SFU1605 Ballscrew Standard vs Anti-backlash

[Voicecoil]

Ballnuts (assuming they're of reasonable quality) on a ballscrew inherently have very low backlash. Since they work on a rolling rather than sliding concept they can have close tolerances and low friction, something that's not really possible with a lead screw.

[JAZZCNC]

Hi James,

Well, my first advice is to tell you to stop buying stuff before you know what you need. Because already you have made a bad choice by buying a 5mm pitch screw for a machine this size and application.
With 5mm pitch, you will struggle to get the feeds you'll require to cut correctly also if the screw is for the long axis this will be compounded because the length will cause whip at higher rpm's unless it's 25 or 32mm ball screw, which I doubt it is, plus large screws will introduce other issues regards motors, etc.

The better pitch for a machine this length and application would be at least 10mm with a minimum diameter of 20mm. 16 or 20mm pitch would be a better choice as it allows for ways to deal with the whip and still have the correct speed for the feeds required to cut correctly.

Regards the Antibacklash nuts then don't worry about it because while they are not Zero backlash they are still very low and far better than is required for any DIY machine cutting woods, plastics, and light aluminum work.
Also, I'd forget fitting another ball nut at a later date to cheap Chinese screws as no two screws will ever be the same and you'll end up messing about trying to preload the backlash out with oversize balls, etc. You'd be better off buying the screws from the start with double nuts which are already preloaded.