speed determination was Re: faster steppers

Alan,

A flourescent light and a print of concentric circles with different
sector ratios (black units vs. white units can get you close enough
to interpolate the 'betweeners'. Remember the ne-2 glow of turntables
and the "strobe pattern" around the disk?

Hope this helps.

Ballendo

P.S. On one site (wedemyers? or a link from/to?) there's a little
tach made of a dc motor from radio shack.

--- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi Ian,
>
> OK, that sounds like a good way. Always wanted a tach. One could
> attach a relective stripe and use a photo detector and PIC to figure
> RPM. I need to get around to that (useful on mill too)!
>
> Alan KM6VV