It would certainly be helpful if you could describe in a little more detail what kind of gearbox you designed. There are several methods to shifting. Most FIRST transmissions are either mesh or dog shifting mechanisms (search around the forums and whitepapers for more detailed descriptions), but there have also been ball and pin shifters that a few teams have used. I suggest surfing around the forums a bit more, and perhaps even communicating with some individual teams. You may want to investigate Team 33's 2004 4-speed mesh shifter, 45's dog shifters (or its cousins the
AndyMark shifter and
AndyMark servo shifter), 222's ball shifter, 254's (or the many teams who have adopted variants of its drive) pin shifter, or the DeWalt transmissions used by many teams (such as 469).