Quote:
Originally Posted by martin417
Sounds like way more motor than necessary. We are using a custom 6" diameter polycarbonate wheel with 10" polycarbonate flanges on the sides. We are spinning it with a single FP 0673 using a BB Cimulator and further reducing through a belt drive for a final ratio of about 4.1:1. We spin the wheel anywhere from ~2200 RPM for close up shots to ~3300 RPM to shoot from the barrier. We have no problems spinning up quickly and maintaining speed, nor shooting rapidly.
By the way, A PID is over kill for this application. The system has enough inertia that speed changes slowly (in the computer sense of slowly) so there are better ways to control the speed than a PID.
As for tread, we covered the polycarb wheel with self adhesive rubber foam. It does wear away with use, but does not damage the ball.
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Top and bottom wheels? Or just bottom wheels?
Sounds like we are using similar shooting speeds though I wonder why yours is going a bit faster. We do have a bit too much power, the motors are always cool to the touch. PID control is a quick and easy way to make sure the wheel is rotating at the correct speed (for different distance shots since our launch angle is constant). And the PID will give the ball a little extra juice when shooting (no slow down at all). Wheel speed is critical for accuracy, correct? How do you do it - assume the wheel speed for a given PWM setting? That will change as your batteries discharge!
But the thread is really about the wheel surface - did you try any other surfaces?
TIA