How to lubricate a clockmakers chuck

[BigAlParticipant @bigal15229]

I have just acquired a Wolf Jahn clockmaker’s lathe. It came with three chucks, two of which have six jaws. Both of them were seized solid. I have disassembled the first, cleaned and polished the components ready for reassembly but do not know if it should be lubricated, and if so, what with. It is 75 mm diameter and the face, moving jaws and the carriers are steel. The scroll is brass. Can anyone offer any advice please?

BigAl

[BigAlParticipant @bigal15229]

[BigAlParticipant @bigal15229]

Sorry, a typo in my first post. The correct chuck diameter is 68mm.

[Clive HartlandParticipant @clivehartland94829]

Personally I would use graphite paste, Are the jaws screwed on? If so that might explain why they are seized. I understand that you set up the work and can then tighten up the screws.

Clive

[BigAlParticipant @bigal15229]

Yes, the jaws are screwed on. There are three chucks, a three jaw, already fitted to the spindle, the other two in a box of accessories. The chuck I have in pieces is one of two that was in the box. Both it and its partner in the box, another 6 jaw are seized. They have been horribly treated, as have most of the WW collets that were also in the box. This one, at least, was jammed as each jaw was fitted to a totally different part of the scroll. As one was at the outermost section and another at the innermost it was easy to see what the problem might be. I confess to being very relieved to see, when I got it apart, that there was nothing else wrong apart from some burring in the ways which a small file sorted out.

I have some graphite grease which I am happy with on a bigger chuck. I am trying to be cautious here so please forgive my questioning you, but do you not think that it might be a bit thick for something of this size. As you might guess this is my first foray into clock making equipment.

BigAl

[Clive HartlandParticipant @clivehartland94829]

The graphite paste will stick to the scroll and should not, 'Fling off'' when its rotating. as the scroll is only moved slowly it will have no effect on thickness of the paste/grease. While its in pieces you could make sure you get the jaws in the right slots and I suggest using a piece of round metal and put the jaws in the slots and move them around until you get register. I hope that makes sense to you. Hopefully they are numbered but you can number them when you get it sorted.

[BigAlParticipant @bigal15229]

Every part is not only numbered with its position in the chuck but all parts have a 'unit' number so I know that all the accessories are part of the same set. Funnily enough though, although all the jaws and their internal clamping pieces are numbered the outer face of the chuck only has the 'unit' number and makers name so no indication of which jaw goes in which slot.

Actually the slots and clamping pieces are my current problem as they have been terribly bruised. All I can do, and am slowly doing, is remove the bruising by carefully grinding. And I do mean carefully; something like 0.0001 inches at a time. Yes, 1 tenth of a thou at a time. Then reassemble the jaw and retry. Thank you for your replies Clive. When I reassemble the chuck for the final time I will use graphited grease as you suggested.

BigAl

[Clive HartlandParticipant @clivehartland94829]

BigAl, I have just had a look at the type of Graphite paste I use for Chuck assembly:- Molykote G-Rapid Plus and is available in 50 grm tubes. It is sold as an assembly paste for gears and pistons and rings etc.

Clive

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