VEXPro - After the season

[Tom Line]

We're happy with a number of vexpro products we're using. The only item I want to mention is the traction wheels.

We're using the 6 inch version. We've seen a single problem: we're using 3 cims per side through a 3 motor toughbox. The fasteners holding the sprockets on have the wheels have worked loose several times, and are now on our list to check after each match. Our center wheels that have sprockets on both sides have been drilled out to 1/4-20 and through bolted. We haven't had a problem with those. We've stayed away from using locktight because I know it can react with the plastic with bad results.

I'm looking forward to trying the ball shifters this off-season. We usually don't use shifting drivetrains because of weight, but that may change now. I would absolutely LOVE it if Vex can look into supplying a kit that allows fast reliable shifting without pneumatics. In fact, with a little innovation, it's not impossible for the same kit to work on the supershifters as well. I've seen a number of solutions. The most elegant I saw was a single window motor with spring loaded arms (Hot in 2012). The servos are simply not powerful enough to shift under load. I've seen very few teams use them for exactly that reason. We plan on putting the ball shifters on our robot for the off-season to test them out, and will probably look at a solution at that time (we don't have pneumatics on this year's bot). There was a fellow at MARC last year with a really nice sliding arm linkage made out of lexan that was along the same lines - just bolt on a window motor and go.