MOD1 Spur Gear query

[Ger21]

1) The larger the pinion, the smoother the motion. But as pinion size increases, you're torque (and force) will decrease. Most people use a pinion diameter of about 25mm, but bigger is actually better.

2&3 ) I've never heard of those descriptions.

4) Pinions are not really supposed to be spring loaded into the rack. It's done this way on CNC machines because it's easy, and it removes most backlash. Ideally, the rack should be mounted to a precision machined surface, parallel to the linear rails, and the pinion should be rigidly mounted at the proper depth of engagement.

If you are going to spring load it, then it should be just enough pressure to keep the pinion from jumping out of the rack. And more will just increase the rate of wear.

[marbles]

Thanks Gerry,

I think i’ll increase that pinion size from 15t to something like 30t. I would have really liked to have just mounted the pinion at the proper depth of engagement but my machining skills and equipment aren’t up to that yet. Luckily there are plenty of examples of folk using spring tensioners. I’ll just need to experiment until they seem right.