Maximum Stock overhang without support in 3 or 4 jaw chuck.

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rfdes

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Is there a rule of thumb for determining the acceptable allowed overhang from the chuck before one would need to use a steady rest and/or tail-stock?
It seems like I have heard something like 3 times the diameter of the stock (or similar). i.e. if you had a 1" dia piece of stock, the stock shouldn't be any longer
than 3" sticking out from the chuck.

Does this sound about right? I could use some guidance here.
Thanks
Jim
Largo, Florida
 
rfdes said:
Is there a rule of thumb for determining the acceptable allowed overhang from the chuck before one would need to use a steady rest and/or tail-stock?
It seems like I have heard something like 3 times the diameter of the stock (or similar). i.e. if you had a 1" dia piece of stock, the stock shouldn't be any longer
than 3" sticking out from the chuck.

Does this sound about right? I could use some guidance here.
Thanks
Jim
Largo, Florida
Click to expand...

3:1 is an excellent ratio (rule of thumb), the material itself plays a leading role in that dance as does the machine/tooling, the work being done plays a more substantial role.

The type of work that can be done well that far out in steel, light OD turning/boring, center drilling and facing.
Plastic materials that are not free cutting are a problem.
Aluminum, depending on the alloy and cutting conditions can go either way.

That being said, I have no problem lightly facing a 1" part 5" or more out, I would not try and part it more then 1/2 the diameter from the jaws or collet, that is just my experience.

Your mileage may vary, good luck
 
My old atlas book says to not go over 4 or 5 times the diameter of the stock. Material, feed, depth of cut, and sharpness of your tool makes a difference. I generally try to stay in the 3 to 5 range with floppy material closer to 3 and stiffer out to 5. I also try to use the tail stock for most operations. Things go better with rigidity.
 
Thanks for the input. I will go with your recommendations and see how she goes...
Take care -
Jim
 
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