Update 2: first load tests in printer

A project log for Low cost worm gear drive for 3D printer Z axis

A low cost worm gear drive that prevents a belt-lifted bed from dropping when motor power is cut.

Mark RehorstMark Rehorst 04/06/2018 at 23:070 Comments

I installed the printed gearbox in UMMD last night and ran the first test:  lifting 4 kg at 10 mm/sec (the bed and support assembly weigh 3.5 kg):

First test of printed worm gear box in UMMD from Mark Rehorst on Vimeo.


1600 usteps/mm

100 full steps/mm

40:1 gear reduction

3 kg cm NEMA-17 stepper

40 tooth drive pulleys

2 mm pitch GT2 belt

Gearbox printed in two pieces.
This is one generation earlier than the one in the video, but it was printed the same way.
Gearbox installed in UMMD
This the gearbox installed in UMMD's Z axis. The motor is a 3 kg cm holding torque, 40 mm long NEMA-17 unit running at 1A. At 10 mm/sec the motor is spinning at 300 RPM. A lower inductance motor might be able to spin a bit faster.

More tests to come...