My spinner sucked, and i assumed this is why i never used it. I ordered an intelligently engineered one from Oscarcontrols.com.
I got the Mark 1 with alum knob and axis switching. I was planning to also hookup a button to switch axis back and forth, a poor man's trackball, but not that simple
My cats love to get inside the mame cabinet and chew on wires, etc. They must have unpluged the oscar spinner's optical board from the mouse interface a
couple hundred times before the unavoidable happened, i plugged the IR detector into the emitter plug! BZZZT, by by IR detector! UGH!
Fortunately i still had my lame spinnder (below) laying around, i unsoldered the IR detector and put it in place of the oscar one. The detectors
are labeled "EL" on top (got me) the "E" seemed to be + (the red wire went to it) and the lead coming out for the "E" was thinner then the "L", i just
made sure to match them up and SUCCESS!
You can see the detector on the second picture below, its a little black box with "EL" stamped into it.
Spinner - I wanted a little spinner for Discs Of Tron, etc

I never really use the spinner, it was kinda a waste of time to build one, but oh well
I'd recommend adding the spinner last since you may end up not even wanting one

Dave + lpad(aka volume knob) + joystick extender for metal control panels + mouse + stave(aka pc slot cover) = spinner!

But how do you make those parts co-exist? LOTS OF HOTMELT!