On Fri, 17 Dec 2010 23:07:38 -0600, Ignoramus30138
wrote:


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.

You can't replace just the disc. The pickup has a mask in front of the
sensors that matches the pitch of the lines on the disc. The sensor
does not sense the passing of the individual lines on the disc -- it
picks up light and dark transitions that result from the interference
between the disc and mask.


--
Ned Simmons