Drill chuck run out

[GraemeVW]

I recently bought a replacement used chuck for my pillar drill. It's a Jacobs 34, same as what it had before. Already had the arbour fitted.
I used it today and noticed there was alot of run out.
I bought it as it was smooth and had very little wear on the key teeth.

However, the drill bit doesn't seem to have much run out at all.
I've not measured it yet to check exactly what's going on though.

Before I start messing with it, is it common for the chuck body to run out (I'm going to guess it's getting on for 1mm!), but for the jaws to be true?

Pretty sure the taper in the quill is good as I never noticed any issues with the old chuck and a couple of days ago I used a large mores taper drill with no issues.

 

[zzr1200]

As long as the drill runs true and there's little or no shake in the quill, I wouldn't bother to much...

 

[GraemeVW]

As long as the drill runs true and there's little or no shake in the quill, I wouldn't bother to much...

That's my thought too, just still seemed a little unusual. It may be that this is normally the case but it's not normally as bad as this one.

 

[hotponyshoes]

I have seen that on keyless ones before.
Somebody can't get it undone so has used a big pair of stilsons or something on the chuck.
Left with a chuck that looks like it's wobbling but the drill bit actually runs true.

 

[GraemeVW]

I've been looking at it and there is run out in the bit too.
The Morse taper is running true in the quill but the chuck body isn't.
Seems the arbour is bent.

Put my old chuck back in and it's true.

Seems I'm going to have to either try and straighten the arbour, or swap it with the old one.

I hate trying to get arbours out of chucks!!
I don't have any wedges. Can't remember how I did it last time.

 

[zzr1200]

A press....

 

[GraemeVW]

A press....

Not sure how I'd do it with a press.
Need the wedges that go between the chuck and the lip on the arbour.

I think, last time, I punched it out from the hole in the center of the chuck. Got loads of punches, but can't find the one I used last time
Hole is about 4mm ish.

 

[hotponyshoes]

Open the jaws on the vice just enough to get the about through and hold the chuck with one hand, Arbour with the other and pull the Arbour through the vice jaws sharply and it will drop out.
Poke the about through a bit of cardboard first if you don't want to mark the back of the e chuck.

 

[GraemeVW]

Open the jaws on the vice just enough to get the about through and hold the chuck with one hand, Arbour with the other and pull the Arbour through the vice jaws sharply and it will drop out.
Poke the about through a bit of cardboard first if you don't want to mark the back of the e chuck.

Absolutely no way is that going to work.
Drilled through the inside of the chuck and knocked the arbour out with a punch. Took full force swings with a club hammer, but it came out.
That was the one in my old chuck, I've had that out before about 10 years ago.

I tried the same with the new chuck. After alot of hard club hammer hits, the punch shattered.
By which time, the end of the punch had been mushroomed over and wouldn't come back out.
I had to cut the arbour off, drill through it from the back to be able to get the punch out.
I've continued to dry and drill what's left of the jacobs taper out of the chuck so I can try and folding in on itself but it's not working so far.

I may end up having to give up!

 

[GraemeVW]

Current state of play

Seems the jacobs taper end, if nothing else, is case hardened. Soft in the middle but the outside and end are very hard.

 

[GraemeVW]

Might have another go tomorrow and see if I can grind a slot down the wall and fold it out.

 

[GraemeVW]

Ironically, the one I got out first, I had to put back together so I could drill this second one out!
Will hopefully come apart easy second time round though.

 

[Pete.]

I have a couple of arbors that cause(d) the chuck to run out of true, in fact one was holding a very nice Rohm keyless chck when I got it. I put the arbors between centres and they were clearly bent or warped. Was was a fully-hardened Jacobs original one with no sign of damage it was just bent.

 

[GraemeVW]

I have a couple of arbors that cause(d) the chuck to run out of true, in fact one was holding a very nice Rohm keyless chck when I got it. I put the arbors between centres and they were clearly bent or warped. Was was a fully-hardened Jacobs original one with no sign of damage it was just bent.

There were no marks on the chuck (untill I started smashing things about) so no idea how it got bent!

I guess it happened early on and was taken out if use, hence it still being in good condition (apart from having bits of arbour stuck in it!)

All the marks on the end were caused by me this evening

 

[Pete.]

Beding an arbor can be caused simply by the drill snatching an unrestrained part and the part flying around out of balance. Te forces on the waist of the arbor could be plenty enough to bend it.

 

[GraemeVW]

Beding an arbor can be caused simply by the drill snatching an unrestrained part and the part flying around out of balance. Te forces on the waist of the arbor could be plenty enough to bend it.

Good point, hadn't thought of that.

 

[RichardM]

Can you stick it in a hot oven to heat it up and then drop an ice cube into the middle of the remaining part of the arbor to try and shrink it?

 

[GraemeVW]

Can you stick it in a hot oven to heat it up and then drop an ice cube into the middle of the remaining part of the arbor to try and shrink it?

Certainly something to consider. Not really got a way to get hold of it at the moment, unless I have an easy out that will fit.

I'll continue the battle tomorrow.

 

[slim_boy_fat]

I don't have any wedges. Can't remember how I did it last time.

I was going to offer a loan of my wedges, but it seems I'm too late and you've gone into 'butcher' mode.

 

[GraemeVW]

I was going to offer a loan of my wedges, but it seems I'm too late and you've gone into 'butcher' mode.

Yep!
Thanks anyway, but I don't think they would have got it out anyway!

But, I got the good arbour out of the bad chuck, so as long as I don't butcher the good chuck, it doesn't matter how this arbour comes out.
I'm butchering the arbour so I don't cause more damage to the chuck.

The wedges seem quite hard to get. Loads in America, a couple of very expensive places in the UK, but no easy, reasonable places to get them that I could find.

This is only the 4th time I've tried to do this, but the other 3 did come out eventually. This last one is completely stuck solid!