Ball bearing 608 1 Ball bearing 625 2 M3 x 50mm screws 4 M3 x 45mm screws (shorten the 50mm ones if necessary) 1 Setscrew M8x16 1 Setscrew M3x6 6 Plain steel washers M3 1 Rivet nut 5mm, M3 1 Countersunk screw M3x12 2 Short extruder springs (ID > 3mm, length can be up to 10mm, wire about 0.5mm) 1 Push in fitting 4mm/M5 1 RAMPA insert 8x8xM5 1 Piece of PTFE tubing, OD = 3mm, ID = 2mm, length approximately 30mm 1 Stepper motor NEMA17 (the stronger the better) For added strength and a nicer finish, parts (except the gear set due to precision loss) can be finished with acetone. However, this is not strictly necessary. The big gear is pressed onto the filament driver and secured with an M3 setscrew, while the small gear is only pressed onto the 5mm motor shaft. This extruder is designed for use on a flat shaft. If your motor shaft is not flat, you can ream the gear to 5mm and insert an M3 nut. To machine the filament driver: Cut a 30mm piece of a 10mm brass rod. Drill a centered 3mm hole through the entire length. Drill a centered 7mm hole, 4mm deep on one end. Insert the 683 bearing. Mount the part on your mill or lathe and machine the hobbing at a distance (center of hobbing) of 6mm from the 'bearing end' of the part. Use an M6 tap for this step. Drill the 2.5mm fixation for the big gear at a distance of 5mm from the opposite end of the part (non-bearing end) and tap it to M3. Press the big gear onto the non-bearing end of the part, and your filament driver is ready to use. To prepare the idler: Ream the filament channel to 3mm. Drill the axis mount to 3mm. Insert the PTFE tubing into the filament channel. Screw the RAMPA insert in place. Insert the push-in fitting into the RAMPA insert, pushing the PTFE tubing forward as you do so. Do not cut it off yet. Insert the 608 bearing and secure it with an M8 setscrew. To mount the extruder: Put three M3x45 bolts through the "deckel" part (leave the lower mount free). Put the tighter2 part onto the two bolts in the connected deep mounts of the 'deckel' part. Put the idler part onto the third bolt. Secure this assembly to the NEMA17 motor. Put the prepared filament driver in its place (do not forget the bearing) and insert the fourth M3x45 bolt. Review the PTFE insert. Shorten it if necessary, but leave it as long as possible, especially for printing elastic filaments like TPU. Finally, fine-tune the pressing depth of the small gear to ensure smooth operation and proper alignment with the filament channel. If necessary, use a flat screwdriver and a quick clamp to achieve this.