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atty
01-13-2011, 08:37 PM
Let me start off by saying that this has gotten very personal. I know most of you would have sent this thing sailing across the shop at the nearest round file, but now that I have spent many hours trying to whip its little A$$, I feel compelled to win, one way or the other. Total destruction of the whole thing is not out of the question, although from what I'm seeing, I won't have far to go.

This disaster was brought to me attached to the end of a Milwaukee Hole Hawg and looked as though it may have come out of the engine room of the Titanic. He said that all he was going to use it for was mixing Thinset, so any thoughts of relative precision immediately came off the table.

I managed, after heavy cleaning, to get the chuck off, but it is stuck, and I mean STUCK, in the position shown. We've undergone 24 hours of electrolytic lye bath, 4 doses of OA torch, along with liberal doses of Kroil and PB Blaster. The last dose of OA brought it to cherry red. Yes, I was pi$$ed. Anyway, that seemed to have brought about some movement, i.e. I managed to get the slip ring off.

Now I am stuck. It would seem that the portion of the body where the slip ring crimps over (B) would have to turn opposite of the other section (A) where the jaws are located, which means I have won a battle, but so far losing the war. Nothing is moving.

Aside from launching this thing into the next neighborhood, any ideas? I know it's a lost cause, but like I said, I'm coming away with some kind of trophy for all this effort.

http://i591.photobucket.com/albums/ss352/atty5420/100_3960R.jpg

http://i591.photobucket.com/albums/ss352/atty5420/100_3961R.jpg

Don Young
01-13-2011, 09:08 PM
I think the next step is to use enough force to separate the split nut, where the outer ring has been pressed off. This nut is internally threaded and meshes with threads on the jaws to screw them in and out as you rotate the outer body. It is generally broken into two pieces after being threaded and hardened so the splits fit very closely back together. There should be notches across the nut where the splits are. It looks like one split may be visible in the photo. I suspect the tools of choice might be a hammer and chisel.

Once the nut is off you should be able to drive the jaws out. They go in a particular order like the jaws of a three jaw lathe chuck, in case you want to reinstall them.

Doozer
01-13-2011, 09:08 PM
"B" is actually a nut that is split, or more properly cracked in the middle. Try to tap on it with a hammer to loosen it and once you get an "in", pry it off. Then the jaws are "free" to come out. Work on them next. --Doozer

Walter
01-13-2011, 09:08 PM
Might I suggest the best trophy would be a sales receipt for a new cheap chuck sitting on your bench, a cold beer in your hand, and that thing in the garbage. Trophies are nice when combined with the word "wife". :D Elsewise that thing is gonna draw blood sooner or later...

darryl
01-13-2011, 09:16 PM
I see a bit of a groove in that ring. Maybe try to impact the ring into breaking loose a bit. If the ring is loose but the jaws simply won't move, then move the ring counter-clockwise (seen from the front) as far as it will go, then apply some impact against the jaws. The moment a jaw moves, go to the next jaw. When all three have moved, knock the ring again and repeat. If you manage to move the jaws, then soak the chuck in penetrating oil for the night.

Another idea to ponder- because the parts are relatively small, it would take a sharp and fast impact to 'excite' the jaws or the ring into self-oscillation- something that might help the parts loosen up. You might try buzzing it for awhile with a hammer drill- put a piece of hard rod in the drill to use as the impact tool.

RussZHC
01-13-2011, 09:32 PM
Lost causes a specialty;)

since you asked, try cold rather than heat or very cold and hammer blows

OR

vibrations but not that big...I'm thinking more like ultrasound that jeweler's may use for cleaning

Black_Moons
01-13-2011, 10:14 PM
Id attach my biggest wrench onto it, And crank it till it moves. It will either A: fix it, B: Destory it so you can throw it out and be done with it.
Win win either way, And only takes a few seconds to do.

Carld
01-14-2011, 12:09 AM
http://www.jacobschuck.com/drill-chuck-repair.asp

http://www.beautifuliron.com/jacobs.htm

http://wiki.owwm.com/Default.aspx?Page=JacobsChuckRebuild&AspxAutoDetectCookieSupport=1

The last site looks to be the best but look at all of them.

macona
01-14-2011, 12:58 AM
Lost causes a specialty;)

since you asked, try cold rather than heat or very cold and hammer blows

OR

vibrations but not that big...I'm thinking more like ultrasound that jeweler's may use for cleaning

Nah, ultrasound wont do squat. You need to drive a chisel into that lateral groove to split the nut and get it off. Then you have to try and get the jaws out.

-Jerry

atty
01-14-2011, 01:51 AM
Wow. You guys saved me a ton of further aggravation. I would have sworn that split nut was in fact a solid ring. Of course, as corroded as this thing is, everything looks like one solid mass. I was of the impression that nothing would stand up to electrolysis, OA, and Kroil, but I'm going to have to adjust my thinking. I must admit, those grooves caught my eye, and I had fleeting thoughts of a chisel, but I would have been trying to spin the whole thing rather than looking at it as a two part nut.

Great site, Carld. That explains a lot.

Thanks for the tip, Walter, but I'm afraid that most of my lessons, both machining and otherwise, have come steeped in blood. While there would be some degree of satisfaction seeing it in the garbage, there would be many lessons unlearned. Perhaps the biggest of which might be "Never do this again", but at least I have done it one time.

Great replies. Thanks.

Carld
01-14-2011, 09:45 AM
atty, the only thing I don't agree with about the instructions on the sites is pushing against the ends of the jaws. I prefer to press against the body around the jaws to remove the collar.

Your Jacobs chuck looks like it is not worth rebuilding but photo's are sometimes deceiving. You can use it as a learning experience for when you have to repair a good chuck.

atty
01-14-2011, 11:21 AM
Oh, I think you're correct. The photos are getting worse. Now that I have that collar off, I can see how the red hot treatment carbonized a lot of the gunk, thus allowing me to get this far. However, I may be at the end of the road. The site wasn't specific on how to get the jaws out....whether to drift punch from the back, or press them down from the front. I realize he wasn't dealing with a basket case like this. I think I have some more serious soaking to go yet, and yes, this is quite a learning experience. I appreciate the help.

http://i591.photobucket.com/albums/ss352/atty5420/100_3967.jpg

becksmachine
01-14-2011, 11:29 AM
You have to punch/press the jaws out the back, they won't fit out the nose.

Dave

JCHannum
01-14-2011, 11:33 AM
You have to punch/press the jaws out the back, they won't fit out the nose.

Dave

That won't work. You press them almost all the way back and then push them out individually to the front.

becksmachine
01-14-2011, 11:56 AM
That won't work. You press them almost all the way back and then push them out individually to the front.

Yes, that could be right, it has been too long since I had one apart. :D

bborr01
01-14-2011, 12:06 PM
You are doing the right thing by taking it apart.

If you threw it in the scrap bin and just put a new one on right away, you would learn nothing about the workings of a chuck.

Granted, it may end up in the scrap bin once you are finished tearing it apart.

I have spent a lot of time on things like that. It is called man over machine.

Man 1: Machine 0:

You win.

Brian

atty
01-14-2011, 01:30 PM
Couldn't have done it without you. We now have a working chuck. Granted it's a little loosey, but it came back from the dead, and certainly good enough to hold a mixer for Thinset.

Drive the jaws to the back and then slowly drive each individual one out of the front turned out to be the trick. Lots of wire brushing and grease, and we're back in business.

It was an interesting learning experience. Now I will stop picking up a chuck and wondering what is going on inside as I turn the collar. Thanks to everyone for the great ride.

http://i591.photobucket.com/albums/ss352/atty5420/100_3974.jpg

Carld
01-14-2011, 03:35 PM
Now, when you get a ball bearing chuck and start taking it apart you'll, :eek: , aw geez this is getting interesting. Aww man.

becksmachine
01-14-2011, 04:48 PM
Now, when you get a ball bearing chuck and start taking it apart you'll, :eek: , aw geez this is getting interesting. Aww man.

Geez Carld, don't ruin the movie for him! :D

Dave