[JAlpert]

Team 469 shifted the drills with the servo in 2001. The problem is that when you first apply power to the servo, it pulls the collar to the neuteral position. The collar will hardly ever actually shift into the desired gear on the first try. I believe our program called for two separate power bursts to the servo - the first to disengage the collar, and the second to mesh the other gear. Current must also be applied to the motors in between the two servo bursts in order to promote meshing. You may even want to do this 3 times. Our servo shifting routine actually ran independent of the main body of the program, so the loop times would be smaller and the duration of power to the servo was more consistent. It was pretty cool becuase everything else shut down while the shifting occured.

The shift was accurate 5 times out of 6 when the robot was at a dead stop, and 1 of 2 on the fly. Shifting on the fly with those drill trannys sounds VERY ugly, however.

Good luck with your drivetrain!

Jeff Alpert
Team 469