Ballscrew or leave alone?

[russell]

Delrin will have reduced friction But I found that it just acted as a damper and masked the backlash. measuring low backlash only under a no-load condition. Once the load is applied it compresses until the the other edge of the screw is in contact( ie play in the screw/nut). The amount of compression is dependant on the load so you end up with varying amounts of error on the work piece.

Agreed, this can be a problem but like everything it depends on the design. Some use springs to compress the split nut and of course these flex under load. I am just using screws to adjust it with no flexibility. My first attempt did have a flexibility problem which I traced to the flange on the nut flexing. It was cured by backing it with a substantial steel washer.

Again, horses for courses.

Russell.