Cleaning scroll chuck

[BazyleParticipant @bazyle]

dissassembly

[BazyleParticipant @bazyle]

My 'new' lathe came with self-centering 4 jaw of unknown make and vintage but "No 8" stamped on the front.. Taking it apart for cleaning I find instead of a scroll retaining plate held on with screws it seems to be pressed on. I can't see a thread for ti to be screwed on and it appear to have been fitted, assembled, drilled for the tail end of the gears, then split and the gears fitted. The flats needed for clearance for the gears look like a spanner potential and scuffing looks like someone tried that once but I can't see any trace of screw thread.

So how does this come apart?

BTW the 'obvious' ring is not the joint just a ledge in the central column and the actual join is 1/8 further out.

Edited By Bazyle on 29/03/2015 17:54:27

[Ian PParticipant @ianp]

I have only had one or two chucks apart so I may be way off here.

I doubt very much that the central ring (with the two flats) is screwed on. It is more likely just pressed on.

The ring would not have any tendency to rotate and its held by the gears presumably as well as being clamped by the back of the chuck.

With the jaws removed you have three access places to push the scroll backwards.

Ian P

[Oompa LumpaParticipant @oompalumpa34302]

Posted by Ian Phillips on 29/03/2015 20:57:54:

With the jaws removed you have three access places to push the scroll backwards.

Ian P

Or, as this is a four jaw chuck, four places to push from.

graham.

[Ian PParticipant @ianp]

Posted by Oompa Lumpa on 29/03/2015 21:02:00:

Posted by Ian Phillips on 29/03/2015 20:57:54:

With the jaws removed you have three access places to push the scroll backwards.

Ian P

Or, as this is a four jaw chuck, four places to push from.

graham.

True, I should have economised and used two less words and just said 'you have access…'

I have learned something else as well. I had always assumed that 4 jaw scroll chucks would have four holes for the chuck key.

Ian P

[BazyleParticipant @bazyle]

HMmmm, yes, I was hopig someone would have experience before I tried the brute force approach. I will have to look into a design change to make service easier. I guess it has never been cleaned fully though a 4 jaw scroll probably never got used much.

[HopperParticipant @hopper]

Before using any brute force, try heating the ring with a propane torch to expand it and loosen it's fit on the centre column. Stuffing a cold wet rag down the hole in the middle might help a bit too.

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