Anyone know how to disassemble this chuck?

[SteveM]

Any idea on how to take this chuck apart?

It was stuck and I managed to get it to work by flushing it with solvent to get any grease and grime out, and that worked well, but it really needs a cleaning.

I just disassembled and cleaned a 4-jaw scroll chuck and that was easy, as I was able to tap it apart with a small hammer, but even a small hammer on this might damage it.

The center in the back looks like it could be pressed out, but I figured I check before I started doing anything.

Steve

[Inspector]

Any chance it unscrews from the back?

Pete

[whateg0]

What happens when you take the screws out of the jaws?

[SteveM]

What happens when you take the screws out of the jaws?

It just exposes the master jaws.

Steve

[SteveM]

What happens when you take the screws out of the jaws?

I don't see anything that tells me that.

Here's an additional pic describing how the parts move relative to each other.

When you unscroll it all the way, the jaws just stop when they hit the outer ring.

They don't come out like on most scroll chucks.

Steve

[Harold_V]

There's a threaded collar on the back side that is unscrewed, which then allows the main body to separate.
See the line around the three holes you see on the back? That's the treaded collar. You can just make out a pin hole around its perimeter, likely used to tighten or loosen the collar, or it's a set screw to prevent movement of the collar once properly tightened.

Amazing---a miniature chuck with soft jaw capabilities. A real gem for those who understand soft jaw use.

H

[SteveM]

There's a threaded collar on the back side that is unscrewed, which then allows the main body to separate.
See the line around the three holes you see on the back? That's the treaded collar. You can just make out a pin hole around its perimeter, likely used to tighten or loosen the collar, or it's a set screw to prevent movement of the collar once properly tightened.

You are probably seeing a reflection off a ding in the metal, as there is no hole in the collar.

It's possible that if I make an arm with three holes and screw it to the back that I can get it to unscrew.

Steve

[Harold_V]

The three holes are a part of the front of the chuck, so attempting to turn it won't unscrew the collar. The collar must be turned while the center piece remains stationary.

Take a very close look at the line around the three holes to determine if there's a thread. It would be relatively fine in pitch, so it may not be real obvious. If you find there is no thread, then my thoughts are likely misguided.

One thing is sure--the chuck exterior is made of two pieces. Some means keeps them together. The collar makes sense, and may be pressed on, to a stop to assure the required clearance. How it is applied may not be by threads. That was just a guess, bolstered by what looked like a hole in the periphery.

H

Edit:
As the mounting is a part of the chuck body, the retainer on the rear does not see a load, so it could very well be pressed on.

[SteveM]

As the mounting is a part of the chuck body, the retainer on the rear does not see a load, so it could very well be pressed on.

I think that may be the key.

The inner part with the three holes is the same piece as the face of the chuck.

The ring around it may be holding it with a press fit.

As the backplate or mounting arbor would be attached to the center, there would be no load on it that would work the press fit loose, particularly if the backplate pressed up against both pieces.

I'll have to look for a ring or piece of pipe I can use to support the knurled ring and put it on the press.

Steve

[SteveM]

Press fit is the answer:

You can see the dirt in the scroll. While the dirt is pretty small, so is the scroll, so it really tightened it up.

Steve

[Bill Shields]

when all else fails....push harder....

[SteveM]

when all else fails....push harder....

Mac's law of repairing Volkswagens: "Use a bigger hammer".

Steve