Ultimaker extruder gears

I recently created some gears for my Ultimaker.

These spur gears are created especially for laser cutting. Prefered material is POM (delrin). They work perfectly as seen in the video:

https://www.youtube.com/watch?v=AAAizfJgaWM

there's nearly no backlash at all. I was actually really surprised how well they worked.

The hex nut can be pushed in with some force. This little gear is made for a non-D-shaped shaft motor and should also be placed by force.

I cutted them in 3mm thick Delrin but 5mm should probably better.