Jammed shaft key removal

[Richard Evans 2Participant @richardevans2]

Hi All,

I'm replacing the gears on my mini mill. There is a key on the mainshaft which is totally jammed. Of course there's almost nothing to grip. Pliers just slide off and risk damaging the key. What can I do to get it out??

Thanks!

Richard

[Richard Evans 2Participant @richardevans2]

[Tim StevensParticipant @timstevens64731]

It would help enormously if we had a picture or two. The exact model of mill would also help. Knocking out a feather key can be fairly routine, but if it turns out to be a woodruff, you will only make things worse – for example.

Cheers, Tim

[CirclipParticipant @circlip]

Perhaps explaining the difference between the two would give the O/P a clue? As he doesn't have a photo posting that may be difficult.

Regards Ian

[Richard Evans 2Participant @richardevans2]

Image attached. I don't think it's a Woodruff (the curved ones?). The mill is an Amadeal XJ9512, it is the 'usual' mini mill available under several different brands.

Cheers

Richard

[roy entwistleParticipant @royentwistle24699]

I would use a small chisel on the end and try to lever it up. don't worry about damaging the key it should be replaced anyway

Roy

[Howard LewisParticipant @howardlewis46836]

If the key is a woodruff key ( a semi circle ) one way of moving it is to tap on the extrememe end so that it rotates to bring the other end further out of the keyway.

File or stone off any burrs that you may ahve already produced.

1 This should "unstick" the key. If it moves, with a small flat ended punch may it be possible to rotate it even further, even to remove it completely.

(Before searching to se where it has fallen )

2 There should be more material which can be gripped. If it moves, but does not come out completely.

Don't hammer so hard that the key is "mushroomed", or even worse so that the shaft is bent!

If the worst comes to the worst, you can make a new key!

Turn a piece of bar to the OD of the Woodruff key, part it off slightly too long, for careful filing afterwards ) to the correct thickness, and then cut in half . Not actually, since you want to finish up with one semi circle, cut and file away from the centreline, to produce the Woodruff key that you want.

HTH

Howard

[Tony Pratt 1Participant @tonypratt1]

Mole grips should be able to grip the key, whatever method you use 'gently does it'.

Tony

[Peter SansomParticipant @petersansom44767]

As Roy said, use a chisel to lever it out. You could clean the key with a file. The better way is to get a piece of key steel of the correct width and height, available in both metric and imperial. cut to length and finish with a file to fit. teh keyway.

You can also sometimes find a pre-made, but key steel never goes astray and lengths as relatively cheap.

[Richard Evans 2Participant @richardevans2]

Done! Once I realised how easy it would be to make a replacement if required, I got it with the Mole grips. It was just badly wedged.

Thanks to all. The hardest part was acually posting the photo!

Cheers

Richard

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Richard, I agree with the chisel / Mole gripe idea and personally I would also replace that key with new one. It is usual for keys to be a tight fit in the shaft keyway slot and a very small clearance in the keyway slot in anything that is fitted to the shaft.

Regards Nick.

[Brian WoodParticipant @brianwood45127]

For others in a similar situation, I have found that a sharply ground pair of pincers, gripping the key along its length and then using the pincers to lever the key out works well, for both plain keys and Woodruff.

Regards

Brian

Edited By Brian Wood on 22/08/2021 14:05:25

[Speedy Builder5Participant @speedybuilder5]

Good old fashioned PINCERS – they will grip much better than mole grips (Other brands are available)

Oops – just saw Brian's post.

[Tim StevensParticipant @timstevens64731]

My favourite tool for this job – as long as you can get to the stage shown in the first picture – is an old pair of wire cutters. Grip the proud part of the key so the cutter edges run along the key, and tweak, levering the key out. Cutters with notches from cutting too-hard wire work admirably, and are also useful for removing tight split pins.

Regards, Tim

[Nigel Graham 2Participant @nigelgraham2]

If a Woodruff key these are made to standard sizes and some of "our " suppliers stock them. I think Modelfixings is one though possibly not up to the size you need.

Yes you can make Woodruff keys… but for the effort and electricity used, is it worth it?

[Howard LewisParticipant @howardlewis46836]

Making Woodruff keys?

Depends how urgently you want to be up and running again!

Things usually fail just after the supplier shuts on Saturday, so you are stopped until probably the middle of next week! The same way that the Tap breaks in the last hole!

Howard

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