removing a sleeve from a blind hole.

[capnahabParticipant @capnahab]

 

This is not easy to describe or photograph. I am not sure how the photos look in your browser but they are anything but the right way up in mine.

I am cleaning up various bits that came with my lathe. I have a drilling attachment. After a lot of penetrating oil and fiddling I have got the sleep out (see photo). It was stuck partly with rust. It is held in by pair of half nuts that are pulled together in the bore and lock the sleeve. They are in a blind hole. At some point someone has left this in the rain and the hole has filled with water and is a sump for an emulsion of water rust and oil. This is what subsequently causes the sleeve to get stuck. I want to remove the sleeve and clean out the sump. The bolt and external nut rotate freely through a sleeve and on the end is the inferior/bottom nut. The top nut seems to be part of the sleeve coming through the blind bored hole in the drilling attachment body.Its this sleeve that I would like to remove.

Edited By capnahab on 06/08/2015 22:54:24

[capnahabParticipant @capnahab]

[capnahabParticipant @capnahab]

Sorry , I was a bit unclear about the sleeves. The main drill sleeve is out. The one I can't get out is the one that locks the drill sleeve into the body of the attachment. Wondered about a gear puller but don't have one.

Edited By capnahab on 06/08/2015 23:48:18

[Ian ParkinParticipant @ianparkin39383]

That locking bolt with the half nuts on should just slide out

remove the nut and put some more washers under it to pull it out or a pair of big screwdrivers under the washer thats there now to slide it out

Or is that not what you are wanting to remove?

[capnahabParticipant @capnahab]

Yes . I want the whole mechanism below the visible nut out. I agree the locking bolt should slide out but won't. Have tried all that.

[Michael GilliganParticipant @michaelgilligan61133]

Capn'

[Assuming that it's the locking device that you are trying to remove … Now confirmed]

.

I agree with Ian; it should just slide out [and, to do its job properly, it all needs to move quite freely].

The outer cotter is usually bored clearance, and the inner one carries the male thread … when the nut is tightened, the whole assembly floats into alignment on the quill.

I would suggest more penetrating oil [personal preference being PlusGas Formula A] …. Whilst you are waiting for that to work; make a little 'slide hammer' to fit in place of the existing nut. … something about 250mm long, with a suitable lump sliding on it should do the trick.

MichaelG.

.

Edit: Here is a nice sketch of something with the right proprtions.

Edited By Michael Gilligan on 07/08/2015 07:48:42

Edited By Michael Gilligan on 07/08/2015 07:55:46

[Brian WoodParticipant @brianwood45127]

Capn'

There is an old fitters trick for extracting sleeves from blind holes.

First make a close fitting shaft for the bore of the sleeve, allow a thou or so of clearance. Pack the hole with grease, push in the newly made shaft and belt the end of it with a big hammer. The sleeve should start to emerge and will 'walk' up the shaft as you continue to drive it out.

Regards

Brian

[Michael GilliganParticipant @michaelgilligan61133]

Brian,

I believe it's the split cotter assembly that he's actually wanting to remove.

MichaelG.

[Brian WoodParticipant @brianwood45127]

Michael,

I was a bit confused about what he does want to shift, he might find the tip useful anyway. I have seen it work as well, it is uncanny to see the sleeve/bush make it's way out

Brian

[Neil WyattModerator @neilwyatt]

Surely just tighten the top nut until the bottom part of the clamp shifts?

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 07/08/2015 09:27:28:

Surely just tighten the top nut until the bottom part of the clamp shifts?

.

Unless there happens to be an anti-rotation device on the distal part.

[jason udallParticipant @jasonudall57142]

Before we get too brutal.

Is there a pin riding in a keyway( to resist rotation )..inserted.from maybe under paint..
..I have seen such that prevents sliding out of lower half…
..
That said might just be crud gluing it in.

[jason udallParticipant @jasonudall57142]

Michael…Great minds think alike..and fools seldom differ

[capnahabParticipant @capnahab]

This is why I come to this forum, – split cotter , that's what it's called !.

Re Neil's suggestion. If I tighten the nut up it pulls the distal half of the cotter up until it hits the proximal part , then the whole assembly reluctantly spins in the hole but will not come out. I think crud is a big issue.

I like the slide hammer suggestion. or may make a couple of oversized washers that I can tighten the nut into that will pull up on the bolt.?.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian Wood on 07/08/2015 09:20:50:

… he might find the tip useful anyway.

.

Quite right, Brian

MichaelG.

[Brian WoodParticipant @brianwood45127]

I don't think there will be an anti-rotation device, the cotters will do that when they grip the shaft, the design is really very simple and in Capn's case it will be some simple burr or similar under the nut that is trapping the whole thing from pulling out.

It's not quite the same thing but these photos show how it is set up on my New Progress drill

[Gray62Participant @gray62]

It's highly likely there is a burr on the top edge of the hole, had this on a few machines. If you remove the nut and washers, can you push the collet parts down the hole far enough to de-burr the top, this may allow the parts to be removed. If you pull the collets out past a burr you will likely gall the parts.

[Neil WyattModerator @neilwyatt]

Posted by capnahab on 07/08/2015 10:06:16:

This is why I come to this forum, – split cotter , that's what it's called !.

Re Neil's suggestion. If I tighten the nut up it pulls the distal half of the cotter up until it hits the proximal part , then the whole assembly reluctantly spins in the hole but will not come out. I think crud is a big issue.

I like the slide hammer suggestion. or may make a couple of oversized washers that I can tighten the nut into that will pull up on the bolt.?.

Or put something – a few M6 nuts, perhaps, between the flat parts of the two parts of the clamp and see it that lest you jack it a bit further.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by capnahab on 07/08/2015 10:06:16:

If I tighten the nut up it pulls the distal half of the cotter up until it hits the proximal part , then the whole assembly reluctantly spins in the hole but will not come out. I think crud is a big issue.

.

O.K. Chaps … this confirms that the capn's cotter does not have any anti-rotation device [at least, not now].

I must, however, mention that they can be quite useful … My Cowells rack feed tailstock unit [which was adapted to a non-Myford tailstock] has the scars to prove it. Yes, the cotter assembly should self-align, but in the real world they sometimes rotate enough to dig-in.

MichaelG.

[ I still recommend the slide-hammer ]

[Neil WyattModerator @neilwyatt]

[OuBallieParticipant @ouballie]

Got those cotters on/in the stub axles on my Austin Seven and been told 'Easy to remove' except I'm having the Devil's own job in doing so.

Geoff – One of those cases of 'Softly softly catchee the monkey'

Edited By OuBallie on 08/08/2015 15:23:45

[capnahabParticipant @capnahab]

Softly softly catch monkey indeed. The main thing needed was patience as usual. Judicious use of the pry bar did it, but it is very tight in there. However I present for you the said split cotter with no anti rotation and associated pool of crud in the depths.

[Brian WoodParticipant @brianwood45127]

Now that you have it exposed, it might pay you to ease the fit a trifle before reinstating it so that both halves of the cotter do their share in gripping the drilling spindle in the future.

I'm willing to bet you will see from the wear pattern that the upper half has a bright shiny patch where it was contantly hard up against the spindle being unable to float slightly as the design intended. Anoither bonus might be marginally easier movement and control of the spindle.

Regards

Brian

[jason udallParticipant @jasonudall57142]

Also maybe add say a file stroke to prevent hydraulic lock?

[jason udallParticipant @jasonudall57142]

Btw..you seem triumphant that there was no anti rotation key.. .
It was just a suggestion that these are sometimes used so check that this isn’t the case.

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