The ArmDrive is a 1.75mm filament bowden extruder, designed to work with the NEMA 17 stepper motor. It mounts directly to any OpenBeam or equivalent sized (15mm) extrusion. With the complimentary mounting bracket, it can also be attached at a 90° angle. The optional bracket is located here: https://www.thingiverse.com/thing:2353189

The MK7 and MK8 versions are each designed to work best for those particular drive gears, or gears with similar dimensions.

The extruder is designed to be robust and reliable, while using as much easy to find hardware as possible.

These files are the result of a surprisingly large amount of work, I hope you find they work as well for you as they do for me.

Enjoy!

Update - January 6th 2015

Revision 2

• Slightly increased the diameter of the post holding the 608ZZ bearing to reduce play and allow more clearance around the outside of the bearing near the swivel shaft area.

• Increased the radius of the bearing cutout near the swivel shaft area by an additional .2mm to allow for more clearance for problem described above.

• Significantly strengthened the input filament alignment post.

• Added more support behind the spring retainer arm on the base-plate to reduce warping over time when under high spring tension.

• Increased height of the three standalone posts on the base-plate by .2mm to allow for more torque when installing the screws without causing the binder arm to jam.

Update - October 24th 2015

Revision 3 is now available!

• Increased the rigidity of the upper and lower arm segments in response to feedback about occasional cracked and broken arms.

Update - May 29th 2017

• I have designed a 90° mounting bracket to make alternate angle installations a breeze.

https://www.thingiverse.com/thing:2353189