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View Full Version : crap, what next ? chuck issues



davidh
08-18-2010, 09:24 PM
i have a 6-1/4" good bison chuck i got about 5 years ago. . . its quite accurate according to what i have read on this forum.

well, its been getting harder and harder to turn the wrench so i fugured it was time to disassemble, clean the swarf out and get it back in or4der. . .

wrong. after cleaning carefully and wiping with oil per directions, the jaws only go back in about 1/2 way before they start binding. . . just as the did when i took it apart. its not dirt or swarf but probably due to getting a few parts to get jammed at one time or the other.

now what ? ? ? ? i cannot see where its binding but because all three jaws kinda stick at the same place its gotta be the body, right ?

i could use it as it is and fight with the key every time i use it but would prefer to have it work as it was suppose to. . . . .

recondition maybe ? i think ive seen it offered somewhere but have not looked, i thought i would get a little input first. . . .

stillworking on the honda carbs. found sticky things and some dirt in one of the bowls. . . more on that later on a different post. . . .

davidh
(way too many things to do, waaaay too few saturdays left)

squirrel
08-18-2010, 09:59 PM
Can you post a pic of the chuck, some of those can be split pretty easy so the scroll can be removed for cleaning. If yours is that hard split the case and clean it that way. You will break the pinon teeth if you crank on it really hard. Take it apart and look at the scroll and see if it is rubbing on the body. They can twist if they are dropped but more than likely it is just some crap inside.

Toolguy
08-18-2010, 10:09 PM
There is probably more dirt and chips you just haven't gotten out yet. Once it is very clean it will run easily again.

RobbieKnobbie
08-18-2010, 10:20 PM
if you don't find any more dirt or chips in there (and I bet you will!) maybe you can give it a good once over for dents or dings in the threads. A small deformity in a thread - scroll or otherwise - can cause big headaches.

wierdscience
08-18-2010, 10:30 PM
Slip the jaws out,degrease everything and color in all the mating surafces of the jaws and slides with Marks-o-lot.

Put the jaws back in and crank home,crank them back out and see where the Marks-o-lot rubbed off.

That should show you where the distortion if any is at.

RichardG
08-18-2010, 11:25 PM
This is a lathe chuck? if so I have one that did The same thing took it apart and cleaned it out acted the same ,after looking at every thing found that the pins that hold drive pinnion / gear had worn the pin on both sides of the one that is number one made new one works like a charm . That one was the number one that is allwise used to tighten the chuck.
Richard

TGTool
08-19-2010, 12:04 AM
Davidh

I'm not clear when you say you disassembled it, whether that was just removing the jaws or disassembly to the point of removing the scroll. If you haven't split the chuck that would be the obvious next thing to do. It can sometimes happen that chips can work their way around to the outer or inner edges of the scroll and bind it up.

Ken_Shea
08-19-2010, 12:24 AM
Presuming as TGTool inquired, it was completely disassembled, you can try replacing one jaw at a time to see which one/s is/are binding, then looking carefully at that jaw and guide for burrs/dings or galling.

I use way lube for lubricant, some use none, some use plain oil.

winchman
08-19-2010, 05:40 AM
Richard G: "That one was the number one that is allwise used to tighten the chuck."

Huh?? Why? The numbers on a 3-jaw are only there to designate which jaw goes in which slot. You can tighten the chuck with any one of the screws. I always use the most convenient one. I sometimes use all three for work that I want really tight, but I still start with the most convenient one.

Blackadder
08-19-2010, 08:02 AM
my 3 jaw has a designated key hole for best accuracy it is marked near the square hole with a zero

the jaws are as you would expect 1 2 3




Stuart

davidh
08-19-2010, 09:37 AM
and cleaned with wash tank, blown dry with air and lightly lubed. . . its still disassembled and i tried each jaw into the body before putting anything else back together. . . . (it is still totally apart on the work bench)

each jaw is tight at about the same distance from the outside diameter of the body. . .

just for heck of it,i tried reversing the jaws in their respective slots, still tight in the same place. i even tried putting the wrong jaws in the wrong slots and came up with the same problem.

i CAN get it assembled using a small brass drift and small hammer and it will be the same as it was when i took it apart except for the swarf that i removed.

any more ideas ? ? ?

wierdscience
08-19-2010, 09:51 AM
Sounds like the chuck body is deformed,did you ever roll a part out of the chuck?

You might put it all back together and check the chuck for bellmouth.

Toolguy
08-19-2010, 09:59 AM
You might try lapping in each jaw in it's respective slot till they all move easily.

S_J_H
08-19-2010, 10:03 AM
Absolutely split the chuck and clean it 100%. If it still wants to lockup at some point a little high spot blue might help to locate the problem.

davidh
08-19-2010, 10:21 AM
Sounds like the chuck body is deformed,did you ever roll a part out of the chuck?

You might put it all back together and check the chuck for bellmouth.

yes i have. . . and i'm thinking thats about what did it. im going tocheck it closer today, maybe it can be polished a little with 600 grit wet or dry. . .

more to follow . . . .