The New Machine

[Rogue]

.001mm is one micron. Standard ball nuts give you 50 microns, shimmed gives you 20, the only way to get 1 is to use double nuts and spring them. Helps if you can hold the screws in tension with more springs. The Belleville washer is your friend.

By double nuts do you mean the "double ballnut" that somewhere like Zapp sells, or do you mean using two seperate nuts and combining them with the spring?

I've seen the latter in different places around the internet, but I didn't know if the former was simply a commercial version of the latter.

[Jonathan]

I'm pretty sure Robin will mean two nuts sprung, hence the Belleville washers. I think the commercial versions are just shimmed. To eliminate backlash you need them to be pushed apart using a spring applying a force greater than any cutting force plus acceleration, F=ma, you anticipate.

[Robin Hewitt]

By double nuts do you mean the "double ballnut" that somewhere like Zapp sells, or do you mean using two seperate nuts and combining them with the spring?

Either, if you use a double take the shim out