# Repairs to a Lathe Chuck



## Ranger (Dec 18, 2014)

I recently bought a SB heavy 10 lathe abd with it came a 6" Buck 3 jaw chuck D1-4 mount on it
I disassembled the chuck to assess and clean and lube it and found one of the master jaws has the
last segment/thread broken off, so the unit still works on small diameters but when you get the larger
pieces it has issues. Can a person just buy or order a new set master jaws or are they fitted to the main
body and one set from another won't work properly, this is an older unit say 1980 era with the kind of jaws that
the top unbolts to reverse or be replaced by soft jaws, its the main piece under that that has the broken
part, the scroll itself is fine and only one jaw is damaged but that might be enough to make the unit junk?


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## Karl_T (Dec 18, 2014)

You can try to buy the part as they are still in business, but i wouldn't hold my breath.

If you know a good machinist that works real cheap ( got a mirror handy?), a replacement part can be made.

I did this once, you'll need a rotary table or a CNC. If you decide to go this route, I'll explain what I did.

Karl


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## Smithdoor (Dec 18, 2014)

Try ebay
or just get new chuck from ebay or shars[
If was a lot bigger it may be worth fixing the chuck

Dave

QUOTE=Ranger;256982]I recently bought a SB heavy 10 lathe abd with it came a 6" Buck 3 jaw chuck D1-4 mount on it
I disassembled the chuck to assess and clean and lube it and found one of the master jaws has the
last segment/thread broken off, so the unit still works on small diameters but when you get the larger
pieces it has issues. Can a person just buy or order a new set master jaws or are they fitted to the main
body and one set from another won't work properly, this is an older unit say 1980 era with the kind of jaws that
the top unbolts to reverse or be replaced by soft jaws, its the main piece under that that has the broken
part, the scroll itself is fine and only one jaw is damaged but that might be enough to make the unit junk?[/QUOTE]


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## darkzero (Dec 18, 2014)

My experience (with Bison chucks) are that the master jaws are matched with the top jaws, they're numbered. I've purchased top jaws before & they're supposed to be ground to match the masters (by the owner/user). I never did & they worked fine for that chuck I had but it was a Set-Tru also so I just dialed them in & left it that way. I'd imagine the same would recommended for getting new masters.


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## Mark_f (Dec 18, 2014)

It has been my experience the master jaws are fit to THAT slot in THAT chuck and numbered as such. A friend of mine crashed his Bison 5" chuck and lightly damaged the jaw. The company said they were fit to the body. Each jaw was fit to the properly numbered slot in the chuck body and a replacement would have to be fit, if we could even get one. Fortunately, I filed the damage and repaired his chuck without replacing the jaw. ( a LOT cheaper too).

Mark Frazier


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## 110octane (Dec 19, 2014)

World Wide Chuck Services of Kalamazoo, MI can repair or remanufacture about any chuck.  It will be $expensive$.  You might just want to consider purchasing a new chuck.  WWC will give you and estimate.  They are on the web @ worldwidechuck(dot)com

I have a little five inch three jaw universal chuck that came with my 1953 Logan, WWC helped with a new pinion and a chuck key.  The outside jaws were missing and I found a set on ebay that were close and ground them to fit using my Dremel tool rigged to my vertical mill.  They are a good fit.  You can always true up the jaws using a tiny grinding wheel in the Dremel mounted on center in the compound.  You do loose a little capacity doing this.  You just want to "touch' the jaws with the grinder and not eat into them.  If it requires a lot of removal to true them up, something else is wrong, like the scroll or the jaws themselves, etc.

If the jaw is steel and not iron, (It is probably nitrided low alloy steel) you might be able to TIG weld build up the missing segment and grind it to profile.  That might be a little sketchy, but I've seen some surprising results.

Good Luck, Geoff Morgan


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## jmankin (Dec 19, 2014)

There is a guy on the " forum" by the name of Stonehands.  He has numerous jaws and chucks for SB at very reasonable prices.


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