Mystery tool, collet chuck

[martianParticipant @martian]

When I puchased my milling machine it came was a load of tooling, among it was an incomplete collet chuck.

It looks similar to a clarkson autolock, there is a set of eight collets, 4 imperial & 4 metric.

The collets are different from the clarkson one being unthreaded, slightly longer and of smaller diameter, as per photos.

The collets have sizes stamped on them but other than that there is nothing to help identify.

Can anyone identify them?

[bernard towersParticipant @bernardtowers37738]

Clarkson S type???

[Nigel Graham 2Participant @nigelgraham2]

If anything like mine, Clarkson stamped or engraved their name on the rim of the nut, which you do have there.

The spanner is a proper drop-forged item with embossed name, though what you have may be a local replacement for a lost original.

[martianParticipant @martian]

There is nothing stamped or engraved on the rim of the nut also my drop-forged clarkson spanner does not fit.

As i understand a clarkson S type collet would be threaded

[Dave WoottonParticipant @davewootton]

Long shot and I’m not certain, but years ago I bought a Bridgeport and it came with an Osborne Titanic series 1 collet chuck, which had collets rather like the Clarkson S type but unthreaded, never used it as I already had a Clarkson and Can’t remember the going of it. I’ve used the more common Titanic series 2 at work but never seen the series 1 again, it was a very long time ago but might give you something to google. At some point I’ve seen a set of the instructions, which were pasted in the lid of the box, for the series 1 posted on this site. hope this helps even if it’s just to eliminate a possibility. Don’t think the series 1 was much of a success as never seen another.

[martianParticipant @martian]

Thanks for you input Dave. It doesn’t look like a Titanic 1 if this thread is anything to go by.

https://www.model-engineer.co.uk/forums/topic/osborn-titanic-not-titanic-ii-chuck-conundrum/

[Dave WoottonParticipant @davewootton]

That’s the thing, at least it eliminated something! I do remember that BSA made a collet chuck, never seen one, but was interested as at one time I was mad about (and probably on) their motorbikes.

Good luck with the search, I always find these thing interesting, must get out more.

Dave

[peak4Participant @peak4]

Looks very similar to a Clarkson S type.

Bill

[DiogenesParticipant @diogenes]

The penny might have dropped..

Did this come with your ?Chester mill?

..back in the olden days ‘differing-in-detail-but-all-broadly-similar’  imported copies of self-locking chucks with basic collet sets often came with new machines from the likes of Chester and Warco, either purchased as an extra or supplied as standard..

What taper is it?

I might even have one somewhere, I’ve never even thought of using it..

[martianParticipant @martian]

It did come with my chester mill (3MT), as did a lot of other stuff, some clarkson autolock parts, a posilock chuck with one collet, two vertex ER32 holders with a full set of collets.

I don’t have the part with the taper, only the collets, locking collar and the spanner.

I am just wondering what they are and if I can make use of these odd parts.

[martian]

On martian Said:

…

I don’t have the part with the taper, only the collets, locking collar and the spanner.

I am just wondering what they are and if I can make use of these odd parts.

Not without the missing bits.  These days ER collets are more popular because they grip over a wider range.  They’ve displaced a lot of older collet systems.  Never say never, but I think it will be difficult to find a matching chuck unless some kind person on here has one.  Are they in good condition?

Dave

[old martParticipant @oldmart]

I have used Clarkson Autolock in the size up to 5/8″ and 16mm and currently use an Osborn Titanic II at the museum, but Roger told me that his old firm used another make of collet chuck for threaded shank endmills, Acramil which used two part collets. I have never seen the Acramil tooling but maybe that is what the mystery ones are.

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