Monday, 18 August 2014

Harmonic Drive Update 3

Well I found some time to work on the harmonic drive the other day. I achived
about 5.8 Nm of torque reliably during testing the drive slipped when i applied a
17Nm load. When I examined the drive i found  the wave generator was not
forming the flex spline correctly I upgraded the drive to use 2 608 bearings but still not working as good as i hoped. After a bit of research i found a better wave generator design using a elliptical plug and a thin wall bearing the challenge was to design it in CAD then print it after a few tries I had a wave generator that worked at high speed and wouldn’t slip. My test drive is not up to the task of
testing so I need to reprint the whole thing again . Instead of using a gear motor I want to use a Nema 17 stepper motor and fit the encoder in the side. Below is the steering actuator from omni_bot2

Below is my latest wave generator, the flex spline is printed in nylon and is holding up well the print quality is bad with the teeth being a bit smaller then they should be