# What lathe operations need something like this?



## wquiles (Jul 26, 2008)

LATHE CHUCK - KITAGAWA 12" HYDRAULIC CHUCK & CYLINDER
http://dallas.craigslist.org/dal/tls/770591255.html


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## gadget_lover (Jul 26, 2008)

That's a good question. 

I imagine that it would be used in an automated production line, possibly with a bar feeder.

On second thought, wouldn't a productoin line use a collet instead?

Good question WIll. Does it fit your lathe? 

Daniel


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## wquiles (Jul 26, 2008)

gadget_lover said:


> Good question WIll. Does it fit your lathe?
> Daniel



Naaahhhh - the 6" chuck I have is already a little bit too big/heavy for my 8x14 lathe :devil:

I am just really curious why would anyone need something like this and how it is used - it looks like a serious piece of equipment, and if the seller is right, very expensive as well 

Will


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## Anglepoise (Jul 26, 2008)

I am going to guess that it is something to do with machining oil drilling pipes.

I won't guess about the quality of Kitagawa chucks. My 3 jaw is still very accurate after many years of use.


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## McGizmo (Jul 26, 2008)

I have no direct experience with CNC equipment but it would not surprise me that most don't have a chuck as opposed to collets. I believe some of the machines can actually part the work piece from the bar and continue work on it holding it either in the primary chuck or a live tail chuck. I don't even have a clue as to what these parts would be called. If the machine used collets, it would have to change them during the operation. A chuck can quickly accommodate a part that changes in diameter where it is to be held.

I know we have some CNC fluent guys here who can put this to rest.


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## dom (Jul 26, 2008)

Used on a CNC lathe - the 3 slotted parts on the chuck have serrations where T nuts and hard or soft jaws are bolted on.

You set the jaws in the serrations to suit size of material used as the in-out movement is limited to maybe 5mm.

The soft jaws are usually used for only one particular regular job and not used for any
other. You bolt the jaws on, then machine them to required diameter with them in their closed position. Put them back on in the same positions when needed again and they will be true within microns.

We have MANY sets of soft jaws 

The hydraulic unit moves the serrated slides in-out and i 'think' is also for hydraulic spinning of the chuck.

The back plate should be able to come off the hydraulic unit so you can put longer bar thru.


Cheers
Dom


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## RPM (Jul 26, 2008)

CNC Lathes use hydraulic units for actuating the jaws when using a chuck (Kitagawa is nearly a standard) and also ....when used in conjunction with a collet nose piece... i.e. 3J or 5C it provides the movement to collapse the collet. They are adjustable for pressure which allows you to crank the pressure when you need it and lighten it when the part is more delicate. The spindle motor provides the rotation. A typical looking 2 axis lathe...


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## wquiles (Jul 26, 2008)

Cool - thank you guys. I learned something new today 


Will


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## Rothrandir (Jul 27, 2008)

Collets are really only used on dedicated bar feeder machines. Most production cnc lathes will use 3-jaw chucks with softjaws. On the first operation of a part you may be running barstock, but if you have to do a second operation on the backside you're going to want to cut jaws to fit the part.

Here is an example of some softjaws cut to hold a ~6" part in a 6" chuck. This is in a Mazak QT 100:


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## Rothrandir (Jul 27, 2008)

Here is a picture of the softjaws cut to hold the tapered shank of a CAT40 tool, which might give you a better idea of how the softjaws are cut to shape to hold a part that would otherwise be impossible to hold:


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## Mirage_Man (Jul 27, 2008)

Rothrandir said:


> Here is a picture of the softjaws cut to hold the tapered shank of a CAT40 tool, which might give you a better idea of how the softjaws are cut to shape to hold a part that would otherwise be impossible to hold:



Now that's pretty darn slick!


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## PEU (Jul 27, 2008)

Rothrandir said:


> Here is a picture of the softjaws cut to hold the tapered shank of a CAT40 tool, which might give you a better idea of how the softjaws are cut to shape to hold a part that would otherwise be impossible to hold:



Hey Keypuncher :nana: one question: do you use the toolsetter in the machine? I mean that collapsable arm near the chuck. 

I asked in the CNC shop I use to go for parts and they said that over time the toolsetter adds some 0.01mm of error, what is your experience?

[edit] Your machine is waaaaay too clean :thinking::thumbsup:

Pablo


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## Rothrandir (Jul 27, 2008)

Definitely use the tool eye, it's just as accurate as setting the old fashioned way (cut and measure), maybe more so. A lot quicker too
The difference may be that mine is in good condition and never crashed, I've run machines where the tool eye will be off by .050". Even if you adjust the parameters to get it back in, they've seen such abuse that they're wobbly and will not repeat.


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## Bruceter (Jul 27, 2008)

Rothrandir said:


> Here is a picture of the softjaws cut to hold the tapered shank of a CAT40 tool, which might give you a better idea of how the softjaws are cut to shape to hold a part that would otherwise be impossible to hold:



What are you making the CAT holder blank into? That's a pretty good sized blank.

Bruceter


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## Rothrandir (Jul 28, 2008)

It was turned down so that a cutter body could be put onto it for a special application (I can't remember what now...)


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## Bruceter (Jul 28, 2008)

Thanks,

That is a nice looking arbor.

Bruceter


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