On Thursday, January 23, 2020 at 2:57:57 PM UTC-5, Gunner Asch wrote:
On Tue, 7 Jan 2020 00:26:50 +0000, David Billington
wrote:

On 06/01/2020 21:46, wrote:
On Mon, 6 Jan 2020 13:15:59 -0700, Bob La Londe
wrote:

On 1/5/2020 10:50 AM, Bob La Londe wrote:
Ok, my previous deep drilling operations went off pretty well. Carbide
3 flute drills worse used on a couple of them. One to start holes for a
hand ground split point, and the smaller hole with just a carbide jobber
drill. Both actually met up in the middle close enough. One for a
hinge pin and the smaller one for an injection cavity feature. They
worked. Didn't actually do any gun drilling.

Now I am looking at an application that will need to drill straight
(size is not highly critical), for from 20 to 28 inches for a water
jacket.
The only machine i have I think would be suitable for it is the 14x40
engine lathe. Throwing a 20x30 inch piece of plate on the chuck is
obviously not the answer. LOL. I was thinking to use some sort of tool
holder in the spindle, and make a mount and support for the plate on the
carriage. After doing a bit of reading gun drilling does not just use
hydraulic pressurized oil. It is also done with pneumatic air mist
under pressure. Now the trick I think is to figure out how to
pressurize a spinning gun drill inside a lathe spindle. I have some
ideas, but they are kind of vague at this point.

The thought of buying and setting up a dedicated machine down the road
is not out of the question. Right now I am looking for the shade tree
get it done short term solution.
I think I have most of it figured out if using the lathe is the answer.