# How can I know if a chuck will fit my Logan?



## strantor (Feb 11, 2013)

I've got a logan 9B, came with only a 4-jaw chuck. I'd like to find a 3-jaw for it. It has a 1-1/2" 8TPI spindle. I have found chucks with the proper thread pattern but they are pricey. I can find cheaper chucks like this one for example all day long, but they require a back plate. My 4-jaw DOES have a back plate, but I'm unsure if the bolt pattern and overall design is universal. I am leery to buy one of these cheaper chucks for fear they won't work with my backplate. 

Can someone please tell me if these backplates are universal, or otherwise direct me to an inexpensive (hopefully under $150-200) self-centering 3-jaw chuck that is guaranteed to work with my lathe?

Thanks,
Strantor.

P.S. My back plate has 4 bolts, that are 4.5" apart, measured across the gap.


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## Alan Douglas (Feb 12, 2013)

Wouldn't the chuck be mounted on the back plate permanently?  If you bought a new chuck you'd buy a 1 1/2-8 back plate at the same time.  At least that's how my Logan chucks are set up.


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## jester69 (Feb 12, 2013)

Tools4cheap has a 6" 3 jaw with 2 piece jaw with 1 &1/2 x8 back plate for $ 168.00

Rick


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## swatson144 (Feb 12, 2013)

The back plates are far from universal. You can get "semi finished" back plates which only require cutting the spindle register and cutting the chuck register fairly cheaply ~ 100$. You can get the 2 together with the back plate fitted to the chuck cheaply for imports. The best answer for a 3 jaw to me is to buy a good used chuck and order a semi finished backplate which is bored and threaded. You cut the spindle register with your 4 jaw then mount it on the spindle to face and cut the chuck register so that everything comes out square on your lathe. 

It don't matter on a 4 jaw since you end up centering the work in it.

Steve


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## strantor (Feb 13, 2013)

Alan Douglas said:


> Wouldn't the chuck be mounted on the back plate permanently?  If you bought a new chuck you'd buy a 1 1/2-8 back plate at the same time.  At least that's how my Logan chucks are set up.


definately not permanent, on my lathe at least. I just separated the two, held together by 4 bolts. maybe mine isn't original?


jester69 said:


> Tools4cheap has a 6" 3 jaw with 2 piece jaw with 1 &1/2 x8 back plate for $ 168.00
> 
> Rick



just googled that, and looks like a great find. the description rings a clear bell. I know for a fact that I've seen that description on an ebay listing. I can't find it now, and it's not in my watch list, which means it was listed for >$200. Maybe someone is reselling Tools4cheap's products.


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## prmindartmouth (Feb 14, 2013)

Here is the $168 chuck with back plate on tools4cheap's web site:
http://www.tools4cheap.net/proddetail.php?prod=3jawthreadchuck2pc

He notes some machining is required on the back plate!


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