Newsgroups: comp.robotics
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!ames!ads.com!pkahn
From: pkahn@ADS.COM (Philip Kahn)
Subject: What is the cheapest shaft encoder you know of?
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Sender: usenet@ads.com (USENET News)
Organization: Advanced Decision Systems
Date: Wed, 29 May 91 18:56:04 GMT
Lines: 19

I have two axes that I am controlling with steppers.  The steppers are
to be operated open loop, but I need to have some home and limit
switches. Thing is, they're a pain in the butt to mount, and it winds
up not to be so very cheap when at least 4 are required.

An easy way out of this is to find a really cheap, repeatable shaft
encoder that effectively will provide me with "multiple limit" positions.
I don't want to spend more than $10 per in quantity, they should slide
over the shaft, and I don't need good resolution (obviously), though
repeatability probably means it should be optical.  HP makes some nice
inexpensive encoders (that have great resolution), though the $25 per
is too pricey.  Any suggestions?? 

thanks,
phil...

P.S.: I don't think a pot and A/D has the repeatability I need, though
      I'm eager to be proven wrong :-)

