Upper Legs & Hips

This page is about building the upper legs and hips. Check out the main project index for the rest.

There is a YouTube video about this section, or scroll down for pictures and words:


I’ve designed the upper legs to be very much like the lower legs, with the addition of a vertical rotary axis to allow each leg to turn – this allows the robot to turn on the spot on walk in a curve. For now this axis is locked until later on in the project when I install an actuator.

I’ve used a piece of stainless steel tube mounted with 3D printed collars in two bearings which allow this rotational axis. I needed to remove as much flex in this axis as possible so the hips are probably overkill with cross bracing and right-angle brackets. The bearing blocks are also 3D printed and took 12 hours each in Colorfabb HT.

I still have some work to do on the actuators which will need refining as time goes on, but the structure is looking good for now. Check out the video above for more detail.