Best anti friction additive for epoxy - (for mill leadscrew nuts)
Best anti friction additive for epoxy - (for mill leadscrew nuts)
(OP)
I would like some suggestions on a good anti friction additive to epoxy. I will replace my hobby mill's brass leadscrew nut with a 'cast in place' nut directly on the leadscrew. This is not a new idea. It is a very effective easy way to virtually eliminate backlash.
I've read that graphite powder is good but can be hard and therefore may cause wearing. Molybdenum is better but hard to find. Fine aluminium oxide can be good too.
Interested in info regarding additives, suggested epoxy/additive ratios and hopefully suppliers too!
Many thanks.
I've read that graphite powder is good but can be hard and therefore may cause wearing. Molybdenum is better but hard to find. Fine aluminium oxide can be good too.
Interested in info regarding additives, suggested epoxy/additive ratios and hopefully suppliers too!
Many thanks.





RE: Best anti friction additive for epoxy - (for mill leadscrew nuts)
How about a split nut made of Teflon, with a pinch bolt?
Or a brass nut, and a brass locknut, locked together by an axial setscrew?
Or a brass housing like a plug valve body, filled with Teflon? You can tap the Teflon if you like, or just leave a clearance hole. Put a threaded plug in the open end, and use a big wrench on it to compress the Teflon. It's amazing how much you can distort the stuff, plastically.
Mike Halloran
Pembroke Pines, FL, USA
RE: Best anti friction additive for epoxy - (for mill leadscrew nuts)
I would look to use BN (Boron Nitride Powder) as a lubricant. Another possibility is Colloidal or Micronized Graphite.
ht
Backlash:
My father once worked on a machine similar to a ruling engine where the lead nut was a leather pad clamped around the screw. He told me that this evened out any imperfection of the lead screw and eliminated backlash.
RE: Best anti friction additive for epoxy - (for mill leadscrew nuts)
You could add fine PTFE powder (as already mentioned) or add a fluoroepoxy that polymerises in. These must exist as I have seen them used for anti-graffiti paints. Adding some kind of silicone should also work. You can get the PTFE powder in an aerosol spray can from RS Components for example to try it out.
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- James Branch Cabell
RE: Best anti friction additive for epoxy - (for mill leadscrew nuts)
ICI used to make a grade called Fluon L169. I have no idea if it is available now.
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RE: Best anti friction additive for epoxy - (for mill leadscrew nuts)
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Could be same but in small quantities....
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....getting interesting.
RE: Best anti friction additive for epoxy - (for mill leadscrew nuts)
If so I think it should work at about 10 to 20% add rate.
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