RE: [CAD_CAM_EDM_DRO] positional resolution

The vendor is giving you a figure based upon half stepping (400 steps
per rev).

There has been much discussion as to how accurate a microstep actually
is positionally. I think the best answer is that your calculation is
correct under some circumstances, but that it may not be that accurate
under others. Real world results would tend to indicate that friction,
lash, resonance, windup, etc will not allow a step to consistently be
.000025" on most equipment.

Tim
[Denver, CO]

> -----Original Message-----
>
>
> Hi
>
> A leadscrew with 20tpi and 200step/rev should have a positional
> resolution of 1/(20x200) = 0.00025 in.
>
> Have I missed something in the above calculation because I read on
> the website of a system vendor listing the positional resolution as
> 0.000125 in.
>
> Further, if in the above example, one uses 10x microstepping, is it
> presumptous to claim a positional resolution of 0.000025in?
>
> Many thanks
>
> Peter
>
>
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/