Thanks.
It was really simple.
I got the idea from this website:
http://www.arcadecontrols.com/files/Miscellaneous/spinner.pdfWhat you do is print an encoder template on a sheet of paper, glue the template on to a piece of sheetmetal, & then cut it out with a band saw or just invert your jigsaw like I did.
Use a bench grinder to dress the edges.
There is a printable template available Nathan's pdf (above).
The one on his tutorial was made with plastic, but I prefered the weight gained by using metal.
I made one encoder (on the left) using his template but then I decided that I wanted more sensitivity so I had a friend make a new template up with more spokes using Autocad.
I will soon be making a couple more with differnt spoke amouts to try to get the best feel, hence the "test bed" comment.
Of couse I could always adjust sensitivity in the setting menu but I like to tweak.
Another great site with lots of info on the shafts, bearings & other hardware to use was:
http://www.gearheadlabs.com/spinner/With the weight of the flywheels & encoder wheels, these things really spin freely.
I used the Spinner Roundup video to compare the spin times & I'm pretty happy with the results to say the least.
Hope this helps.
Z