Chuck Dismantle

[Alan Worland 1Participant @alanworland1]

I have an old (probably very old!) 3 jaw 4 in chuck which I am trying to dismantle for cleaning.

After removing the backplate it can be seen that the rear centre section will come out but appears to be prevented by the scroll operating gears, and I cant see how they come out!

The manufacturer is – The DE Witch Machine Co of New London, Conneticut USA (needless to say I cannot find them) and is unusual in that the chuck key requires a female square to fit

Other chucks I have retain the gears by a pin or screw.

 

Alan

[Alan Worland 1Participant @alanworland1]

[David Southwell ARPSParticipant @davidsouthwellarps]

Posted by Alan Worland on 18/08/2011 17:10:11:

I have an old (probably very old!) 3 jaw 4 in chuck which I am trying to dismantle for cleaning.

After removing the backplate it can be seen that the rear centre section will come out but appears to be prevented by the scroll operating gears, and I cant see how they come out!

The manufacturer is – The DE Witch Machine Co of New London, Conneticut USA (needless to say I cannot find them) and is unusual in that the chuck key requires a female square to fit

Other chucks I have retain the gears by a pin or screw.

 

Alan

DAVID: Hi Alan I have dismantled quite a few chucks recently but am not familar with this one. Any chance you could post some photos?

I often found dismantling was helped by judicious use of an appropriately sized piece of hardwood and a mallet! But I would hate to suggest you did that without having some idea of its internal construction. Does the scroll operate successfully or is there a problem with them?

[David Southwell ARPSParticipant @davidsouthwellarps]

A further thought. If you look down inside the centre of the chuck can you see where the two main components of the chuck meet?

 

I usually find a nice piece of hardwood will rest on that joint. This is when I apply the mallet moving around about 100 degrees between thwacks whilst one part of the chuck is held firmly the other part usually starts to move.. Usually not too much force is needed to separate the sections.

[Alan Worland 1Participant @alanworland1]

Thanks for your reply, when the schroll is tapped it moves the centre section (with a join line around the bolt holes) – oily line in second photo

However it will only move about 25 thou before it stops against the gears (they go tight)

and I cant see any method of retaining them! third photo

I believe I somehow need to pull the rear section out to gain access to the gears and their retaining method

 

Alan

[Alan Worland 1Participant @alanworland1]

Whoops! Thats what happens when you take photos in the half light!

The name is ‘DE Whiton’, (not Whitch) who appear to be well heard of in the chuck world!

Having another look it seems I might have to make a puller to extract the rear section.

 

Alan

[David Southwell ARPSParticipant @davidsouthwellarps]

The hardwood + mallett worked for me.

 

I think these chucks have pinions similar to early Pratt Barnard (1940 ish) .. held in place by from the centre unlike later PB which are held in place by a pin. I found it difficult to use a puller. The mallet/hardwood trick is unlikely to do any harm as long as you keep moving around the centre. I think I can see the join line in the cventre in photo 2. A good prior soaking in a light machine oil helps but clean the oil and any debris off inside the centre before using the hardwood otherwise you will get very little purchase. Alternatively use a brass tip on the end of a punch.

 

David

 

 PS I think your gear may have gone tight due to corrosion around the part of the pinion at the inner end. If so you should be able to clean it away – do not force any movement of the jaws – that could damage the pinion.

Edited By David Southwell ARPS on 18/08/2011 22:44:28

Edited By David Southwell ARPS on 18/08/2011 22:47:33

Edited By David Southwell ARPS on 18/08/2011 22:53:20

[Richard ParsonsParticipant @richardparsons61721]

Hi Alan.

If you look at the back of the chuck you will see in the screw holes a discontinuity. This indicates that the centre of the chuck back is separate and splits on a line at about 1/3 of the screw’s diameter. The screw threads actually hold the whole thing together. The front view confirms this. You will see a fine band showing where the inner part joins the outer from the back.

When assembled the whole thing would have been machined. The ‘DE Whiton’ company did not mean it to come apart.

If you have a small woodruff cutter, cut two shallow grooves just on or below the joint as seen in the photograph. Use a brass punch and drive the back out. If that does not work. If SWMBO is agreeable (or is out) stick it in the oven at about 120° C for an hour and try the brass drift again.

Good luck. If you have to be really rude to it well at the moment it will not work so you cannot make it much worse.

Dick

[Ex contributorParticipant @mgnbuk]

The ‘DE Whiton’ company did not mean it to come apart.

I rather doubt that – depending on what it is used for, cleaning of any chuck can be a regular occurence. I would not expect to have to dispose of a chuck just because it wanted cleaning !

I would try the following –

 

Place a stout piece of reasonably flat timber on a solid surface.

Firmly “rap” the chuck (rear face down) squarely onto the timber.

 

I would expect the inner section to move until the clearance from the rebate was taken up – this may provide a split line accessible though the centre that a drift will fit in. If not, set a couple of pieces of wood to effectively increase the depth of the rear rebate & “rap” again until the centre section drops clear.

 

This method has worked for me in the past with 3 jaw chucks.

 

In a previous employment, this was the method employed to remove the interference fit front bearing from large lathe spindles (large as in 16″- 24″ + bore bearings). These fitted up to a shoulder & few manufacturers provided holes for drifts to remove the bearings. A long bar was bolted across the front of the spindle nose, the spindle stood on the opposite end on an old sleeper – loosely suspended from the crane in case it slipped or toppled – and was “bumped” by 2 people on the bar onto the sleeper. The bearing would (slowly !) work it’s way off with no damage to the spindle. The replacement bearing would be heated to expand it & just slipped into place.

 

1st post here after lurking for a while !

 

Regards,

 

Nigel B.

[David Southwell ARPSParticipant @davidsouthwellarps]

Posted by Richard Parsons on 19/08/2011 11:02:10:

Hi Alan.

If you look at the back of the chuck you will see in the screw holes a discontinuity. This indicates that the centre of the chuck back is separate and splits on a line at about 1/3 of the screw’s diameter. The screw threads actually hold the whole thing together. The front view confirms this. You will see a fine band showing where the inner part joins the outer from the back.

Agreed.. There may be another way to do this.

 

Make three bolts with a matching thread. Use a gauge determine the depth of the hole and the distance to the discontinuity.

 

Turn the end of the new bolts down to a length about 5mm longer than the distance between the discontinuity and the depth. Turn the end of the bolts down enough to clear the thread. Harden the end and then slowly tighten the bolts. Tighten each one a little at a time. The pressure should be enough to release the bond.

[Alan Worland 1Participant @alanworland1]

Thankyou for all your advice! As I said if the scroll was tapped back into the body it would push the rear centre out but would then stop because of the pinions and yes the join line goes through the bolt holes (photo must be better than I thought!)

Today I had a surge of inspiration! I found an old suspension rubber bush which was a very tight fit in the chuck bore, I then found some thick close fitting washers and with a length of 10mm studding compressed the bush in the bore – really tight

I could then tap out the rear of the chuck, voila!

It was a really tight fit but very well machined with the pinions coming out from inside

Dont think it has seen much use but will have to make a key for it so once its cleaned and oiled I can check its accuracy

Thankyou all!

 

Alan

[David Southwell ARPSParticipant @davidsouthwellarps]

Posted by Alan Worland on 19/08/2011 20:47:41:

I could then tap out the rear of the chuck, voila!

…

Thankyou all!

 

Alan

DAVID: Great: Any chance you could post a photo of the pinions and the components so there is a permanent record showing how the chuck is constructed? Some dimensional info would be particulalrly helpful along with identification of the model and serial number.

 

Edited By David Southwell ARPS on 20/08/2011 10:50:57

[Richard ParsonsParticipant @richardparsons61721]

Nigel Thanks I forgot that trick. It rather like bopping a carden shaft to draw the cup out of Hardy-Spicer joints. The cup comes out on the side where you hit.

[Author]

Posts