Quote Originally Posted by russell View Post
To keep the costs low I intend to start with the original leadscrews and replace the nuts with homemade anti-backlash acetal nuts.
I'd be wary of acetal. A much better solution is what I tried here:

http://www.youtube.com/watch?v=m6k8J...Gs_IoRUuanN2U=

Cheap, less backlash, durable. You'll probably want to use 4 bearings, like \/\/ for better rigidity and to cancel out the torque each bearing imposes on the screw.