# Very Stuck Chuck on 17" round head



## lindse34 (Nov 18, 2012)

I had a shaft with eccentric lobes that I needed to polish after making a press on bushing for it. So I thought it would be a great opportunity to try using the 4 jaw to mount the shaft eccentrically so the lobe would be centered. So the first step was to remove the 3 Jaw. After reading about the somewhat weak low speed gears in these machines I figured I'd make a spindle clamp so no back gears were involved. I made it so it would fit on the rear of the spindle without removing the drive pulley and guard. After attaching the clamp and shoving a stand under it to hold it I proceeded to chuck a 1 inch grade 8 bolt  and commenced hanging off the wrench handle. After about 2 minutes of that and adding the obligatory cheater bar (a 2" wrench hooked on the end), the clamp I made started slipping so I grabbed a F clamp to help the 3/4 " bolt that was doing all the clamping before. I could now hang off it but it would still slip a little. This was Friday night so I said enough, sprayed the spindle with penetrating oil and had a beer.






Saturday I got an assistant and after considering our options I grabbed a failed 3" wheel spindle from a farm implement and welded a 2.25" nut on the end of it. I milled 3 flat lands on it for the 3 jaw to grab. We then proceeded to put a 1 inch impact on the 2.25" nut and a 60" pipe wrench on the chucked wheel spindle. We reasoned the combined continuous torque of the pipe wrench and shock of the impact would do the job. After 15 minutes of that we decided heat was needed. Fearing for the spindle seal I was a bit leery of too much heat from the torch but we did it anyway. After 3 cycles heating, impacting and cooling the chuck was still firmly in place. Our limiting factor seemed to be the clamp on the rear of the spindle.





Today I started making a full length clamp for the back side of the spindle so I can get at least 2.4 inches of clamping area. I am thinking I can get 3 3/4" fine thread bolts on it for some ridiculous clamping power. Then I think I am going to remove the 3 jaw from the back plate and make a mating plate on a rotary table. I think we have already put the 3 jaw through too much abuse. I plan to weld very heavy stock of about 12" in length from the center line so we can strike it and a 3 inch square tube that is about 4 feet long for leverage. 

Is there anything else we should be doing to improve our chances? One thing that does concern me is if we use a hammer to hit any lever it will place force on the spindle bearing whereas the air impact does not place a downward force on the bearing. This seems like inviting brinneling of the spindle bearing. I might just weld a 2.25" nut on the mating plate so we can still use the air impact.

If this doesn't work I am just going to cut the backing plate off the spindle and remount the 3 jaw on a new one. I am starting to think this chuck has been on this lathe since the 70's.

And I polished the shaft with the 3 jaw anyway so I don't know why I am still pursuing this..... :nuts:

Thanks and Regards,

Matt


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## 12bolts (Nov 19, 2012)

lindse34 said:


> ...sprayed the spindle with penetrating oil and had a beer.


More oil and more beer. Much much more beer. Got to make sure the oil has time to penetrate :drink2:
Seriously though. What sort of penetrating oil are u using?



lindse34 said:


> Fearing for the spindle seal I was a bit leery of too much heat from the torch but we did it anyway


I am guessing the assistant was the proponent here:thinking: Sorry not much more to suggest than more penetrant and more beer, (oops sorry),,, time for it to work.
Rapid heating is the secret. Big torch. Dont allow too much heat to transfer to the spindle, otherwise expansion here eliminates the advantages gained by heating and expanding the backing plate..............or melting the seals.

Cheers Phil


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## swatson144 (Nov 19, 2012)

I always use a big piece of hex in a 3jaw. Pressure like you are applying and a few shocking raps while it is loaded. The big piece of hex keeps the jaws mostly in their slots and does not slip and ensures the wrench a good grip.

I had to use a wrench and cheater 200 lbs of me hanging off of it and a friend whack the wrench with a hammer. It popped loose on the 2nd whack with no harm. Bouncing up and down on the cheater just makes the clamp slip bit the hammer shock helps and doesn't put much impact on the bearings.

Steve


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## Ray C (Nov 19, 2012)

I feel your pain and had a similar situation after doing a bunch of interrupted cutting.  Every tiny impact on the piece was tightening the chuck.  Anyhow, the solution was relatively easy.  I removed the jaws, put a bar through the slots and put a cheater over the bar.  I rigged-up the tailstock ram to hold a plate against the face of the chuck to keep the pipe in place.  I held a good deal of tension on the bar and a friend whacked the pipe closer to the chuck a few times with a 3lb persuader and bingo.  Gotta be careful of course, when it breaks loose, the guy holding tension takes a spill.  It will come off so hold off on doing anything drastic.  Good luck.

EDIT:  Oh, in your case, you have a 3 jaw so a pipe wont go all the way through the jaw slots but still, I think you can get some mileage out of that technique.


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## swatson144 (Nov 19, 2012)

If all this doesn't get it then the last try before cutting the back plate off would be to warm the chuck all through until the spindle starts to warm from contact and then pack the spindle with dry ice if it's available or even bags of regular ice. The spindle is so little mass compared to the chuck that the only way to get a temperature difference would be heat both and cool the spindle. 

Even heated and cooled expect to have to shock it.

Steve


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## Ray C (Nov 19, 2012)

One other thing... You want to apply torque as far on radius of the chuck as possible instead of clamping a smaller diameter piece in the jaws and trying to spin that (although that works fine for a mildly stubborn situation). Imagine for one minute if you could, clamping a 20" diameter disk in the jaws then, applying the torque from a bar to edge of the 20" disk. There are actually 2 torque forces at play in that case and the total torque is the product of the two.

Anyhow, by putting a bar in the jaw slot, you're effectively creating the torque of the "imaginary" disk mentioned above -but it's a really big disk. If you put an L-shaped piece on the end of the bar you're pusing on and pull on it (instead of pushing down on a straight bar) then, you have the two torques mentioned above working for you. First start with the straight bar and cheater then if necessary, put perpendicual bar on the end of the cheater.

Hope that made sense and that you're not :rofl: at me.

Hang in there, I know exactly how frustrating this is...

EDIT: Don't slap me here but, are you sure that's a spin-on chuck?  -And is that beast unplugged while you're doing all this?


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## ranch23 (Nov 19, 2012)

Ray C said:


> EDIT: Don't slap me here but, are you sure that's a spin-on chuck?  -And is that beast unplugged while you're doing all this?



How goes the battle?


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## lindse34 (Nov 19, 2012)

So today I was leafing through the manual for these lathes that is posted on this site and noticed the 17 inch is supposed to have a L0 long taper key drive. After questioning my memory for about 5 minutes I went to the shop expecting a heaping of humble pie coming my way, but I'm pretty sure its a threaded spindle. I had made this conclusion before based on the 4 jaw that came with it but then I realized maybe it was just thrown in the deal and not actually for this lathe. At any rate I took some pics of the spindle and ironically the threads in one spot were chipped enough to look like a key way but after cleaning it it's just a chipped thread. Which may point to other problems.... Actually I kinda wish it was L0 that would probably be a lot easier. From what I measured I think it is 2-3/4"-8 thread. So I don't know if they sometimes came with that instead of L0. This is the lighter duty version of this lathe so maybe that has something to do with it.






So Ray, for a bit I was thinking your question about spindle type was very relevant. 

Also we unplugged it when we made attempts 1-5 on this thing. I assume your concern is inadvertently turning it on? I was wondering if you had another scenario of concern that didn't involve hitting the switch and bad news ensuing. 

Allegedly the 1 inch impact is rated a bit north of 1600 ft lbs but with the additional mass of the chuck what is actually being felt by the threads would be considerably less. I'm not sure I follow your scenario correctly. 
_"If you put an L-shaped piece on the end of the bar you're pushing on and  pull on it (instead of pushing down on a straight bar) then, you have  the two torques mentioned above working for you. First start with the  straight bar and cheater then if necessary, put perpendicular bar on the  end of the cheater."_
Wouldn't the second perpendicular bar on the end of the cheater bar apply a torque that is then perpendicular to the spindle axis of rotation? Maybe I am not visualizing it correctly. 

Steve,
When I was heating it up Saturday we joked about getting liquid nitrogen to pour in the spindle. It's not terribly hard to get if you know someone that stores livestock semen as people do in the Midwest. Dry ice with maybe some oil to increase the heat conduction seems more practical and we won't have to make a million semen jokes.

Phil,

I was using PB Blaster. I prefer Break Away, but PB was handy. I did see somewhere online someone was touting the merits of Kroil in this situation so I may have to get some. May be good for various other things we deal with that have been welded by time. 

Anyway I bored the center of clamp-to-be tonight and hopefully Mcmaster Carr shows up tomorrow with some 12point 5/8" bolts and grade 8 nuts. It would be a good Thanksgiving present to get this off.




Thanks for all the input,

Matt


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## 12bolts (Nov 20, 2012)

Matt,
Something else I remember reading for a stuck chuck was hanging a very heavy weight on a lever from the chuck and leaving it overnight.

Cheers Phil


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## Ray C (Nov 20, 2012)

Hopefully at noontime or this evening, I'll have time to draw-up a sketch of the L-shaped bar.  Stand by for that.  Also, the concern about unplugging it was purely a matter of safety.  Sorry.  Didn't mean to offend but but if a buddy accidentally hit a power switch with a bar perpendicular in the chuck...  That could be bad...


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## Ray C (Nov 20, 2012)

Here, take a look at this picture. (BTW: You can click the PDF image and use the mouse buttons to see 3D).

You could just use a long bar w/o the L-shape but if space is a limitation, using the L will give you the same torque. Also, you can use the tailstock and a plate to hold the bar into the slot. While somone is putting force on the bar, somebody else should be whacking the bar with a hammer a few inches from the chuck where its inserted into the slot.

Another thought. You can probably make, beg or borrow a chain wrench. The one I have only wraps around 8" bar/pipe stock but they come much bigger. I'd be inclined to make one if I needed bigger.

I know this sounds crazy but, is there any chance it's a left hand thread?  It defies all common sense but, I don't profess to know everthing about every lathe that was ever made...


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## lindse34 (Nov 20, 2012)

OK, now I see why you would do that with limited space. Though it may be hard to apply force perpendicular to the axis of rotation if the second bar is very long. I had the second bar in my mind rotated 90 degrees about the x axis which would make little sense. Fortunately there is room to hang a 20 foot bar off the thing...Now that I think about it there is one out back....

Pretty sure its right hand. I can see some of the threads at the end of the spindle and they are right hand. 

Got the clamp made tonight, hopefully adapter plate on the mill tomorrow night.

-Matt


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## Ray C (Nov 20, 2012)

Well, I sure you you get it off.  Only other minor thoughts I have are to pack the spindle with some ice and heat up the chuck.  And if that long bar bends, a chain pipe wrench wrapped around the chuck would help.  If you make one out of regular chain instead of the bicycle/link chain, you could probably put some rods through the slots that go through the chain links.  You could weld-up a pipe chain in a jiffy.  I suspect you know what I'm talking about but if not, I'll take a picture of my pipe chain wrench and how I'd make one if needed.  

So, have you got someone around to bang on the leverage rod with a hammer?  My guess is that thousands of impacts from interrupted cuts is what caused this mess and when this happened to mine it was the hammer blows (impact) that did the trick.

I'll stay tuned and keep the fingers crossed.

Be careful and good luck.


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## Dbingen (Nov 20, 2012)

I have a Sheldon that had a stuck 3-jaw.  The 4-jaw looked like it hadn't been on in 20-30 years.  I used penetrating oil, heat, impact, etc for over a week, with no success.

I finally chucked a 3/4" by 1-1/2" alum. Bar about 3' long at right angles to lathe axis.  I then used a piece of brass stock that fit closely to the bull gear to wedge it in place.  I set the bar horizontal to the lathe and hung about 125-150 lbs. on the end of it, thinking I'd let it sit over night.  While placing the weight on it, the chuck came loose!  

Now, I never place a chuck on the lathe without carefully cleaning it and putting a little oil on it.  I always bring it tight by hand, too.

...David


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## lindse34 (Nov 21, 2012)

Well it came off). After finishing the spindle clamp I thought I'd try it with the 3 jaw on one more time. With the better spindle clamp we could really hang off the pipe wrench. After the talk of hitting it, I welded a piece of angle iron to the spindle we had chucked so we could use a maul on it. And after about 15-20 strikes it broke loose. To my surprise the threads had oil on them, but I had been dousing it the last 5 days with penetrating oil so maybe that finally did its job.  Good to be done with this. Thanks for all the ideas.


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## swatson144 (Nov 21, 2012)

Congrats and I am glad it came out in the wash.

Steve


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## Ray C (Nov 21, 2012)

Just in time for Thanksgiving as you had hoped!  :thumbsup:


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## Bill C. (Apr 24, 2013)

lindse34 said:


> So today I was leafing through the manual for these lathes that is posted on this site and noticed the 17 inch is supposed to have a L0 long taper key drive. After questioning my memory for about 5 minutes I went to the shop expecting a heaping of humble pie coming my way, but I'm pretty sure its a threaded spindle. I had made this conclusion before based on the 4 jaw that came with it but then I realized maybe it was just thrown in the deal and not actually for this lathe. At any rate I took some pics of the spindle and ironically the threads in one spot were chipped enough to look like a key way but after cleaning it it's just a chipped thread. Which may point to other problems.... Actually I kinda wish it was L0 that would probably be a lot easier. From what I measured I think it is 2-3/4"-8 thread. So I don't know if they sometimes came with that instead of L0. This is the lighter duty version of this lathe so maybe that has something to do with it.
> 
> View attachment 42638
> View attachment 42639
> ...



Matt, one of my uncles told me years ago if you add dry ice and rubbing alcohol that will lower the temperature even more. That is what he used for freeze branding of his beef stock.


I would like to ask a question to all, what can be done in the future to avoid this problem. I have had a few stuck chucks in my career, usually they came loose with a long 2x4 between the jaws but nothing like what I seen on this forum. On the big lathes the chucks were locked on by clamping system, I think a cam lock. It has been to many years to remember for sure.  
  One would think the designers would have thought this problem through.  Bill C.


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## Tony Wells (Apr 24, 2013)

Couple of tips I can remember. Clean all thread and shoulders, make sure everything is the same temperature, and use a little antiseize compound. And don't "snap" it into final position. Push it there with the same basic technique used to remove. Except no impact wrench.


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