# Can i fit a 8" 4 jaw on my logan 11"?



## ome (Sep 27, 2013)

Hi guys, 
I just got my 6 inch 3 jaw on the lathe, and measuring, it looks very close for a 8 inch when the apron and saddle is brought up close to the spindle. 
I had wanted a 6", but buck co stopped making a 6" with reversible top jaws, only solid jaws. 
Any advice as always is greatly appreciated. 
Thanks,
jon


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## Tony Wells (Sep 27, 2013)

I'll give you a good, solid......maybe. The decision should probably include some thought about how far the jaws will protrude when chucking something of a reasonable diameter for an 8" chuck. Try not to focus strictly on the body of the chuck.


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## mclarenross (Sep 27, 2013)

On my 11" Rockwell I only use 6" chucks. That is not to say an 8" wont fit and wouldnt work but the carriage hits an 8" chuck body and I dont like not being able to get the carriage under the chuck.


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## ome (Sep 27, 2013)

mclarenross said:


> On my 11" Rockwell I only use 6" chucks. That is not to say an 8" wont fit and wouldnt work but the carriage hits an 8" chuck body and I dont like not being able to get the carriage under the chuck.


If i were to settle on a 6" 4 jaw without reversible jaws, is that make a huge difference?
thanks
jon


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## TomS (Sep 27, 2013)

There was a similar thread on this site a couple of weeks ago with a lot of good feedback.  To answer your question; yes, you can fit a 8" chuck on your 11" Logan.  Not sure you will like the results though.  As pointed out you may be restricted on the distance the chuck jaws can stick out past the body.  Another consideration is weight of the chuck.  An 8" chuck weighs considerably more than a 6".  How do I know this?  I have a 6" three jaw and an 8" four jaw for my 12 x 36 lathe.  It won't be long before I'll need some sort of lifting assistance to change out the four jaw.  The four jaw weighs nearly twice the 3 jaw.

Good luck in your search for a new chuck.  There are many to choose from that will meet your needs.

Tom S


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## 4GSR (Sep 27, 2013)

I have a 8" 4-jaw on my 9" SBL.  It has served well over the years I've ran it.  But it is a very light duty chuck which is perfect for the 9".  Never had a problem with the jaws hitting the bed ways, come close though!

But not all 8" chucks are the same.  Get a old school Cushman 8" chuck, with heavy thick jaws, you would not even think of putting that on a 9" lathe.  11" Logan, it might work.  Some of these 8" 4-jaw import chucks should work fine on a 11" lathe.  They appear to be of a light to medium duty use.

I believe in putting the largest chuck you can on your lathe.  But the jaws can create problems if not thought out thoroughly.


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## itsme_Bernie (Sep 27, 2013)

4gsr said:


> I have a 8" 4-jaw on my 9" SBL.  It has served well over the years I've ran it.  But it is a very light duty chuck which is perfect for the 9".  Never had a problem with the jaws hitting the bed ways, come close though!
> 
> But not all 8" chucks are the same.  Get a old school Cushman 8" chuck, with heavy thick jaws, you would not even think of putting that on a 9" lathe.  11" Logan, it might work.  Some of these 8" 4-jaw import chucks should work fine on a 11" lathe.  They appear to be of a light to medium duty use.
> 
> I believe in putting the largest chuck you can on your lathe.  But the jaws can create problems if not thought out thoroughly.



+1 Here.

I have a SB Heavy 10.  
I have an "old school" Cushman 6 inch chuck, and I have to hold it really well to get it on the spindle carefully.  HEAVY.  
I had a sweet 8 inch 4 Jaw, made by SOUL, from Japan.  HEAVY.  I sold it.  It was just such a deterrent to put it on, and it was so big.  I thought I might find a use for it once in a while, but then you have to watch the carriage and even the lathe ways when the jaws are opened wide!! 


Bernie


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## yugami (Sep 27, 2013)

My logan 11 came with an 8" chuck.  It fits, but barely.  As everyone already pointed out you don't really get any increase in capacity due to jaw stick out issues.

So its heavier, harder to get on/off and doesn't get you anything.


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## Bill C. (Sep 28, 2013)

mclarenross said:


> On my 11" Rockwell I only use 6" chucks. That is not to say an 8" wont fit and wouldnt work but the carriage hits an 8" chuck body and I dont like not being able to get the carriage under the chuck.



Good question, its been my experience if you open any chuck to where the jaws extend passed the outside diameter of the chuck body and the jaws don't hit the ways then I would use it.  You can screw the compound slide in as far as it can go then move the tool post to the leading edge. I have setup a few jobs this way. Usually the part isn't very long but wide. Likely a steel plate that needs boring. Good luck


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## Bill Gruby (Sep 28, 2013)

I have an 8 inch Cushman on my 9X20. It has no issues at all.

 "Billy G"


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## Hawkeye (Sep 28, 2013)

Two things that help. Always spin the chuck by hand before turning on the power. And always set your carriage stop so that nothing can move into strike position while it's running. No carriage stop? Add it to your project list. Too useful not to have.


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## tomb29 (Sep 29, 2013)

I have an 8" 4 jaw on my 10" south Bend and have never had a problem. I don't ever recall having to get my carriage under the chuck for any reason and it isn't so much that you can get almost the same capacity out of a 6 inch it is that you have to have the jaws that much further out of the chuck to grab a large object. It all has to do with overloading the capacity of the work holding device. When putting the chuck on and off it is advisable to put a piece of say 3/8 or 1/2 inch plywood on the ways so as to not ding them up if you should happen to slip and if weight is a problem (as it is with all of us old timers) I put a small block and tackle set up from the ceiling right over my lathe so I can lift whatever I want up to the spindle or chuck.
Tom B


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## ome (Sep 30, 2013)

Hawkeye said:


> Two things that help. Always spin the chuck by hand before turning on the power. And always set your carriage stop so that nothing can move into strike position while it's running. No carriage stop? Add it to your project list. Too useful not to have.


Thanks,
Will any carriage stop fit my logan 11' lathe?
Thanks again,
jon


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## ome (Oct 2, 2013)

Bill Gruby said:


> I have an 8 inch Cushman on my 9X20. It has no issues at all.
> 
> "Billy G"


Thanks,
new like a few years old or older like pre 2005
Thanks,
jon


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## Hawkeye (Oct 2, 2013)

ome said:


> Thanks,
> Will any carriage stop fit my logan 11' lathe?
> Thanks again,
> jon



Any carriage stop you make will fit the lathe. Not hard to make. I made mine from a piece of 3/4" square aluminum bar, with a notch to fit the V on the front of the lathe bed. It has a 3/8" hole with a setscrew for a dial indicator and a solid stop.


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