I want to turn a 4" OD x 3/8" thick gear 80 to 110 degrees in 100 ms. I'm thinking of a 4" stroke by 1-1/4" bore air cylinder attached to a rack gear that would engage the round gear. No, I won't do it with a servo! I'm thinking a1/2" round rack gear in a tube with Thomson linear bearings and a scallop cut in the middle of the tube to expose teeth to the round gear. This seems simple and cheap. In fact, it's so simple it would seem that it should be an off-the-shelf item! I just assume it would be easier to do with round rack than square rack. Is this available or did I invent a new wheel?
The gear would just spin back and forth and the air cylinder/rack will have an adjustable stop to get my 80 to 100 degrees rotation. The round gear will have a one-way clutch installed because I only want the one direction of shaft rotation. The shaft will power a wire feed mechanism to feed 3" to 3-1/4" of wire.