Greg, I followed couple of your thread and actually made some progress. I have the RPM scaling working and forward spindle rotation, but having trouble with reverse spindle rotation. Looks like in your setup you are not using reverse rotation.
I'll play with the brain some more and see if I can make it work. I might have just realized what I was doing wrong, I think Skippy, has similar setup to mine and I need to change the brain closer to his setup.