Lathe Chuck Lubrication

[great white]

At the risk of seeming inexperienced ( I am), would it be plausible to coat the scrolls with a graphite spray that dries to lubricate the loaded surfaces, without the tendency to attract chips and whatnot?

I’ve used that before. Seemed like acceptable performance afterwards to me.

 

[Red96]

Personally, I love the stuff. Especially useful in locks and the ratty mechanisms on ratchet-straps.

 

[Nesse1]

And now, the rest of the story...

My chuck was binding and didn't want to close down all the way. I thought is was an issue of lubrication, and maybe some burrs. Took it apart, cleaned everything well, then did a dry fit and found a couple of the jaws were not sliding smoothly in their grooves in the chuck body. The jaws are numbered, but there are no numbers on the chuck body, so it was trial and error figuring out where they belong. Interestingly, the jaws only fit one way; jaw 1 slides smoothly in one groove, but doesn't slide in the other two. To improve sliding I took a small file and deburred all the edges. That fixed jaw 2, but 3 was still binding. More filing, and it got better. Next, a touch of lapping paste, working the jaw back and forth in the groove got it into decent, but not perfect shape. I washed everything, again, and I'll take one more look at everything and then assemble. I'm going to use a light coat of lithium grease. Wish me luck...

 

[Huub Buis]

In the inside of the chuck, I use grease.
I have used graphite on my 160 mm chuck claws for 2 years but switched back to grease because the graphite gives such a mess when changing the claws. Oil is a no go (for me) because it comes out pretty fast.
My 80 mm chuck, the claws are always used dry.

 

[RJSakowski]

None of my chucks are sealed against machining swarf. Chips will find their way into the interior causing jamming and wear. I lightly oil the scroll and jaws on reassembly to provide some lubricaton and prevent any rusting. Aside from that, the oil used for machining provides necessary lubrication.

 

[Dabbler]

I usually defer to manufacturers recommendations, but personally, I don’t like the thought of grease on equipment that will be in a “chip heavy” environment.

I'm going to use a light coat of lithium grease.

I have 2 chucks I've used for 40+ years and only needed servicing once in that time.

I am also in Renzetti's camp, but I happened to use bicycle lithium grease, applied with an acid brush so lightly it just 'clouded' the bright finish. When I serviced it after 20+years of use, there were a few loose chips inside (inevitable), but nothing stuck to the scroll or pinions. After 20+ years, the grease dried out (of course) and I re-greased it.

The proof of the pudding: the jaws are friction fit in both chucks - Taiwanese made and delivered as friction fit. So no serious wear in perhaps 1000 hours of use, each. I just bought a used lathe, and that is what I intend to do when rebuilding those chucks.

 

[ChazzC]

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Interesting video; a couple of thoughts:

• This has to be the cleanest chuck I have ever seen, even out of the box: no protective coating, no oil, no grease and nothing to indicate that it has ever seen any use.
  
  
• They are very heavy-handed with the grease, even leaving visible gobs of it after the process is complete.
  
  
• Recommended partial disassembly, cleaning & greasing every week?
  
  
• And the final recommendation to use machine oil for "heavy operating conditions."

If you use the amount of grease they show, you would need to clean a chuck every week. I'll check the next time I see him, but I doubt if my local one-man shop who's operated his own shop for most of his life has ever disassembled a chuck unless it was giving him problems. And if he did it once a week, he'd have to work every Saturday just on maintenance.

Several companies I worked for had full-fledged machine shops (back in the day before they were aligned with local shops for their needs), including building production equipment (they also had full engineering & design staffs). At the rates they were paying their machinists & mechanics, they only fixed things when they were broken and never seemed to have any problems.

As hobbyists, I think the recommendations would be:

• Disassemble, clean and lightly lubricate with grease when a chuck s first placed into service (new or used).
  
  
• Keep the chuck clean (don't use air).
  
  
• Clean and maintain a chuck if you notice any change in its performance/operation.
  
  
• Perform a full disassembly, cleaning & lubrication every 2 – 3 years, depending on how heavy you use the chuck (and if you keep it clean after use).

 

[Nesse1]

I've got the chuck back together, and it's working better than before. There was a nasty burr on one of the jaw teeth, and after smoothing that over, the chuck now closes down all the way. It's not a particularly smooth chuck, but serviceable. I had to dress down the ID of the scroll gear with a dremel, because I couldn't get it into the chuck body without binding. Again, I used lithium grease, lightly, during assembly, but I won't likely pull this thing back apart unless it's getting crunchy in the future. To be honest, I started searching eBay for something better. I don't want to spend more than $400, though. Are their any "better" asian chucks, that can be had for a decent price, or do I need to go the "semi-steel" Bison, or similar, route?

 

[Dabbler]

One more word, on all this chuck stuff: In November a friend and I rebuilt a 14" Rohm chuck - 50+ years old, very heavy use, coolant used in most of its operation.

The pinions were heavily rusted (coolant) but the scroll wasn't too bad - just a few pits, but mostly shiny. The gear side was heavily rusted from thousands of hours of coolant, and -- not once -- ever taken apart and maintained. We wire brushed it, stoned a few burrs, coated every surface with grease, and put it back in service. It still holds to .0005 at 1" and .001 at 2". Yes the pinions feel a little lose, and I wouldn't use a big cheater on the chuck key. but it works just fine.

So if your scroll chuck feels feels even a little "wrong" THAT is the time to disassemble, clean and re-lubricate your chuck. It isn't hard. The hardest part is recentering your chuck - and that is good practice anyway!

 

[Nesse1]

The hardest part is recentering your chuck - and that is good practice anyway!

What is "recentering"? Yes, I'm a newbie!