Followup on the bad three jaw chuck

I think I'd be leary of buying a used chuck unless I had a chance to test it first. For instance: when I took evening machine shop classes for many semesters, us old guys had to put up with the way the machinery was beat up by the "kids" in the day classes. They didn't take time to clean chucks, let things slip in the jaws, beat on them, etc., etc., etc..

Pete Stanaitis

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Ignoramus18994 wrote:

I cruised enco for the above. Condidering the discount from new, I doubt you are going to get a bargain. Pry that wallet open and get a small chuck for stuff over 5C collet sizes and use the 4 jaw for the rest.

I'm not going to ask you how many items you have turned so far but if if has been seldom, then keep your eye out for a deal and use the 4 jaw. I have a 6" L00 that I have not mounted since the 4 jaw was attached and I yet to feel that the time saved by a centering chuck beat the time and effort to remove the four jaw.

Neither one of us are running production. Keep the 3 jaw in the nice to have column and if you get a deal, gloat. Until then, just use the 4 jaw, and get a collet setup for the small stuff.

Wes

are going to

collet sizes

Maybe I am missing something.

Enco lists a 8 inch three jaw Bison chuck -- with no backplate -- for $854. See their item 272-6002. I bought a 8 inch three jaw Bison chuck with L0 mount, for $50. (first auction).

Enco lists a 10 inch Bison three jaw chuck for $1,095 (item

272-6004). Again, no mount or backplate. I bought a 10 inch chuck with L0 backplate, for $127.

I think that it is not a bad discount from new. You are right and they might have problems. But then they may not have any problems. Most of the stuff that I buy does not have undisclosed problems. The seller is a 100% feedback and he says they are in very good condition. And, why would he have two bad condition chucks?

If all goes well, am going to sell by bad Burnerd chuck with full disclosure of its alignment problems. I might get $10-20 for it.

i

been seldom,

a centering

setup for the

Another 4-jaw guy. I have two 4-jaws, one small and one really big. If I switch at all, it's between those two. And I have 3, 3-jaws that are gathering dust.

-- Ed Huntress

been seldom,

a centering

Forgot to say Wes, I am using the lathe every other day since I got the lathe to work well, but I am running of round stock.

are going to

collet sizes

been seldom,

a centering

column and

setup for the

My lathe has L0 mount, a little harder to make. Did you buy yours from Discount Machine?

i

you are going to

collet sizes

been seldom,

by a centering

have column and

setup for the

The general rule for a 3-jaw chuck is to go about half the maximum swing. Thus for my 12" Clausing, a 6" (or 6-1/4" as the nearest Bison size) is about right.

Was yours a 14" lathe? If so, then the 8" would probably be the better choice. Check to see whether the jaws at maximum extension hit the ways.

4-jaw chucks can come closer. I have a 10" on my 12" Clausing.

Enjoy, DoN.

You would need the LO mount #274-0210 at $121 from Enco, probably get a sale price sooner or later. But the L series stuff seems to be much more expensive than D series.

You might check to see if your bad chuck has a removable back> >> I bought a brand new import special 6" 3 jaw chuck from an e-bay

you are going to

5C collet sizes

has been seldom,

by a centering

have column and

setup for the

RoyJ fired this volley in news:gu2dnY8MLZAoxe_UnZ2dnUVZ snipped-for-privacy@earthlink.com:

nah... my employees will do that for me -- without my asking.

LLoyd

Both of these already have L-0 mounts.

I will try to see what I can do with the bad chuck. It does have a removable backing plate. But if a used "good condition" 8 inch three jaw chuck costs just $50, which is what I just paid on ebay, then it may be uneconomical to do much with it.

i

you are going to

5C collet sizes

has been seldom,

I have not

by a centering

have column and

collet setup for the

are going to

I run a 3-jaw about 99% of the time. Perhaps the issue is what kind of parts are being made. If the part can be made without need for re-chucked second operations and it'll be smaller than rawstock then centering inaccuracy is irrelevant. One can turn a part to tenths precision in a wonky chuck. The part may not be well-centered on the rawstock -- who cares after it's parted off?

It depends on what you make, of course. If you make rivets or screws all day long, a 3-jaw is great.

Just looking at the typical range of hobby work -- certainly my limited hobby work -- the percentage of parts that I would machine in single chuckings from round barstock is pretty small. And I suspect that's true for most people who make model engines, or most of the other hobby metalworking projects.

As Wes says, you can work almost at fast with a 4-jaw on parts you could handle with a 3-jaw. And it's a lot less hassle than swapping chucks all the time. That's why my 3-jaws spend their lives in a drawer, waiting for the economy to collapse and for me to go into competition with the Chinese making sewing thimbles and bronze replacement bushings for antique kitchen appliances.

-- Ed Huntress

[ ... ]

For me, it depends on the size. I'm more likely to use collets if the workpiece will fit.

Well ... as a friend and co-worker used to say (as he chucked up a 4" diameter chunk of aluminum to make a 0.750" part) -- "The best metal is in the middle." :-)

Enjoy, DoN.