Testing!

I need to have some base performance metrics to base the next phase of my design with, and something to test my control algorithms on, so I built this useless looking wooden box. I also wrote some control software in Matlab to remove non-linearities in the output angle of the servo.

The device applies a constant force to the Animation Rack output via a bag full of lead shot (seen in blue). I varied the mass until the servo was no longer able to sweep past it’s point of lowest mechanical advantage. The resulting torque values recorded ARE NOT indicative of maximum torque, or stall torque. They are a function of dynamic loading and are likely influenced by friction in the Animation Rack design. So don’t say that Hitec is falsely advertising their output torque, I just measured this in a way that is useful for this project.

I think I damaged servo 4 somehow. It is hard to backdrive and it’s performance is much lower than all of the others. For that purpose, I have listed average results with and without it.

What is next? Well I take these numbers and design the actual EAR part of the Secret Ear Project (Finally). I needed to know the available torques so I could size return springs and find suitable bearings.