Burnerd Multi-Size Lever operated Collet Chuck

[Martin-Sy]

That should sit in a recess in the adjusting cap

Yes, it was in there. I'd just taken it out to see if that was the issue.

Here are the major components:

There are nine 15mm dia ball bearings in the main body pockets which press against the rear taper of the sliding cone.
When the lever handle is moved to the close position the balls are forced inwards which in turn move the sliding cone outwards forcing the collet to close.

The sliding cone with evidence of where the balls act on it.

Maximum movement of the sliding cone is about .075" (just under 2mm)
ATM I'm not sure what the two keyways are for.

The release key looks distorted and may not be original.

On close inspection it looks like two parts silver soldered together.

Is the grub screw original? Could it have been replaced with an over-long one?

I do not know. It's certainly possible that it's been replaced at some point.

I think the bronze part would have to move in integer multiples of the nose thread pitch.

Yes, I think you're probably right.
I say probably because I cannot tell whether the threads evident in the locking pad were cut when the part was made or have just worn into it over time.

Anyhow it seems like @Smouser has full kit of parts for these chucks.
I'll drop him a pm

 

[Martin-Sy]

The penny has dropped!
Firstly there are two different styles of nose ring.

One has serrations on the outside but no grub screw. The other is plain with a small knurled section and grub screw. See items 4.
The operating instructions differ. The grub screw variant instructions say loosen before and tighten after adjusting the nose.
So the grub screw and pad (well the parts diagram does call it a locking pad!) must be intended as a locking device.
The serrated nose version instructions say:

This version must have a click detent although it's not apparent on the exploded diagram.

 

[Smouser]

Oh wow.

My key was just a 'normal' key/feather key.

Looked something like this.

No fancy release keys.

HOWEVER, as I have said before, the key I had in there looked wrong and I had ball bearings missing. So maybe my chuck won't work as it is anyway

I failed to get the Huvema lathe into the garage today. Had a delay with a dodgy coolant pump. 15 minute job turned it to a bit of a nightmare.

Hoping to finish the coolant tasks off tomrrow and then get the lathe into the garage.

Once that main task is done, I will get a chance to look at my chuck again and take photos.

 

[Agroshield]

Firstly there are two different styles of nose ring.

Once you have set the brass locking piece, it would give repeatable location of the nose piece every time you removed and reinstalled it. As the cone pushes the collet against this, it gives length-repeatability using a length stop in a turret.

Have a look at the Colchester Lathes Company YT video (1:04), where they make the bell. That is the same chuck you have, and the fifth station in the turret (after the clapper-installation tool) is the length stop.

With the serrated cap, you'd need to count the number of clicks to make sure it was exactly the same measurement from the spindle nose face, a practical impossiblity.

Perhaps one cap is for production/repetition work and the other (serrated) for more day-to-day stuff.