Buck Ajust-Tru disassembly?

Soak in more economical diesel for a month?

SW

I was gonna say toss it in a buck of used detergent motor oil left over from your last oil change.

--Have you considered calling Buck?

There's two plate to remove. The "adjust" plate should have about six socket head screws bolted on the back side of the chuck. Next, the scroll plate shoould have about six longer socket head screws going through the face of the chuck.

If things are normal, the scroll itself should just fall out. I've not worked with a frozen one but you can tap on the scroll with the jaws removed. You may have a bit of challenge here, but at least no more fasteners are holding you.

I've not removed the chuck keys on my cleanups and I don't remember how they come out.

karl

Hmm. I was going to say that, but thought, "What do I know?" ;-)

Heck, I didn't even know one of those could _be_ disassembled! =:-O

Cheers! Rich

Thank you gentlemen. Soaking in penetrating oil and calling Buck are both good plans, but patience is in short supply in Jersey. The instructions on the Buck website are for a different, no doubt newer model. It was pretty straightforward, as Karl suggests. I tapped a single edge razor blade followed by a knife blade into the seam between the sections, then tapped the jaws and interior pieces out with a copper drift. The upshot is a usable, if chewed up, 5" three jaw harvested from a vendor's $5 table. If anyone asks, I'm dedicated to conserving the earth's resources. Not just cheap.

Kevin Gallimore

Ok, good job. What was it that froze it up? What kind of back plate? My brother gave me a damaged dividing head that has a Buck chuck that is screw-on like a small lathe would have.

Paul

brother gave me a damaged dividing head that has a Buck chuck that is screw-on like a small lathe would have.

The adhesion appeared to be caused by 50 years worth of dried coolant and a light touch of rust. It has no backplate. If I had had a high confidence level on the chuck repair, I would have tried to get one at the show.

Kevin Gallimore

Never had a genuine Buck -- but the basic principle would be:

0) Before doing *any* of this, prior to removing anything, check for marks so the parts can be reassembled in the same relative position as they were before. If there are no marks, make some. say two center punch marks on either side of the dividing line between the chuck body and the adjuster collar, and three on either side of the dividing line between the adjuster collar and the backplate. 1) Remove long screws through body to backplace. 2) Remove backplate. 3) This should expose counterbored screws in the collar which carries the offset screws. Remove those screws to remove the collar from the body of the chuck. 4) At this point, you should be able to get to the screws which attach a reduced diameter cover plate from behind the scroll plate. Remove these, and the backing plate. 5) Remove the scroll plate. (The bevel gears on the wrench sockets may be on either side of the scroll plate, so you may have to remove them before you remove the scroll plate. 6) Once the scroll plate is out, the only thing holding the jaws in place should be friction. Depending on how badly abused the chuck was, you may have to drive them radially out -- using some aluminum or hardwood to transfer the hammer blows to the jaw bodies close to the surface of the chuck body. (Lubricate the ways first, of course.

Good Luck, DoN.

564

brother gave me a damaged dividing head that has a Buck chuck that is screw-on like a small lathe would have.

That means that you will have to make a backplate with the projection against which the offset screws work.

Enjoy, DoN.

Well, in English, "disassembled" - to dissemble is to ramble, pontificate, etc.

But I nitpick.

However, it's true, I do know this - for a three-jaw chuck, the three jaws have to be 120 degrees "out of phase," as it were.

Now, _that's_ dissembling. ;-D

Cheers! Rich

LOL

Better clean it out really good before use...

Or take an existing backplate and bolt a suitable projection onto it.

Also, whenever I remounted these I generally would clock over to the next set of thru-holes--this provides you with a nice new divot surface for the setscrews to bear against.

Pretty much all my chucks have soft jaws these days and so there's really no need for a buck here anymore--esp since they'll make your lathe vibrate like crazy if you don't keep them reasonably balanced.

--FWIW many moons ago I got a 6-jaw Buck for my Myford; there were no suitable back plates to match so I made a pattern and had a few cast up on the theory I'd mess a few up getting one right. First one came out perfect so I've got a drawer full of castings. Tell me the measurements you need and maybe I've got iron to fit..

Oops! You're right. I'll have to check my points. The fingers on the keyboard are mis-firing.

Thank you. The center boss needs to accommodate an 1 1/2" thread for a SB. The chuck is a 5", and the mounting holes available are on 4 1/2" centers. The thickness is flexible because the "Ajust-Tru" centering block can be built up using a separate piece.

Kevin Gallimore

brother gave me a damaged dividing head that has a Buck chuck that is screw-on like a small lathe would have.

You can buy castings made specifically for these chucks.

Jon

Note that the jaws *may* be numbered in the bottom of the grooves the ways run in, and the slot may have a number which only becomes visible when the jaw is fully removed. The jaw numbers are likely to be a serial number and an individual jaw number. If the numbers in the jaws don't match, you have a franken-chuck. :-)

Also -- while it is apart -- check for play between the scroll plate and the center of the chuck body. If you find some, measure the total gap with feeler gauges and cut a strip of shim stock one-half the thickness that the feeler gauge shows and wrap it around the center before you slip the scroll plate on (if you can control it that way) or if necessary, slip the scroll plate on and then work the shim stock in between it and the center of the chuck body. The more play you have here, the more the jaws will shift off center when tightened, and the more they will move if you use a different socket to tighten them.

There should be a socket which is marked (with a stamped '0' or something similar) which gives the minimum runout when used. You may have to grind the ends of the jaws to bring this back to true once you have the shim stock in place.

Best of luck, DoN.