Quote:
Originally Posted by team 888
I went over the final design robot this morning and the drive train is in the way for placing the potentiometer.
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If I had a dollar for every time this has happened... Too many times the sensors get added in as an afterthought.
You won't get anything useful from the OI, you need feedback from the actual rotating turret to have a real control loop. Anything else is just open-loop control and prayer.
Methods for retrofitting some sort of feedback sensor include:
1. The abovementioned technique of adding a gear to the turning shaft, and hook a pot or encoder to that shaft.
2. Similarly, Team 95 has used friction wheels against the turning shaft. I don't recommend this, since it almost always will have a bit of slip.
3. Depending on the shaft size, you might be able to put a gear or nubs on it and use the Gear Tooth Sensor (note that with just one sensor, you won't be able to tell direction of rotation).
4. You can get shaft encoders that slip over an existing shaft, but you might have trouble procuring these in time.
5. I've seen string potentiometers (both professional and jury-rigged) used in all sorts of interesting setups where nothing else fit, if you can find or make one in time.