# 9x20 jet lathe chuck



## casca92 (Jun 18, 2017)

greetings,
I have a piece that needs a bigger and better chuck than I have currently. backing plate size is 1 1/2 8 tpi
I have a 4" 3 jaw self center chuck
              7" 4 jaw independent chuck ( will work on here if I have to )
Some times my needs and wants get confused with what is affordable until I get off medical and return to work.
not real crazy with the independent tightening chuck.

I think I need a 6 or 8 inch 4 jaw self centering chuck ?  So guide me in the right direction.
would - no have to stay around $ 175 for this purchase.  would like it complete with back plate.

lastly where is a good place to start ? plenty of independent adjusters on EBAY.

thanx in advance
casca92


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## mikey (Jun 18, 2017)

My vote would be a used 5" 3-jaw chuck. Many of them for Atlas lathes on ebay for $100.00 or less. A 4-jaw scroll chuck is harder to find. I think a 6" might be pushing the limit as to size; the jaws may hit the ways if you go too big and an 8" chuck is totally out of the question.


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## Bill Gruby (Jun 18, 2017)

I respectfully disagree here. I use an 8" Cushman 4 jaw on my Jet 9X20 all the time. The lathe has no issues the extra weight and diameter. Had this set-up for about 15 years now.

 "Billy G"


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## mikey (Jun 18, 2017)

Bill Gruby said:


> I respectfully disagree here. I use an 8" Cushman 4 jaw on my Jet 9X20 all the time. The lathe has no issues the extra weight and diameter. Had this set-up for about 15 years now.
> 
> "Billy G"



Good, Bill, glad you jumped in with the voice of experience. I have to ask, though. How large a work piece can you fit in the chuck before the protrusion of the jaws becomes an issue?


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## Bill Gruby (Jun 18, 2017)

I have chucked up 6 1/2 inch dia. but it pushes the limit.  As home hobby people go this is probably all you will ever open to. 8 inch in a 9 inch swing lathe is close. Use caution at all times.
 I have a friend with a HF 9X20 and he has an 8"- 6 jaw in his.

 "Billy G"


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## mikey (Jun 18, 2017)

Bill Gruby said:


> I have chucked up 6 1/2 inch dia. but it pushes the limit.  As home hobby people go this is probably all you will ever open to. 8 inch in a 9 inch swing lathe is close. Use caution at all times.
> I have a friend with a HF 9X20 and he has an 8"- 6 jaw in his.
> 
> "Billy G"



So, you can clamp a 6-1/2" work piece without the jaws hitting the ways? Impressive.


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## Bill Gruby (Jun 18, 2017)

Only with the jaws in the ID three step side  holding position.  The jaws just make it to 1/8 inch past the OD of the body of the chuck. Anything larger is asking for trouble in my opinion.

 I am having (tongue in cheek) a set of jaws modified for the chuck to hold a 7 inch diameter work piece. There will be .375 removed from the OD side of the jaws. They will never be used on that side of the jaws again.

 "Billy G"


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## Bob Korves (Jun 18, 2017)

Get some time on that 4 jaw chuck and get used to using it.  The independent 4 jaw chuck is much more versatile than any scroll chuck, and will give more accuracy.  I almost never use the three jaw scroll chuck on my lathe, not usually worth the time to change over to it, and less accurate.  With a little practice and thought, centering a part on a 4 jaw independent chuck goes quickly.  IMO, it is a required basic lathe skill.  Save your money for real needs...


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## casca92 (Jun 19, 2017)

ok so broke down and used my 4 jaw independent chuck,  a little more time was spent for a project that has taken to long to complete as it was. trying to make a threaded top for QCTP so I don't need wrench. just adding a threaded spacer with a handle.  of course only scrap steel I could locate during my search ( destroy mission ) was a 3 inch diameter Hex in STAINLESS .


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## WoodBee (Jun 20, 2017)

casca92 said:


> greetings,
> I have a piece that needs a bigger and better chuck than I have currently. backing plate size is 1 1/2 8 tpi
> I have a 4" 3 jaw self center chuck
> 7" 4 jaw independent chuck ( will work on here if I have to )
> ...


Any reason you are looking for a selfcentering 4 jaw? I have a self centering 3 jaw and 4 jaw, and a independent 4 jaw.( All came with my lathe)
I almost exclusively use the 3 jaw and independent 4 jaw....
Just trying to figure out if I am missing out on using the self centering 4 jaw.

Peter


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## ch2co (Jun 20, 2017)

When I got my used 10-22 I just knew that that must be big enough for the size of what I planned to do, (telescope parts). As soon as I started
to learn just how to use a lathe I discovered that some of my parts while being under 10" in diameter, wouldn't fit in a chuck and turn a 10" dia.
part, duh. Neither my 3 or 4 jaw chucks would hold an item that was that large. My 4 jaw when fully opened (too far for safety) would seriously
run into the ways and still wouldn't hold a 10 dia. part.  Oh well, just chalk it up to a learning experience. Then it dawned on me to remove the
jaws completely and mount the plate directly to the face of the chuck body. I could bolt it or.....tape it with double sided 3M tape. Hold the part
against the chuck with a live center and there you go. The biggest problem is removing the part from the chuck tape, but a little heat seemed to
do it. Who needs a stinkin' big lathe? (well maybe I do, but...) I've used this method forever 40 similar parts with nary a hitch. I only use my 4 jaw
chuck, independent jaw not scroll, for holding other than round or square, like rectangular parts that are too big for my 3 jaw but not large enough 
to use the tape method.

CHuck the grumpy (but still learning) old guy,


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## casca92 (Jun 22, 2017)

picked up the 6 inch 4 jaw self centering - under my budget   New   from discount machine . Have not opened the box yet 
more will follow.


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## casca92 (Jun 22, 2017)

6 inch chuck mounted  ok,  had to whittle down the face plate a tad.  wished I would have looked a little closer at it. needs to be opened up a whisker to get more threads on and set screw better located.   Jaws will open as far as 3.15 inches from jaw to jaw cross ways.  Any further it will be smackin the rails other wise it was worth the expense to have it on hand.
thanx to all for your input.


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