I use to use these all the time in my first job. It are light and rigid. in the distance there are some mounted to the frame for testing.
Bearing comes from IGUS. They were great in helping pick out a bearing that could work and one that will hold up over time.
CPU Arm Late Model:
Life Form Scanner:
Zapper (RoJ body):
After countless events and meetings with some special kids and kids at heart. R2 1.0 has been retired and pieces of him are now either being or have been scatter across the globe to hopefully bring joy to others.