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Unread 15-12-2009, 16:48
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FRC #1197 (Torbots)
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Re: combo encoder and chain tensioner

Quote:
Originally Posted by stj_1533 View Post
Hi folks,

The last few years we've always seemed to mount our quadrature shaft encoders somewhere difficult to reach. I was thinking that this year we'd try to mount one with an idler sprocket on a chain tensioner. Any thoughts?

- Steve
Use caution. If the encoders don't like side loading, you'll need to support the other end.

However, I have another suggestion that's worked before. You'll need, in addition to the encoder, sprocket, and encoder mounts:
--an axle of appropriate size for your sprocket
--A pair of mounts that allow the axle to be moved side to side as needed to tension the chain. (Could also be up and down.)
--a piece of surgical tubing and a pair of zipties.

The best picture I can find of this method is at http://www.chiefdelphi.com/media/photos/27675. If you can zoom in right in front of the close tranny, you'll see a small metallic boxy thing with a sprocket on it. The other end of the sprocket's shaft has been machined down to the size of an encoder shaft, and the encoder is on the other side of the holding metal. The encoder shaft is flush against the axle's end, and surgical tubing is used as a sleeve to keep them together (after being stretched a little and ziptied down).
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2003-2007: FRC0330 BeachBots
2008: FRC1135 Shmoebotics
2012: FRC4046 Schroedinger's Dragons

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