[rhysun]

I've recently upgraded my old MDF, skateboard bearings and threaded rod CNC router to one that is driven by a 16mm trapezoidal leadscrew with steel nuts. However, I have severely overestimated the alignment tolerances of the axes. Even a tiny amount of misalignment causes the leadscrew to bind in the nut which stalls my puny steppers. I've managed (after many hours) to get two of the axes to play ball but my Y axis still binds. I know why it binds - poor design on my part - and there is not much I can do about it save for a radical redesign which will take months!

Anyway, I was thinking, would it make sense to get some acetal/delrin/nylon nuts made to replace the steel ones? My gut feeling is that these would be much more tolerant to misalignment than steel nuts.

[ger21]

Even acetal nuts are not very tolerant of misalignment. While probably much better than steel, they'll still bind fairly easily.

[elfrench]

Acetal nuts can wear pretty fast if the leadscrew isn't made well. I'd spend some time lapping them before adding the acetal nuts. Fortunately, acetal nuts are really easy to make and are also quite inexpensive. Try the method outlined here: Making Acetal leadscrew nuts the easy way

[rhysun]

I will 'stick' to the steel nuts for now - the binding is only an issue at higher speeds or under heavy load. I think the best strategy is to try a few hacks to get the alignment issue under control using the steel nuts and then switch to acetal. Thanks for the link elfrench! I will certainly give that method a go.

[A_Camera]

If binding due to misalignment is the problem then fix that and not try hiding it. Acetal (POM) is better than steel as leadscrew but the solution is not changing the nut or lubrication but solving the cause of binding.