The original set-up for our arm was created for a device designed to aim satellite discs. As you can see in the video, it was very slow (but accurate), but after some major adjustments, it is considerably faster:
http://www.teampyrotech.org/?p=787
http://www.youtube.com/watch?v=2vu3-q3rmcY
(Look at the clock at the corner to see the length)
Any support/comments would be greatly appreciated. 