DocsMachine
Titanium
- Joined
- Jan 8, 2005
- Location
- Southcentral, AK
I'm in the middle of a fairly straightforward refresh of a Spanish-made Anayak Exacto vertical mill. Can't really call it a proper rebuild, I'm not scraping anything, and surprisingly little needs to be fixed. With only a few exceptions, it's really just a clean-and-paint.
You can read about my progress so far, by clicking here.
Now then, the one problem with this machine when I got it, was all three (!) of the leadscrew nuts were either badly worn, or just stripped outright. The screw itself, however, was still in surprisingly good condition- there's some minor wear, of course, but nowhere near what you'd think with the nuts being that bad.
The machine comes with a hugely overpowered power feed- it weighs about 100+ pounds, and has a 3/4HP (!) 3-phase motor. I strongly suspect some inattentive operator let the feed go past its stops, and let it keep trying to pull the leadscrew through the nuts.
As I was cleaning things out of the saddle, I kept finding half-circles of yellow metal that looked sort of like snap rings- debris of the nuts being stripped, not worn out.
Anyway, as I'm reassembling it, I decided to make a pair of new leadscrew nuts... out of black Delrin.
The nuts are fairly big- about 3" of contact to the screw, each- and adjustable:
The screw is smooth, with no appreciable galls or burrs. It does have a keyway, for the front-mounted third handwheel, but hopefully that won't be an issue.
Now, the question is, how well do you gents think those will hold up? I know people have tried Delrin nuts before, and I know injectable epoxies like Moglice are used even on big industrial machines.
I'm fairly easy on my machines, with workpieces rarely exceeding 10lb (not counting the vise or rotary table) and largely in aluminum. I expect the nuts will hold up well, with a presumed lifespan of at least a couple of years.
But, I've also never used them myself, before, and I'm curious if anyone has more direct experience concerning how long they might last. In other words, should I start shopping for some chunks of bronze right away, or can I maybe wait a while.
Doc.
You can read about my progress so far, by clicking here.
Now then, the one problem with this machine when I got it, was all three (!) of the leadscrew nuts were either badly worn, or just stripped outright. The screw itself, however, was still in surprisingly good condition- there's some minor wear, of course, but nowhere near what you'd think with the nuts being that bad.
The machine comes with a hugely overpowered power feed- it weighs about 100+ pounds, and has a 3/4HP (!) 3-phase motor. I strongly suspect some inattentive operator let the feed go past its stops, and let it keep trying to pull the leadscrew through the nuts.
As I was cleaning things out of the saddle, I kept finding half-circles of yellow metal that looked sort of like snap rings- debris of the nuts being stripped, not worn out.
Anyway, as I'm reassembling it, I decided to make a pair of new leadscrew nuts... out of black Delrin.
The nuts are fairly big- about 3" of contact to the screw, each- and adjustable:
The screw is smooth, with no appreciable galls or burrs. It does have a keyway, for the front-mounted third handwheel, but hopefully that won't be an issue.
Now, the question is, how well do you gents think those will hold up? I know people have tried Delrin nuts before, and I know injectable epoxies like Moglice are used even on big industrial machines.
I'm fairly easy on my machines, with workpieces rarely exceeding 10lb (not counting the vise or rotary table) and largely in aluminum. I expect the nuts will hold up well, with a presumed lifespan of at least a couple of years.
But, I've also never used them myself, before, and I'm curious if anyone has more direct experience concerning how long they might last. In other words, should I start shopping for some chunks of bronze right away, or can I maybe wait a while.
Doc.