Low Friction Potentiometer

LarryCardo

I am building a bot to balance a pole. I had planned on using the accelerometer (MX2125) to determine tilt angle, but it is far too sensitive to vibration. I tried to soft mount it to no significant effect. My thought now is to use a potentiometer across a voltage source and a A/D converter. I purchased a Radio Shack pot, but the resistance to move the shaft is considerable. I do not want the expense nor complexity of an encoder.

Any suggestions for a low friction pot?

DaveG

Larry,

Several years ago I built pole-balancing robot and entered it in a Parallax SX Design contest.
Here's the address: http://www.parallax.com/sx/contest/contest_balancing_robot.asp
You might take a look at the schematic and writeup.

At first I tried a low friction potentiometer that was specifically designed to be used for pendulum measurements.
It was a Model DT031 Sensor from fourier-sys.com, however it does not appear to be available any longer?

I spent a considerable amount of effort characterizing the DT031 and found that it was a little noisy and the resolution
wasn't all that good, especially for small angles. I ended up building a simple, low-noise optical angular sensor,
which worked great.

Dave