HIWIN offers JPG's with full dimensions for their screws on their website as well as lead specs of rolled vs ground. Call them at their office (phone is on the website) and ask for tech support. I got thru to an engineer at first call and he didn't have me jumping thru hoops.
For backlash, simply install true, machine tool grade ball screw support bearings. Pricey but well worth it. You do have to make some shims but it is easily done with some lazer cut shim stock (oem BPT bearings are oddball width) but easy to deal with.
We've got nearly 0.000 baclash comps and measure roughly a net 0.0001 "blip" at direction changes when outside circle cutting. We we measure the deviation with our cam measurement equipment
Our screws are OEM supplied rolled threads from HIWIN on a BPT "EXTRAK". Briian at BPT Machine in Carol Stream Ill did the servo tuning. |