Leadscrew

[fusionkid]

Thanks guys, by resolution you mean what measurement divisions "on the dial" so to speak?
Well because of the purpose i don't think measurement is critical, i'm building a recording lathe (that records are made on). The cutter carriage has fixed start and end points for the cutting range other than that the actual measurement i don't think is critical. So the answer is i don't know!! But the feed rate must be down to about 2mm/min. Are there methods for working out what i need?
I posted a pic of a commercial recording lathe in another post here:http://www.mycncuk.com/forums/showth...siastic-Newbie

[Jonathan]

Thanks guys, by resolution you mean what measurement divisions "on the dial" so to speak?

Yes.

With the low feedrate you're after clearly the problem is getting it to run 'smoothly', i.e there needs to still be a highish step rate. I think you could achieve this in two ways. Either gear the stepper motor down with a timing belt and pulleys, or use a high microstepping division. The latter wont help with resolution but it can get the motor running very smoothly.

[FatFreddie]

Ah, that changes things. Normally a stepper motor would be used as it's easy to set the feed on but you need a continuous feed not a stepped one (otherwise you will hear each step). How many revolutions do you get on a record? Is it the same spacing all over? Do you need to vary the spacing (IIRC there is a trade off on the groove width between quality and run time).