HDPE acme nut

[Rickv100]

I built some acme nuts out of HDPE for my JGRO router and they seem to have a good amount of drag in use.

Any suggestions on lapping or other methods to reduce the drag?

I can turn the acme rod with a wrench on an acme nut but there is a good amount of resistance.

Rick

[Geof]

Did you tap these nuts the way I have seen described by using a piec of the threaded rod?

HDPE is flexible and even with a regular tap tends to 'flow' around the cutting edge so the thread comes out a bit small.

One thing you can try is put the nuts and tap in a deep freeze to get them as cold as possible and then retap the thread. The HDPE will contract much more than the metal and will become a bit more rigid so there is a good chance a bit more will be cut out. It will still be tight at the low temperature but once it warms up shold be looser.

[Rickv100]

Yes and no, I did tap the HDPE using a piece of Acme rod made into a tap but I did not freeze them prior to tapping, I will give that a try.

Rick