Urgent advice needed on warped ball screw!

Hi
I made the mistake of ordering some parts from China including 2 1605 ball screws. I have just rolled them both across a perfectly flat granite slab and whilst one is perfect the other one is about 1mm out of true.
These are for supporting the bed (Z-axis) and will be paired with 2 20mm linear rails. Do you think this is enough distortion to be a problem? I dont have much time to file for a refund!





Edited 1 time(s). Last edit at 01/22/2018 07:34AM by SplatHammer.

Slightly bent ball-screws are a somewhat common occurrence. It is not normally an issue In CNC milling machines and routers because the surrounding components are rigid.

You can straighten screws fairly easily with the correct tools. Some cloths, v-blocks, and an arbor press is the best option. Otherwise a vise plus a cheater bar (aluminum tube to go over the screw and use as leverage) does okay.

Mark the bend with a sharpie and go slowly.

Thanks for the advice! Unfortunately I dont have the right tools, I will try 2 blocks of wood andtry doing it by hand. Or since the seller is a complete knob and didnt bother using ANY packing at all for 5 linear rails and 2 ball screws I think I will just go for a refund! believe it or not 2 of the linear rails didnt move, when I check them I found the ball bearings were SUPERGLUED in place and couldnt move. Seller claims it is my fault! Just bought some nice H grade HiWin rails to replace the crap from China.