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View Full Version : Stuck 14N Jacobs Chuck disassembly?



mikem
01-02-2014, 06:43 PM
I have a stuck 14N Ball Bearing chuck--the jaws are stuck all the way open. The instructions for disassembly say to close the jaws so they don't get damaged when you press the outer ring off. I can only move the jaws a little bit (they don't even clear the end of the chuck before they jam up.)

What is typically damaged when the jaws are in the wrong position? I don't really have a choice but to force it off, unless you have any better ideas?

Thanks--Mike.

loose nut
01-02-2014, 06:45 PM
Can you see if anything is jammed in one of the jaws that might be wedging the jaws open.

sasquatch
01-02-2014, 06:48 PM
JMO, but there has to be something, a chip or speck of something caught behind one of the jaws.
(Unless this chuck is worn out, and one of the jaws has cocked slightly jamming it?)

mikem
01-02-2014, 06:59 PM
I am wondering if I try to skim a light lathe cut across the opening that the jaws are supposed to protrude from. They look like they might be catching on the edge of the opening?

I slipped a pipe over the chuck key and even with lots of force it won't open.

What will I break if I press the outer ring off the chuck to free the jaws?

lost_cause
01-02-2014, 07:18 PM
it sounds like yours is jammed pretty good, but i'm assuming you did lubricate the living daylights out of it first, didn't you? i've bought a few jacobs super chucks that have been incredibly dry and had chips and filings jamming them up. in all of mine, a very liberal spraying of wd-40 from every angle, followed by a few minutes to soak in, and all it took was a strong jiggle of the handle to get it moving afterwards.

Stepside
01-02-2014, 07:26 PM
I just "repaired" a Jacob's chuck. Someone had drilled through a part and rubbed the end of the chuck on the part. a few strokes with a diamond stone and I could close the chuck. While involved I took it completly apart after a real good soaking with Kroil. A little extra polishing in the jaw grooves where they exit the chuck and it runs like new.

Pete

rickyb
01-02-2014, 07:39 PM
I have a stuck 14N Ball Bearing chuck--the jaws are stuck all the way open. The instructions for disassembly say to close the jaws so they don't get damaged when you press the outer ring off. I can only move the jaws a little bit (they don't even clear the end of the chuck before they jam up.)

What is typically damaged when the jaws are in the wrong position? I don't really have a choice but to force it off, unless you have any better ideas?

Thanks--Mike.

The last one or two teeth on the back side of the jaws may interfere with the ring and be broken on disassembly. I have done it on a smaller Jacobs chuck. After trying the above suggestions, go for it. New jaws are not expensive on eBay. The teeth clear about half way open, which is where I set them before disassembly. It is more stable that way while pressing the ring off.

mikem
01-02-2014, 07:41 PM
I did oil it well, but to no avail!

The nose of it seems really soft and looks like maybe someone beat on it and mushroomed the end onto the path of the jaws?

Stepside
01-02-2014, 09:14 PM
If the "nose" is soft, take a clean and sharp single cut file and dress it until all edvidence of the "beating" is removed. Then debur the inside edges with a stone or a fine chainsaw file. The "beating" was probably done while trying to mount it to a taper. Sometimes the bigger hammer treatment does more harm than good.

I like to put the taper in the freezer for a bit and heat the chuck until it is almost too hot to hold. If both the internal and external taper are clean and burr free, there is nothing more than a tap with a dead blow hammer to seat the chuck.

Mike Burdick
01-02-2014, 09:47 PM
From an internet search it appears these are the parts that come with a repair kit. So.... these are the parts that one can basically destroy in the attempt to free up the chuck.

http://www.use-enco.com/ProductImages/0859515-21.jpg


http://www.use-enco.com/1/1/68181-30345d-jacobs-ball-bearing-super-chuck-replacement-parts-drill-chuck-parts.html

mikem
01-03-2014, 01:02 AM
I got the jaws to protrude slightly by cleaning up the peening on the nose but the chuck is still jams after a few turns. Tomorrow maybe I'll try to press it apart. Buying the parts kit for $140 is more than what is sensible for me to spend since I have other chucks. It is just a shame that this one screwed up!

mikem
01-03-2014, 01:13 AM
Parts are $45 on eBay if I ruin it!

GEP
01-03-2014, 08:05 AM
The jaws have to be at mid range open to press the chuck appart. Example chuck range 1/8-1/2 the jaws have to be set at 5/16 open or you will damage the chuck. Just soak it in 50% automatic transmission fluid and 50% aceton and hopefully you will be able to move the jaws

mikem
01-03-2014, 08:27 AM
I will try the soaking......what have I to lose? It is so crazy that it turns freely for a few revolutions and then solidly jams. There May be an imbedded chip in the gear teeth?

I tried a tube slipped over the chuck key for more leverage and could feel the handle of the key flex from the force. More force than that will probably break or permanently deflect something.

Stepside
01-03-2014, 09:16 AM
Open it all the way and work on the inside of the nose. Maybe even file off a bit more from the face of the nose. It only takes a "frogs hair" to cause them to stick. Soak it with Kroil or ATF and let it sit for a day or two.

lynnl
01-03-2014, 11:10 AM
If you have some sort of mechanical vibratory device to shake it for a few hours you might be able to shake loose whatever is binding. Nothing to lose by trying. ...put it in that zone where it turns freely to do so.

Maybe take it to a paint store and ask them to shake it.

mattthemuppet
01-03-2014, 11:41 AM
I freed up a couple by soaking them in WD40 for a few days (zip loc sandwich bags), then pressed them apart with some plastic plumbing pipe that happened to be about the right size. the 5/8 one needs doing again though as it's not spinning as smoothly as the 1/2 one

Mike Burdick
01-03-2014, 12:03 PM
mikem,

Did you contact Jacobs and discuss the problem with them? I would think they could give you ideas as to the probable cause of why it won't close or if it's possible to take it apart if the jaws are in the position you have now. A Jacobs ball bearing super chuck is well worth the effort to save!

As for my opinion: I have a Jacobs 18N super chuck and it got a chip in it and wouldn't open. I kept running mineral spirits thru it until the chip moved enough for me to get it working again. When I opened it, I found the chip.

Jacobs phone number: 1-800-688-8949

http://www.jacobschuck.com/contactus.asp

.

PT Doc
01-03-2014, 09:38 PM
I would contact Jacobs as well. You don't have an issue that they haven't seen dozens of times. Be patient and you won't good the thing up.

mikem
01-03-2014, 09:59 PM
I called them today and was on hold for 10 minutes. I'll try them again next week.

cc2
01-05-2014, 12:01 AM
I'm guessing that you might have some cracked or broken threads on the two piece threaded nut, or maybe some bad threads on one or more jaws. If you can get the jaws open as much as you can. You should be able to press the sleave off and see what is happening inside. You probably will need a rebuild kit. If your chuck has a rebuild kit number on the chuck nose you will need the expensive rebuild kit. If there is no number on the nose you will need the older kit which is cheaper. I just went through this last month on a 16n. I called Jacobs to see if I could use the cheaper kit and they told me the parts are not interchangable.

The rebuild is easy. Parts are expensive. I was lucky and found a set on ebay for a reasonable price, otherwise I was thinking of just getting a used older chuck for about the same price as a rebuild kit.

One way or another I think you are going to have to take the chuck apart to see what is wrong.

Good luck

mikem
01-05-2014, 11:20 AM
Another chuck like the stuck one is gritty and I thought I would take it apart to clean it up for practice on the other one. I tried to press the chuck apart on my Greenerd number two Arbor press. I couldn't exert enough force on it to get it apart. How much pressure does it take to press one of these apart?

The Greenard is about 18" tall and I don't have it bolted down, but I thought it could exert the force needed to open the chuck.

The jacobs website shows the press pushing on the jaws, with a pipe the right diameter one the back. Am I supposed to push on the jaws?

dp
01-05-2014, 11:49 AM
The jaws should be about half closed and yes, you press on them. The spacer for supporting the shell on the press has little room to fit and should not press on the body of the chuck or you will break something. I use my machinist's vise as it is adjustable.

cc2
01-05-2014, 06:22 PM
Another chuck like the stuck one is gritty and I thought I would take it apart to clean it up for practice on the other one. I tried to press the chuck apart on my Greenerd number two Arbor press. I couldn't exert enough force on it to get it apart. How much pressure does it take to press one of these apart?

The Greenard is about 18" tall and I don't have it bolted down, but I thought it could exert the force needed to open the chuck.

The jacobs website shows the press pushing on the jaws, with a pipe the right diameter one the back. Am I supposed to push on the jaws?

I used a vise and it came apart pretty easy.

TOOLZNTHINGS
01-05-2014, 07:48 PM
The jaws are marked for position in the body. Sometimes by the spacing of the teeth on the ends. Best to mark yourself to be sure.
I believe you can find instructions for all this by searching on the net.

Brian

cc2
01-05-2014, 08:04 PM
The jaws are marked for position in the body. Sometimes by the spacing of the teeth on the ends. Best to mark yourself to be sure.
I believe you can find instructions for all this by searching on the net.

Brian

Good point That I forgot to mention.
Here is a link:
http://www.jacobschuck.com/drill-chuck-repair.asp

mikem
01-05-2014, 09:49 PM
I used my big Wilton bullet vise and got it apart. One of the half nuts is chipped and the pieces were jamming things up. The broken half nut will have to be replaced, but it is one of the newer ones that have the ball bearings in a plastic cage. Looks like I will have to watch for a repair kit to pop up on eBay at a good price. Thanks for all your help!

I had another one that was gritty and it just needed cleaning. I got it apart and together without incident. Works well now.

mikem
01-05-2014, 09:50 PM
I used my big Wilton bullet vise and got it apart. One of the half nuts is chipped and the pieces were jamming things up. The broken half nut will have to be replaced, but it is one of the newer ones that have the ball bearings in a plastic cage. Looks like I will have to watch for a repair kit to pop up on eBay at a good price. Thanks for all your help!

I had another one that was gritty and it just needed cleaning. I got it apart and together without incident. Works well now.

cc2
01-05-2014, 09:55 PM
Good to hear you got it apart.
My nut was broken also. It took a couple of months of watching on ebay. I bought parts for my 16n for $43.00, which was a good deal, because I have one of the newer ones also which cost alot more than the older ones. It works like new now.
Good luck

TOOLZNTHINGS
01-06-2014, 08:44 PM
The nut is two pieces and it just looks like it is broke.

flutedchamber
01-06-2014, 09:45 PM
Try to find an old stock repair kit with the loose bearings. Many more bearings in the old kit makes for a longer lasting chuck rebuild.

mikem
01-06-2014, 10:58 PM
I don't think that the old stock repair kits fit the newer chucks with the cages surrounding the bearing balls.

One of The half nut threads are broken where they should not be!

JoeLee
01-06-2014, 11:04 PM
Not if you crunched a tooth. The teeth on those jaws are very brittle.

JL................
The jaws have to be at mid range open to press the chuck appart. Example chuck range 1/8-1/2 the jaws have to be set at 5/16 open or you will damage the chuck. Just soak it in 50% automatic transmission fluid and 50% aceton and hopefully you will be able to move the jaws

mikem
01-06-2014, 11:26 PM
The jaws threads or teeth were fine ----it was the threads on one of the half nuts that were chipped and that's the reason I couldn't get the chuck apart. some of those chips were stuck in the threads in there and jamming in the threads. Maybe the previous owner had a crash while drilling.

I soaked it for days and banged it on the wood work bench from several angles numerous times, trying to dislodge the chips inside.

I did take apart a couple others that were gritty and cleaned and lubed them. They work well and I learned a lot about drill chucks!

I would have opened the chuck jaws farther before I pressed it open if I could have moved them!

flutedchamber
01-07-2014, 12:49 AM
I don't think that the old stock repair kits fit the newer chucks with the cages surrounding the bearing balls.

One of The half nut threads are broken where they should not be!

If you replace the half nuts with the old style, you can use the loose ball bearings.

IIRC, not only are the half nuts a different thickness for the "new and improved" captured bearing type kits, but they don't have the bearing loading ports ground in the sides. The older kits are less money and have more bearings. Look on Ebay, I've found great deals there.

mikem
01-07-2014, 08:39 AM
have you tried using the old stock kit on a newer bearing before?

I like the old kits and the larger bearings....and the lower price!

JoeLee
01-07-2014, 11:19 AM
I figured if it was jammed something crunched inside, weather it was the teeth on the jaws or the half nuts. Had it happen before. Those parts are really brittle and when your pressing the collar you don't have a feel for what is happening inside.

JL..................
The jaws threads or teeth were fine ----it was the threads on one of the half nuts that were chipped and that's the reason I couldn't get the chuck apart. some of those chips were stuck in the threads in there and jamming in the threads. Maybe the previous owner had a crash while drilling.

I soaked it for days and banged it on the wood work bench from several angles numerous times, trying to dislodge the chips inside.

I did take apart a couple others that were gritty and cleaned and lubed them. They work well and I learned a lot about drill chucks!

I would have opened the chuck jaws farther before I pressed it open if I could have moved them!

flutedchamber
01-07-2014, 12:09 PM
have you tried using the old stock kit on a newer bearing before?

I like the old kits and the larger bearings....and the lower price!

As long as you replace the bearing races and balls as a unit, you can retrofit the old stock kit on a newer chuck.