pic: CVT drivetrain

[ahecht]

Originally Posted by jgannon

A genuine CVT on a FIRST robot would be an innovation. Maybe it will turn out that the team who does it (next year, maybe?) would have been better off with an Andymark shifter. Obviously, then, the team shouldn't get an award. What a total waste of time.

Keep this in mind:How inefficient will the first FIRST CVT be? We don't know. In response to your question, inefficiency neither pushes the envelope, nor deserves to be rewarded. New approaches and inspiration do both. That's why I'm confident that whoever gets the first CVT on the playing field will gain acclaim here and with the judges, regardless of its efficiency.

I will point out again here that 190 did use a true CVT (of the torroidal design shown here) on their 2002 robot. While I don't know the efficiency of the system, I can say that we never experienced any slippage (and all the rubbing parts were smooth cast iron, not rubber or wierd hybrid gear thingies). The rotation of the two idlers was controlled by a single motor, since they do not need to move independantly of each other.

Yes, the system was very noisy, and we didn't get the programming figured out until well into the 2003 season (you try programming a reliable PID controller in pBasic), but it did show promise, and I would hope that more teams would try ambitious projects such as this. It may take several generations before a radical design such as a CVT can show a clear competative advantage, but we will never find out if teams aren't willing to try.