I have read nothing but good about Acetal nuts.

I used a product called Moglice on my Sherline and got very good results though I think an improved application technique on my part, it would be even better. The odd thing is I dont trust it. It has worked well but mentally the idea that an epoxy like substance could hold up is beyond my comprehension. I guess I will just have to test it til it breaks or til I believe in it.