On Fri, 05 Oct 2007 12:53:27 GMT, Anthony
wrote:

Rich Grise wrote in newsan.2007.10.04.23.14.10.688248
:

Drill a bolt hole pattern in the outer edge of the flywheel and use a fiber
optic beam-thru sensor. It will be a _much_ more reliable set-up. Optical
retro-reflective sensors are prone to false sensing.

some fiber optic sensor manufacturers
www.bannerengineering.com
www.keyence.com
www.balluff.com

But in any case, watch out for the response time of the sensor. The
hole (or flag) needs to be large enough to give the sensor time to
trigger. If something faster than the packaged sensors above is
required, bare emitter/sensor pairs are available that are at least a
couple orders of magnitude faster. Of course, you then need to build
your own signal conditioning, but that's not very difficult.

--
Ned Simmons