pic: Mr. Cellophane

[Nuttyman54]

The shooter wheel is actually a 2" roller mounted directly one a CIM. It's hidden by a piece of pressboard mounted about on ball-length from the first ball in the queue. The purpose of the shooter is to allow us to get them into the corner goals w/o having to drive all the way up to them. It hasn't been mounted yet, but we hope to add an IR distance sensor to automatically adjust the wheel speed and get the shots in. We tested with a 1/2 width plywood goal and made 11/13 shots within 3 seconds

As for the transmission, it was orignally designed for the drill motors, so we did some pre- and post-gearing on it to get it back down to reasonable speeds. The CIM you see next to it is geared 1:2 into the transmission input, then geared 1:2 to a stepper shaft mounted above the wheels, and then 1:3 to the wheels. The We got the automatic shifting to work using a 4-slot home-made encoder wheel (mounted on the output shaft). We found the intersection points of the efficency curves (from 33's excellent white paper) for the different gears and applied a histeresis to keep them from shifting too quickly. It will also never go past 3rd gear unless the driver holds both triggers and forces 4th gear.