Probably A Stupid Question About A 4 Jaw Chuck

[ShinerTX]

Hi again everyone,
Probably a stupid question, so please try not to laugh,
I am in the middle of installing a Köping S10C lathe into my shop which was given to me by a friend who has owned it for many years. I'm re-powering it, etc, all of which is on another thread and photo album that I just created and is pending approval. Anyway, the lathe is big... 10" swing, and came with a massive 4 jaw chuck.
I like 4 jaw chucks... The diversity is great and I really never had much of a problem centering work... I'm slow, but eventually get there. I do occasionally have a need for a 4 jaw...but typically most of my work is smaller, however, and doesn't require the holding power or off center features of the 4 jaws.
Is it considered bad to chuck a smaller 3 jaw in the 4 jaw and use that? Changing the chuck is not impossible, just a pain, heavy as all get out and expensive. I'm just looking for ways to make this big lathe more user friendly for my work without breaking the bank. My work isn't that dimensionally critical.
Thanks in advance. I love this site and forum... Learning lots...
Jim

 

[JimDawson]

Just kidding, there are no stupid questions on The Hobby Machinist

I have seen that done. Not as robust as mounting the 3-jaw on the spindle, but there is no reason it won't work.

 

[mksj]

Yep, that is a big 4J. Might ultimately consider a smaller chuck if you do not need that large a swing. If you have a chuck, you should only need some type og adapter plate to the spindle mount. You may see some more angular TIR mounting one chuck within another, you also have all that spinning mass near your hands if you are doing something small close in. It is not uncommon to use a collet holder in a larger chuck for turning small stuff, like a 5C or ER-40.

 

[ShinerTX]

Thanks for the replies. In my search for info on the Köping lather, I googled them and there was a video of someone testing a S12C that had a 3 jaw chucked into a 4 jaw, which got me thinking (and posting). I'm still researching and getting to know this machine, I've got no idea if the spindle mount for the chuck is standard, or some weird Sweedish size or thread.
Thanks again,
Jim

 

[dlane]

30hp motor on a 10" swing lathe , someone please approve that thread , my 10" swing SB 10L has a 3/4 hp in it .

 

[ShinerTX]

Your welcome to question it... But it is indeed a whopping 30 HP, 380 Volt 3 phase motor that was on it, verified by the machine manuals and motors data plate. It ain't no Southbend... Köping built 3 models of the same lathe, an S8C (8" swing) a S10C (10") and the S12C (12") They are extremely rigid, heavy machines capable of deep cuts. This thing weighs a little over 8000 lbs.

 

[JimDawson]

30hp motor on a 10" swing lathe , someone please approve that thread , my 10" swing SB 10L has a 3/4 hp in it .

I think that is what we would call a 20 inch swing. European lathes are measured by the swing radius, rather than the diameter. But still....30hp is a lot of motor! That is one heck of a machine!

Would look really good sitting in my shop

 

[ShinerTX]

That is correct, it'll turn a 20" diameter piece.

 

[Tozguy]

Your welcome to question it... But it is indeed a whopping 30 HP, 380 Volt 3 phase motor that was on it, verified by the machine manuals and motors data plate. It ain't no Southbend... Köping built 3 models of the same lathe, an S8C (8" swing) a S10C (10") and the S12C (12") They are extremely rigid, heavy machines capable of deep cuts. This thing weighs a little over 8000 lbs.

Would you have a link to your thread on repowering this lathe?

 

[4GSR]

Like others have said, and I've done it myself and still do at times, put a smaller three jaw in the 4-jaw chuck or even a smaller 3-jaw in a larger 3-jaw chuck.
If and when you decide to mount a 3-jaw chuck on your lathe in place of the 4-jaw. I have a 12" Bison Set-Tru chuck here I'll sell to you. Won't have to worry about shipping, just a 45 mile trip to Victoria to pick it up or I could bring it up to you. It currently has a L-1 mount but can be removed and any adapter put in it's place. Ken

Edit: Lets see, if I come up there to Shiner, I could go over to the brewery and drink some Shiner Brock while I'm there. Wonder if they have some Shiner Strawberry Blonde at the brewery?