Very detailed technical info
http://www.heidenhain.com/wcmsmimefi...3_20_15180.pdf
Unfortunately very expensive scale
I am looking for much cheaper (same precision)
there is some kits very interisting
I have made a roller screw for my lathe my backslash is 4/100 mm this backslash mean 3.6 degres on my screw not a big deal to stabilize and avoid hunting effect.
it is a chinese lathe i am sure that i can compensate with linear encoder
backslash is the main