Sunday, 24 February 2013

Harmonic Drive 2

After Robbies shoulder gear failed with a broken tooth I stepped up work on the harmonic drive I have a first draft model for engineering fits and clearance. The flex
spline proved the hardest part to print I had to change the print setting until i got a good print I'm still waiting for the bearings for the wave generator so i can start testing

 A mixture of files some mine and most from

 Slowly starting to get the hang of CAD

A broken tooth this part in the shoulder lift joint has the most force applied


  1. Hi Peter, very sorry to see this. I think PLA is maybe too brittle for the gears, and I think it might be even worse with the soft spline of the harmonic drive.
    I will definitly follow your new harmonic drive concept.

  2. The spline is made out of ABS. The way the drive gear is printed can be improved
    the teeth have voids in them if i use a smaller extrusion width it will make the gear stronger( learnt from printing the spline)

  3. hello peter
    i find your projet very nice so me to i would like tu use a drill motor and i buy 6 drill motor lol but i dont know how i can control it?
    have you one idea?
    excuse me for my bad english i am french

  4. the easiest way is a arduino and motor shield but that can get expensive.
    What i use is a l298n motor drive (both out puts connected together) with a atmega 383 ic and a home made PCB (at the monent is 2 PCB and lots of wire)
    then i have a PID controller software and a python node to control it through ROS if you want the code let me know