[kaliken]

Originally Posted by ShaneP

There is a 12" stroke, 3/4" bore air cylinder tucked inside the arm which extends and retracts it.

We had used PVC back in 2005 for the arm, but for rigidity and ease of mating components (square aluminum extrusion for lower portion of arm), we opted for a fiberglass tube. We are using the same fiberglass tube for 2011 as we did in 2007.

Getting the arm rigid enough to overcome a low bending mode is something I have seen many teams fail at doing successfully. You guys seem to have nailed it! I heard that Joe can nail the positioning within 1cm or so.