Gerbs Dual Motor Bowden Extruder

The purpose of this extruder motor(s) is to provide much more power than a single motor design. Prevent stalling due to ground down filament, Provide full speed of the extruder motors with no gear reduction.

This uses a Nema 23 and a Nema 17. This design allows for 2 drive motors spinning in opposite directions. One gear on either side of the filament. It's also designed to use constant tension with a single bolt and spring. The bowden tube is designed to run alway up to the gears to provie a smooth surface from just mm away from the gears all the way to the hot end.

Cheap filament with uneven tolerances will happily be pushed out with this set up!

The only thing that i did not set adjustments for is the drive gear center. This is designed to be used with a couple of gears that have an 8mm OD. Realistically, this should work with a large range of drive gears. I can make adjustments to compensate for other sized drive gears if need be.

You made need a spacer for the motors depending on the shaft length.

Parts required for this:

1 screw (4-5mm in diameter, 25-52mm long)
1 Nut for screw that is no more than 8.75mm wide. A diy printed nut would work just fine .
1 spring, 10 mm max diameter, ~ inch long. (will accept longer and shorter springs)
Bolts/nuts to bolt to Nema 23 and Nema 17.
2 drive gears that are identical
1 Nema 17
1 Nema 23 - must be the same steps per rev as the nema 17.
1 6mm Pneumatic Air Straight Fitting -can be redesigned for other fitting sizes.
Some bowden tube that is 4mm OD.