Re: [CAD_CAM_EDM_DRO] Ballscrew lead question

Hi David,

The pitch of the ballscrews has little effect on their accuracy.
Acccuracy is dependent on how accurately they are machined. Backlash
does tend to increase slightly when you get to the really coarse pitches
like 1TPI and less.

Metric pitches aren't odd - those strange inch pitches, now they are odd
;-). It actually makes no difference to TurboCNC,EMC, Mach2, DeskCNC etc
if your screws are metric or inch. They all generate a scale factor that
translates your machining units to steps. This scale factor is only
calculated when you are setting up so it makes no difference when you
are cutting.

Les

volitan712003 wrote:

> I'm finally ready to buy my ballscrews and nuts.
>
> My question is about screw lead versus machine accuracy and
> repeatability. I'm seeing a lot of surplus ballscrews available lately
> with a .250" lead (4 turns per inch). Considering that I'm going to
> gear down with pulleys anyway, is this pitch OK or am I better off
> waiting for a the rare .200" ones that come around every so often?
>
> Also, if I see some metric screw where the size is perfect, but with a
> metric pitch... Is TurboCNC and/or EMC able to handle odd pitches like
> this and not choke doing the math while interpolating?
>
> Thanks
> David
>
> P.S. - I have a Bridgeport clone (actually a little smaller) and I'd
> like it to repeat to at least to .001", and I don't care if my rapids
> are not blazingly fast.
>
>
>
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