Threadless Ballscrew in Motion

Just another 'threadless ballscrew' 3D-printed... What I really wanted to figure out is this: How much slip does this ballscrew accumulates when travelling over the smooth rods, moving around back and forth a couple times...? Is it suitable for an open-loop design, or do you need position sensors for feedback..? Backlash is very low, which is nice.

The essential geometry of the tilted bearings was done in OpenScad, nice and customizable. The roller bearings push flat on the shaft surface. The