The ball screw fit for the linear guide

I spent a long time to decide, should I make a whole new XYZ machine, or upgrade my Delta(cause I dont like delta very much, hard to adjust,not very very accurate=.=). And at last, one of my friend made linear guide version delta with three ball screw pairs~seems good.

Then, I designed this~~a ball screw fit for the linear guide~

I planed to use the 1204 screw, though 4mm maybe too short, but my stepper motors are 1.8degree/step, that's 200steps/round, means 0.02mm/step~and I use the 1/16