1/2" Shaft Encoders

[DavidGitz]

Originally Posted by CrazyCarl461

Was the hole put in the end of the shaft using a lathe? Any other method will never be straight enough to work.

Is this a "rule of thumb" or have you actually seen that without using some sort of precision rotation method to change the diameter that even a small angle offset will result in the behavior I described?

Originally Posted by CrazyCarl461

If it is a joint on an arm in the classic sense, then it may be better suited for a potentiometer anyway. The optical encoders are better for continuous rotation applications like drive wheels.

Potentiometers are usually easy to get at places like Radio Shack. Plus, it has the added advantage of knowing the absolute position of the arm at all times instead of the relative position.

They are easy to mount too, make a little bracket for them and then our team sometimes uses what we call the "Cyber Blue method" where we stretch a very short bit of surgical tubing over each end to act as a flexible coupler.

Wire it up to an analog input and you are done!

We have used potentiometers before. I am normally more of a fan of the encoders as they can deal with being overdriven and are not noisy, but these are fairly limited justifications as you can easily get a multi-turn pot and the aren't the analog inputs aren't that bad. We used encoders more just because they were readily available. We ended up just using timing and within about 3 hours had our autonomous program running completely successfully so we will be going with an open-loop control system, as referenced here: http://www.chiefdelphi.com/forums/sh...threadid=91793