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From: tonyo@sagerat.CNA.TEK.COM (Tony Ozrelic)
Newsgroups: comp.robotics
Subject: Re: What is the cheapest shaft encoder you know of?
Message-ID: <1394@masterCNA.TEK.COM>
Date: 17 Jun 91 19:06:24 GMT
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Reply-To: tonyo@sagerat.CNA.TEK.COM (Tony Ozrelic)
Organization: Tektronix, Inc., Beaverton,  OR.
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Regarding cheap shaft encoders:

The Do-It-Yourself Type:

Make a small plastic disk, about 2 inches in diameter. Paint one half of the
disk black, leave the other half clear, or glue aluminum foil to it
(for reflective sensors). Position 2 optical sensors at 90 degrees to each
other. The outputs will give you 4 pulses per rev after decoding. Mount
on shaft of motor by drilling hole in center just a tad (smidge, in the metric
system) smaller and force-fitting the disk onto the shaft. A drop of super
glue does the rest.


The Cheap-Off-The-Shelf Type:

Buy a Bourns Optical Encoder from Digi-Key. For $25 you can get a
128-pulses-per rev encoder.


Decoding the outputs is left as an exercise for the student :-)

tony "i hate it when he says that" o.