This arm represents our best effort to make something that is reliable, yet simple to operate and control. It pivots 60* – from horizontal to scoring position – via a pneumatic piston and extends to nearly twice its original length through a window motor driven telescoping mechanism. A third segment adds additional length so that we may, if it's useful, score tetras onto the center goal. We can vary the length of that segment in the pits so as to best minimize any chance of tipping the robot has – though the chance is quite small in any case as it counterbalances itself quite well.
Also, in case you're wondering, we are not building a practice robot. 