RE: [CAD_CAM_EDM_DRO] Digest Number 2937 - Steps per inch

You have a problem that you need to track down. Sherline screws are very
accurate at 20 tpi.

Tim
[Denver, CO]
Sherline products at Deep Discount
Mach1 & DeskCNC with credit card ordering
www.KTMarketing.com/Sherline
Now selling Visual Mill

> -----Original Message-----
>
> In following the discussion on calculation vs. trial and
> error setting of the spi I would like to relate my experience
> and ask if it makes sense or is way out of line.
>
> I initially set the spi by calculation; sherline supplied
> standard lead screws 20 tpi X 200 steps per motor revolution
> X 4x stepping equals 16000 steps per inch, Correct?
>
> However when I measured the travel (at several places along
> the axis) using MDI commands my dial indicator repeatedly
> indicated that 16070 steps were necessary to get 1 inch of
> travel. Similar experience (slightly different
> numbers) on the other axis. Does this sound reasonable or do
> I have something to track down? And what might it be?
>
> PJH
>
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html