Bosch Pinion

[Andy Baker]

Originally posted by Andy Baker
Oh, phooey on that gear... our team has decided to take the gear off and put on one that fits our geartrain better. I hope that a tight press fit works.

Andy B.

OK... we just took off that drill pinion today and put on a new pinion that was a 32 dp gear. After ruining one motor (bent the shaft a bit - too tight ID at press), we had some success in putting this new gear on.

Our new gear had a purchased ID or 0.187". First, this gear was drilled out with a 0.189" dia drill, and then a 0.191" dia drill. I'm guessing that this gives us an ID of 0.192" or 0.193" (we don't really have a precice way to measure this).

At this point, the gear presses nicely onto the drill's 4.99-5.00mm shaft. We are estimating that this provides a ~0.003"-0.004" press fit, which should be plenty tight in order for it to stay in place (no welding or pinning needed).

It "feels" right so far, but we won't know if it's right until it's put under a load.

Andy B.