CHUCK JAW PRESSURE 2

[AESBOB]

HI

DOES ANYBODY KNOW HOW MUCH PRESSURE IS APPLIED
TO A MANUAL CHUCK JAW (3 JAW AND 6 JAW CHUCKS)

THANKS AESBOB

 

[cncprogrammer]

Aesbob,

Don't know how much pressure is applied. Never had a problem with parts wanting to come out. There are clamp pressure measuring devices available.

David

 

[EdDanzer]

It will depend on the make of chuck, size and the RPM it is operating at. We have a wedge chuck that can be set with a torque wrench for clamping force.

 

[metman]

This might be oversimplifying but I think it is a matter of proportional mechanical advantage as follows: Set the jaws open at 1' diameter, turn the chuck T-handle ten revolutions and measure the jaw opening. Let's say your T-handle is (10" long X 3.14/rev) X 10 rev's = 314" travel. Let's assume the jaw opening ended at 3" dia or total radial jaw movement of (3-1)/2 = 1. The ratio is 314/1 = 314:1. If you can exert 25 lbf at each end of the handle using both hands, 50 X 314 = 15,700 lbf at the jaws.

This number seems too large so somebody please blow holes in my analysis.

Jesus is THE life,
Leonard

 

[EdDanzer]

Metman,
Friction will reduce the gripping pressure.
The gripping force will depend on the type of chuck, scroll chucks have less grip than wedge chucks. An independent jaw chuck’s grip will be different than either scroll or wedge.
If chucking pressure is important, contact the manufacture and get their published information, or have the grip checked with a force measuring tool.
As the RPM the chuck rotates at increases, the gripping force will go down, unless you have a counterbalanced chuck.

 

[jlhmaint]

did some studies at my last job alot of information is on the web and each chuck is different. Find out what type of chuck you have and look up there site or call them. this is the safest and best way to be sure.