4 Jaw Independent Lathe Chuck

[JT.]

i am in the market to buy a 6" one
to do hobby machining (+some gunsmithing)
is it ok to buy a cheap one ore are there advantages buying an expensive chuck
(i am not thinking on buying one that is independend and self centering combined )
are soft jaws a must ?

[h=1][/h]

 

[7HC]

i am in the market to buy a 6" one
to do hobby machining (+some gunsmithing)
is it ok to buy a cheap one ore are there advantages buying an expensive chuck
(i am not thinking on buying one that is independend and self centering combined )
are soft jaws a must ?

I don't know, but my thinking when I recently bought a 5" independent 4 jaw for my little 7x12, was that at least I'll always be able to center things as accurately as my dial gauge will allow, even if the quality of the chuck isn't that great.

I'm not sure what you regard as cheap or expensive, but mine cost $109 with a mounting adaptor plate from the LMS.

M

 

[JT.]

I don't know, but my thinking when I recently bought a 5" independent 4 jaw for my little 7x12, was that at least I'll always be able to center things as accurately as my dial gauge will allow, even if the quality of the chuck isn't that great.

I'm not sure what you regard as cheap or expensive, but mine cost $109 with a mounting adaptor plate from the L150MS.

M

150 dollar is ok

 

[Sandro]

The usefulness of a 4 jaw chuck comes from the independent adjustment of the 4 jaws. Its quality has less to do with its usefulness and more with how you use it. I've used very badly worn 4 jaw chucks and still managed to accurately center work. Soft jaws are not necessary with a 4 jaw chuck since accurately centering work is always possible, soft jaws are only useful with 3 jaw self centering chucks. If you buy a used chuck the one possible problem might be worn jaws. The tips of the jaws wear more rapidly than the base of the jaw, the end nearest the body of the chuck. The reason is that most of the time shorter pieces of material are held in the chuck near the tips of the jaws. The jaws can be trued up with a tool post grinder, but even a Dremel will do the job if you are patient.

Hope that helps answer your question.

Sandro Di Filippo

 

[Bill Gruby]

If you have never used a 4 jaw before you will probably find it somewhat of a challenge at first. You will get the part almost zeroed and a tweak will suffice and than wham, you went past your intended zero and have to come back. This is not to discourage you as we have all been there, it is to help you in your decision. Frank is spot on the T-slot version is best by far and the easiest to maintain. You will develop in time the feel of the sdjustment and zero comes extremely fast.

For my mones the 4 jaw is best. I very seldome go back to the 3 jaw unless one of my kids already has it on the spindle. URGH.

"Billy G" )

 

[JT.]

I agree that the usefullness of a 4 Jaw chuck is greater than a 3 jaw. There is almost nothing a 3 Jaw can do that a 4 Jaw can't and if you have the type with "T" slots cut in to the face makes the 4 Jaw even better. If you can only afford 1 chuck the 4 Jaw. However some beat chucks will have the Jaws sprung and they will never hold anything right!
If down the road a 3 Jaw happens to become available plain back or not fit your spindle you can chuck it in the 4 Jaw. If available get the 2 piece jaws. Being able to bolt on soft jaws is a plus!

Frank

do you mean thise style ?



ore go for thise style
http://www.hbm-machines.com/comasy/templates/product.aspx?contentid=237&productid=4069

 

[Bill Gruby]

I can't speak for Frank, but yes that is the one I was speaking of.

"Billy G" )

 

[george wilson]

I use Bison chucks most often. They are accurate,and not as expensive as some are(though lately they have gotten MUCH more expensive). I cannot evaluate all inexpensive Chinese chucks,but I can offer possible flaws in cheap 4 jaw independent chucks: It is possible that their jaws' slots might not be perfectly parallel,so the jaws could be at an angle to the centerline of the turning. Faces might not be square to the centerline(CL). It is possible the bodies may be made of crappy grades of cast iron,too soft to resist the jaws from pressing into the iron with repeated use. I did have a cheap 4 jaw that came with a Romanian lathe,whose jaw screws actually would FALL OUT when I took the jaws loose to rotate then,and that chuck wasn't even Asian!!

It's possible that the threads on the back won't be square to the body,and the chuck could wobble some thousandths so you could never make accurate work with the chuck.

I could go on,but you get the idea. I'd try to buy a 6" Bison if you can. At least test the runout of the face,and parallelism of bars clamped in the jaws. Look VERY carefully where the jaws meet the metal clamped in them to see if you can see ANY light under either end of the jaws. Cheap metallurgy,you can't really see or do much about.