slipping chuck

[brickyParticipant @bricky]

I have a problem with my drill chuck comeing adrift from it's taper,having hammered it back on a few times I could do with some ideas how to prevent this as it's getting tiresome.

Frank

[brickyParticipant @bricky]

[Martin ConnellyParticipant @martinconnelly55370]

If it is a drill with a morse taper socket then the arbor between the drill and the chuck can be replaced quite cheaply. It may solve your problem.

Martin C

[Mike PooleParticipant @mikepoole82104]

It could be worth doing a blue check to establish the tapers are not damaged and match each other. They should not need hammering as the taper is designed to self hold and should not need much more than a good tap to mate firmly. A job that causes vibration or side loads can loosen a taper. Is this a machine with a chuck taper as the spindle nose or a chuck mounted on an arbor to fit a morse taper spindle? Is the taper that comes loose the one in the body of the chuck or the arbor to spindle taper?

Mike

[SillyOldDufferModerator @sillyoldduffer]

I'd start with a good clean and then inspect the state of the male and female tapers.

A taper spinning can do enough damage to spoil the grip until both tapers are corrected, but hopefully it's just dirt, old oil, or bits of swarf. They can reduce the grip badly too – you can guess how I know.

Reamers can be bought to fix the female tapers, but I think it's cheaper to just replace spoilt males. It's what my ex-wife decided to do about me…

Dave

[Clive FosterParticipant @clivefoster55965]

Regrettably hammering a drill chuck onto its taper will almost certainly wreck the tapers.

Right way to do the job is to sit the chuck on the taper adapter wit the tang side down and bang the tang end down hard on a solid, non deforming, surface a couple or three times. The jolt and vibration should set the taper so tight that its immobile without wedges or an extractor. If it doesn't one or both tapers is bad enough that, short of welding, the thing will never hold.

Are you sure the tapers actually match.

Some of the metric B series are so close to the JT series that its nigh on impossible to tell the difference without careful measurement. Except they won't hold. B16 I believe is the example I ran into long enough ago to have forgotten the details.

If the chuck is an inexpensive one, most likely of a certain vintage, it may not have a correct to spec taper in the body. The aforementioned B16(?) issue was with a chuck that could not be re-attached to the arbor it came with. Investigation showed the chuck body taper to be pretty much midway between the B series and the closest Jacobs. The arbor was to spec and had clearly been pressed on with very heavy force. I ended up re-cutting the taper in the chuck body to correct specification and cleaning up the scrapes on the arbor. Chuck body was quite soft.

Clive

[brickyParticipant @bricky]

The drill is a startrite Mk2 and I have owned this, drill bought from a factory,Frank for 30+ years and never had a problem until now.I don't know what the quill taper is but the chuck is original.I don't take a a ball pein hammer to it but a dead blow hammer to just tap it back up.

Frank

[Mike PooleParticipant @mikepoole82104]

Do you remember if you were doing anything unusual or a non drilling activity the first time it came loose? The tapers may have collected some damage when it first came loose and no longer locks like it should, a very close examination and cleaning and then check with engineers blue to see if they still have a good match.

Mike

[Clive FosterParticipant @clivefoster55965]

As Mike says the is something seriously amiss an a very careful examination will be needed.

Normally those directly mounted on the quill chucks become pretty much immobile after a few years and need very serious efforts to shift. I think its safe to assume that the spindle taper and cuck taper were ebyond reporach when made.

Clive

[HopperParticipant @hopper]

Posted by bricky on 17/05/2022 21:05:37:

The drill is a startrite Mk2 and I have owned this, drill bought from a factory,Frank for 30+ years and never had a problem until now.I don't know what the quill taper is but the chuck is original.I don't take a a ball pein hammer to it but a dead blow hammer to just tap it back up.

Frank

So, is it the Morse taper going up into the quill that is coming loose? Or is it the short taper that holds the chuck on to the end of the arbor that is coming loose?

The latter can be fixed with Loctite. The former is probably some burring on either the male or female taper that needs removed.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by bricky on 17/05/2022 21:05:37:

The drill is a startrite Mk2 […]

I don't know what the quill taper is but the chuck is original.

.

**LINK**

http://www.lathes.co.uk/startrite-drills/

It appears that the standard fitment was a Jacobs chuck, directly mounted onto the quill’s male J33 taper

MichaelG.

.

http://www.hhrobertsmachinery.com/Support/Tech_Notes/Jacobs_tapers.html

Edited By Michael Gilligan on 18/05/2022 08:42:38

[HopperParticipant @hopper]

Posted by Michael Gilligan on 18/05/2022 08:25:25:

Posted by bricky on 17/05/2022 21:05:37:

The drill is a startrite Mk2 […]

I don't know what the quill taper is but the chuck is original.

.

**LINK**

http://www.lathes.co.uk/startrite-drills/

It appears that the standard fitment was a Jacobs chuck, directly mounted onto the quill’s male J33 taper

MichaelG.

.

**LINK**

Edited By Michael Gilligan on 18/05/2022 08:42:38

Aha! Thank you. That makes much more sense now.

In which case, Loctite is probably the most expedient solution. (No pun intended ) I won't specify the grade. One of their high-strength retaining compounds. But not the high-temp one if you ever want to get it off by using heat.

[egaParticipant @ega]

Assuming that the quill's taper is not hardened, it should be easy enough to drill and tap for a securing screw; the requisite clearance hole in the base of the chuck could also be tapped for a jacking screw to facilitate eventual removal.

[Dave HalfordParticipant @davehalford22513]

Posted by bricky on 17/05/2022 21:05:37:

The drill is a startrite Mk2 and I have owned this, drill bought from a factory,Frank for 30+ years and never had a problem until now.I don't know what the quill taper is but the chuck is original.I don't take a a ball pein hammer to it but a dead blow hammer to just tap it back up.

Frank

In which case the problem may be sloppy bearings or the chuck has begun holding a drill off centre due to wear. A short taper like a J33 can't take any horizontal wobble at all.

[not done it yetParticipant @notdoneityet]

A tiny differential, but if the parts are serviceable – and only if – a more permanent fitting of arbor to chuck could be achieved by shrink fitting.

I very quickly learned that cool and warm parts can cuse difficulty when removing arbors from my mills – so I am always careful to make sure the ‘fresh’ arbor is as warm as the quill, when changing tools.

[Dave HalfordParticipant @davehalford22513]

Posted by not done it yet on 18/05/2022 10:51:12:

A tiny differential, but if the parts are serviceable – and only if – a more permanent fitting of arbor to chuck could be achieved by shrink fitting.

I very quickly learned that cool and warm parts can cuse difficulty when removing arbors from my mills – so I am always careful to make sure the ‘fresh’ arbor is as warm as the quill, when changing tools.

But in this case it's spindle direct to chuck so that may give dismantling problems later.

[Clive Brown 1Participant @clivebrown1]

The Jacobs chuck on my Fobco did show a tendency to detach if, say, too high a speed made a largish drill chatter. A dab of Loctite stopped that. Now been OK for several decades.

Edited By Clive Brown 1 on 18/05/2022 14:50:10

[brickyParticipant @bricky]

Thanks to all for the input,I will check everything as suggested and possibly use locktite.

Frank

[Howard LewisParticipant @howardlewis46836]

Faced with this problem, I would feel inclined to lap the two tapers together, and then follow up with dab of anaerobic, rotating the two against each other to ensure that it is evenly distributed.

Howard

[not done it yetParticipant @notdoneityet]

Posted by Howard Lewis on 19/05/2022 12:11:27:

Faced with this problem, I would feel inclined to lap the two tapers together, and then follow up with dab of anaerobic, rotating the two against each other to ensure that it is evenly distributed.

Howard

Hi Howard,

If they are properly lapped together there will not be any space for the sealant, if the parts are assembled correctly.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Dave Halford on 18/05/2022 10:33:22:

Posted by bricky on 17/05/2022 21:05:37:

The drill is a startrite Mk2 and I have owned this, drill bought from a factory,Frank for 30+ years and never had a problem until now.I don't know what the quill taper is but the chuck is original.I don't take a a ball pein hammer to it but a dead blow hammer to just tap it back up.

Frank

In which case the problem may be sloppy bearings or the chuck has begun holding a drill off centre due to wear. A short taper like a J33 can't take any horizontal wobble at all.

+1 Vibration is one of the few things that will open a tight drill taper in good condition. Normally, drilling makes the taper tighter, but mine's come off a few times drilling through metal sheet and I've missed the sacrificial block of wood underneath. Since a scary incident I always clamp the job so it can't take off or spin, but without support, the drill chatters violently and then gets a sharp downwards jerk as the flutes entangle with the part-cut hole. Otherwise the chuck has to be wedged off with a hammer!

I suppose vibration caused by worn bearings, a damaged belt, or a bent pulley would loosen the taper too. As Dave says, drill tapers can't take sideways wobble at all.

Dave

[Michael GilliganParticipant @michaelgilligan61133]

Posted by not done it yet on 19/05/2022 15:02:53:

Posted by Howard Lewis on 19/05/2022 12:11:27:

Faced with this problem, I would feel inclined to lap the two tapers together, and then follow up with dab of anaerobic, rotating the two against each other to ensure that it is evenly distributed.

Howard

Hi Howard,

If they are properly lapped together there will not be any space for the sealant, if the parts are assembled correctly.

.

Sorry to disappoint you, but anything rougher than a ‘black-polish’ should have plenty of surface texture for the usual anaerobic retainers to do their job.

MichaelG.

.

Recomended reading: https://5.imimg.com/data5/AE/AX/JM/SELLER-2044578/loctite-retaining-compound-638.pdf

Edited By Michael Gilligan on 19/05/2022 17:09:53

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