Been Noticing Something About My Chuck

[JoeLee]

I would take it completely to bits and degrease everything. Look closely for anything stuck on where it shouldn't be, and try out the master jaws in their respective slots for smooth movement. The screws which hold the 3 pinions in the body should not be tightened, but left loose, they cannot fall out, but can cause problems. Just screw them in underflush of the body. You could use grease on the scroll bearing and pinion teeth and pinion bearing bores, but only oil on the scroll and jaw slots. Check that there are lining up marks on the 3 parts of the body, so they go back together the same. 12 years without proper cleaning is a long time, and your chuck looks like new, I would strip one down every few months to get the swarf out, and an airline will not do.

I don't think there are any alignment marks unless I made a small almost undetectable scribe mark somewhere the last time I took it apart.
I agree 12 years is a long time to go without greasing the internals. But I bought that chuck in the early 90's and the first time I opened it up was in 2010 and I really didn't have to even do that.
It was spotless inside and the grease was still there. The factory was pretty stingy with it too.

JL..............

[JoeLee]

I grease mine but only with a very thin film. Like I pick up a little grease on an old toothbrush and spread it around like it costs serious cash. The hope is that it will lube the workings well but won't catch and hold too much of the swarf. And at the same time not decorating the lathe, back panel and me in a line of lube like oil will do.

It's been more years than I want to admit since I had my own chuck apart for cleaning and for sure I can feel chips in the scrolls that need to be "bumped" out of the way with some back and forth now and then. But it's never caused the tight to release issue like you're describing. I think it's time for opening it up again to get a look at what is going on.

One possible cause that occurs to me is that the inside plate that holds the scroll in position might have come loose and backed off. If so then the scroll might be wedging it self back against the pinions and causing them to feel tight for the release. That's just a shot in the dark though.

Unless it's something that has come loose and is causing the wear I can't imagine that it's worn into this failure mode. At least not unless it's seeing constant daily use in a full on working environment of a proper working shop. We HSM'ers simply don't spend long enough in the shops to even come close to making the machines work as long and hard as a full on commercial shop.

Very sweet looking Clausing you got there.

I don't think there is a plate in there like your describing. From what I remember the scroll sits in the body and the jaw part of the chuck presses over it. The pinions look like these......
https://www.toolmex.com/catsearch/29...-scroll-chucks

I don't think there is anything that can come loose in there.

JL...............

[JoeLee]

This is the grease I have. I bought the small tub back in 2010 when I first took it apart.
Tool Mex just sent me the cartridge. They both have the same part number but are different colors. I'm going to have to guess that the tube is a newer perhaps better compound ??





JL.................

[J Tiers]

I've never seen any plate either, in any chuck, and I have about 5 or 6 different brand chucks, several of which are good ones..

Grease is likely OK for the pinion side. Not for the jaw side, unless in the sort of trace amount mentioned.

The "one-way clutch" behavior is a little odd. But chips can get wedged in a way that something similar can happen.

[Richard P Wilson]

When the OP says 'plate' presumably he means what is revealed when the chuck is taken off the backplate. Its usually held in place with 3 small screws, take them out, take the 'plate' out, and the pinions and nack of the scroll are revealed.
Just to eliminate something, does the chuck do this jamming when the other set of jaws are used?

[oxford]

This is the grease I have. I bought the small tub back in 2010 when I first took it apart.
Tool Mex just sent me the cartridge. They both have the same part number but are different colors. I'm going to have to guess that the tube is a newer perhaps better compound ??





JL.................

Those are 2 different part numbers. One comes back as “Bison” branded and one is “TMX” branded.

[Toolguy]

With dry chucks, I clean them about once a month. It's a 10 minute job to pull the jaws, clean them with a chip brush, Blow out the scroll area while turning it with the chuck key and put it back together.

[JoeLee]

When the OP says 'plate' presumably he means what is revealed when the chuck is taken off the backplate. Its usually held in place with 3 small screws, take them out, take the 'plate' out, and the pinions and nack of the scroll are revealed.
Just to eliminate something, does the chuck do this jamming when the other set of jaws are used?

What do you mean the other set of jaws ? I don't have another set.

JL...............

[JoeLee]

With dry chucks, I clean them about once a month. It's a 10 minute job to pull the jaws, clean them with a chip brush, Blow out the scroll area while turning it with the chuck key and put it back together.

I take the jaws out once a year and clean the scroll and jaw teeth. It's not a big deal and I've never found much swarf in the jaw slots or in the scroll.
All the chips and fine particles seem to stay in front of the jaw screw and stuck to the grease that the jaw has pusher forward. The grease kind of acts like a seal to prevent swarf from getting into the teeth.
When I take this apart I'll post some pics of my findings.

JL................

[JoeLee]

Those are 2 different part numbers. One comes back as “Bison” branded and one is “TMX” branded.

Yes, this is true. Bison is now a separate company from Tool Mex so I guess they each have their own grease. Not sure what the difference is other than the color.
I spoke to the Bison rep and he didn't know either but thought that the Tool Mex brand may be slightly softer or less stiff than the Bison.
Both part numbers are the same except for the first number one being 7, and the other being "3" but I don't know what that number designates.
Bison made their own grease in Poland... so says the label and TMX has their grease made by some US company to their specs I would imagine.

JL.................

[oxford]

Bison made their own grease in Poland...

JL.................

The Bison package has “FUCHS” on it. That is a grease manufacturer. No idea if Bison picked a stock product they had or it was special formulated for them.

[BCRider]

When the OP says 'plate' presumably he means what is revealed when the chuck is taken off the backplate. Its usually held in place with 3 small screws, take them out, take the 'plate' out, and the pinions and nack of the scroll are revealed.
Just to eliminate something, does the chuck do this jamming when the other set of jaws are used?

Eggzactly.

There seems to be two styles of scroll chucks out there at "our" sizes. The ones with a one piece main body and back cover (first diagram) and ones which split in half at the pinions (second picture). Most I've dealt with are the first style. But if your chuck is the second style I can understand the confusion.

In the first type that back cover also holds the scroll plate forward And if it comes loose the scroll plate can either be forced back against the pinions or if only two screws are loose it can let the scroll cock slightly. And from taking them apart and putting them back together I found that the bore in the scroll plate is typically a VERY close running fit on the running surface of the main body. So much so that it takes some care to ensure the plate goes down quite square. So if your chuck is the first type and the cover is working itself loose it might cause what you're getting.

[Doozer]

The factory recommends that it be greased. I remove the jaws once a year to clean the scroll and teeth. I never let the crud build up.

JL.............

Being smart, I constantly find that I know more "the factory" on many occasions.

-Doozer

[JoeLee]

Eggzactly.

There seems to be two styles of scroll chucks out there at "our" sizes. The ones with a one piece main body and back cover (first diagram) and ones which split in half at the pinions (second picture). Most I've dealt with are the first style. But if your chuck is the second style I can understand the confusion.

In the first type that back cover also holds the scroll plate forward And if it comes loose the scroll plate can either be forced back against the pinions or if only two screws are loose it can let the scroll cock slightly. And from taking them apart and putting them back together I found that the bore in the scroll plate is typically a VERY close running fit on the running surface of the main body. So much so that it takes some care to ensure the plate goes down quite square. So if your chuck is the first type and the cover is working itself loose it might cause what you're getting.

Mine is like the second one pictured. It mounts to an L-00 back plate and nothing is getting past that to find it's way inside. I don't believe there is any plate holding the scroll in there. It's all ground to tight tolerances so when assembled the scroll can't back away from the pinions.

JL................

[JoeLee]

Being smart, I constantly find that I know more "the factory" on many occasions.

-Doozer

Yeah, especially some of the techs I've talked to.

The reason they recommend a certain grease be used is because that is how they rate the amount of tightening force against the clamping force during their tests. If a different grease were to be used those specs would change.

JL..............