Bose, great job, you work really hard on this wheel.
I sujest you check out on this link where Frex´s wheel is undercover.
I hope it will help you and maybe change a little your desing using two screw ball nut. I think this is the best way to get really strong force feedback.
I on my own also working on a FFB wheel from scrach, soon i´ll post some pics.
Keep working.