On 2010-12-18, Wild_Bill wrote:
Wouldn't a low number of counts.. 100 counts (1 = 1%), or 360 (1 = 1 degree)
be adequate for the rotational position of a tap?

I suspect that 100 counts would be far more reliable at high (or low)
speeds, even though HSM tapping isn't an especially high speed application.

Assuming the 4096 encoder was already purchased, it would work to test the
application, but there isn't really a need for that high of a count per
rotation, is there?

I have a US digital encoder. The encoder disc that provides pulses is
replaceable and is not very expensive, whatever it is, $10-20 or so.

Replacing the disc is easy and cheap. Mine is 1024 pulses (4096
counts). Very possibly, a lower count would work even better, say 500
counts, and could let me tap at high speed.

At this point, tapping at 500 RPM is just fine with me and I do not
feel that my needs would be served better if I could tap at 4,000 or
even 1,000 RPM. In fact, to do motor reversals with the VFD, at high
speed, is kind of taxing and I overshoot the tap position a lot. And
at 500 RPM, my encoder works fine, as evidenced by my trial today.

i