"Eric R Snow" wrote in message
news
On Tue, 8 Feb 2005 18:03:14 -0500, "ATP*" wrote:

For the drills with the oil feed holes parallel to the shank, which run
from
one end of the drill to the other, is a different bushing made for every
diameter of drill? Also, is the oil fed under pressure? I was
contemplating
settting up something to use oil-fed drills in the tailstock of my lathe.
I'm finding a lot of stuff about the drill bits themselves, but not much
on
the equipment needed to run them. TIA.

It appears that you are describing a gundrill. If this the case the
yes, a bushing is used for every drill size. This bushing guides the
drill point as it enters the work and must touch (usually) the surface
of the work. The shanks for different groups of sizes of drill are all
the same size where the drill is mounted in the spindle. The oil
pressure can be up to 3000 psi. The oil forces the chips out of the
hole and actually supports the drill when the drill is a small
diameter. If you are seeking information about a different kind of
drill please post a link.
ERS

I'm not looking at anything as long as a gundrill, just at practical ways of
feeding coolant through 9 or 10 inch long 1/2 inch drill bits, for example.
After doing some searches on coolant collets, I think I'm beginning to
understand the setup- I have seen endmill feeds with oil rings, dedicated to
one size, this would obviously be rather expensive for the many drill bit
diameters one might want to use. I'll keep an eye on ebay, it seems the
complete chuck/collet setup is not a real common, inexpensive item.

Thanks to all who replied.