Gun drills - how much air pressure?

Ssonerai

AzB Silver Member
Silver Member
What kind of air pressure do you use in a gun drill?
They are made to take hundreds, if not a thousand PSI hydraulic for drilling metal, is let's say 100 - 120 psi air enough for wood?

Also, do you rotate the drill and the work, or just the work?
What kind of rpms?

Thanks!
smt
 

JC

Coos Cues
What kind of air pressure do you use in a gun drill?
They are made to take hundreds, if not a thousand PSI hydraulic for drilling metal, is let's say 100 - 120 psi air enough for wood?

Also, do you rotate the drill and the work, or just the work?
What kind of rpms?

Thanks!
smt

When it comes to air pressure/volume less is better. Just enough to keep the tip cool and evacuate the chips. RPMs more isn't always better either. I do it by feel. You can feel when the drill is cutting the easiest by tweaking both air and speed on the fly with the wood you're cutting. Kind of like adjusting the wire feed and voltage on a wire feed welder as you're welding your material of the day.

I have no idea how you might think of rotating the drill. You don't need to be an expert on things my papa always told me but you should know enough about it to ask good questions of those who are. Have you seen a gun drill setup?
 

Kim Bye

AzB Silver Member
Silver Member
You don't need much, I have a ball valve handle at my gun drill inlet, so I can adjust the air flow. 550 RPM works fine for me. I spin the work piece.
 
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cueman

AzB Gold Member
Gold Member
Silver Member
I run 50 psi and about a 1000 rpms. Only the work piece spins.
 

Ssonerai

AzB Silver Member
Silver Member
Well that's a relief.
Had visions of some sort of high pressure blasting away to get the chips out or it wouldn't work. Good to hear it's not that complicated. Also the ball park lower rpms suggested (500-ish) will work well with my set up.

I have no idea how you might think of rotating the drill. You don't need to be an expert on things my papa always told me but you should know enough about it to ask good questions of those who are. Have you seen a gun drill setup?

Obviously why i'm asking here - you guys know how it works in the wood whirrled, i haven't a clue.

There's 4 working lathes here but they are all small ones. (9 - 10"), short beds except the SB 10K tiny spindle 54" bed which "just" fits a cue butt or shaft between centers. So can either make this a long term project and plane up a long bed for gun drill use with a couple Hardinge headstocks at each end, one on a sliding section. Or, short term, add to my planer tooling/set ups. If the drill does not need to rotate, then a simple pivot holder to go on the toolslide to hold the drill and align it. On the table, Hardinge headstock with chucks on both ends. Bushing holder mount in front.

Basically, went to local surplus shop to get some small tools to modify for a 2 man chainsaw I am modding to take modern chain (make a new sprocket, build new clutch parts). They had racks of gun drills. Can you say kid in a candy store?

I keep reading on here about coring work.
As a woodworker, it makes perfect sense. Just never had a set up to do it. So getting advice and working that direction.

Several people contacted me about 6 point FS rosewood/curly blank that really needs cored, so that is current initiative. Though in a long line of other projects, sigh.

Thanks for the advice!

smt
 

JoeyInCali

Maker of Joey Bautista Cues
Silver Member
35 PSI is all you need .
600+ RPM .
As JC mentioned, you have to feel the action.
Tung oil or BLO on the gun tip does wonders. You're welcome everyone .

6-jaw chuck gives a better grip.
Supporting the back end with a pvc chucked up on the rear lathe does not hurt.
 

Mcues

AzB Silver Member
Silver Member
About 30 to 35 psi and 525 to 600 rpm depending on the type of wood, how the chips are clearing and the heat created. The drill is supported by a center rest with a bearing and
sleeve.


Mario
 

63Kcode

AKA Larry Vigus
Silver Member
I have a regulator on my gun drill. Don’t have a gauge on it. If the air coming out of the cue feels warm. I turn up the pressure till it’s cool again. Different woods required more air pressure than others. Some woods drill better at different rpms too.

Larry
 

Ssonerai

AzB Silver Member
Silver Member
Thanks to everyone for the continued advice.

I do have a portable/quick connect manifold with valves and regulator that is used with various pneumatic devices and clamps here, so that should take care of air control now that it is clear not much pressure is required.

Make sure your drill has a sharpened wood cutting profile

Drat.
Just when it was all sounding too easy.
:D

No doubt when time permits, I'll try it with the fresh re-sharp grinds already on the tools and see how it goes. Meantime, searching for sharpening data, not finding anything specific about wood geometry. Picking up a lot of other related info, though.

Thanks!
smt
 
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GBCues

Damn, still .002 TIR!
Gold Member
Silver Member
SMT,
I remember that discussion, it was here or over on Cue Machinery and Supplies. I think Joey Batista aka Joey in Cali (or something like that) was involved. It was pointed out that if you sent your gun drill back to Sterling (I think) for re-sharpening you could tell them it was for wood and they knew to grind a different edge on. However, it doesn't mean you can't cut wood with the edge that they come standard with.
Anyway, you could try your search skills and see what you can find.
Good luck,
Gary
 

JoeyInCali

Maker of Joey Bautista Cues
Silver Member
SMT,
I remember that discussion, it was here or over on Cue Machinery and Supplies. I think Joey Batista aka Joey in Cali (or something like that) was involved. It was pointed out that if you sent your gun drill back to Sterling (I think) for re-sharpening you could tell them it was for wood and they knew to grind a different edge on. However, it doesn't mean you can't cut wood with the edge that they come standard with.
Anyway, you could try your search skills and see what you can find.
Good luck,
Gary
When you order a gun drill from Sterling, you need to tell them it's for pool cue or flute.
I don't know if they regrind different kind of drills.
 

Ssonerai

AzB Silver Member
Silver Member
When you order a gun drill from Sterling, you need to tell them it's for pool cue or flute

Not to be a smart axe but i just don't feel compelled to shop new very often for tools.:)
If specs on the geometry don't turn up between now and when needed, i'll call them or one of the others and maybe one of them will send a print.

I do appreciate the advice that different grinds for wood are common. (As opposed to say, twist drills where it barely matters.)

smt
 

BarenbruggeCues

Unregistered User
Silver Member
Not to be a smart axe but i just don't feel compelled to shop new very often for tools.:)
If specs on the geometry don't turn up between now and when needed, i'll call them or one of the others and maybe one of them will send a print.

I do appreciate the advice that different grinds for wood are common. (As opposed to say, twist drills where it barely matters.)

smt

I hold mine in my hand and run it up to the grinding wheel for resharp.
Seems to work just fine for me. ;) It's just not that technical.
Put an edge on it and bore away. You'll know if you have a sharp edge on it or not once you get started.
Oh yea....make sure your dust/chip catcher turned on full suction....you're gonna need it! :grin:
 

Ssonerai

AzB Silver Member
Silver Member
I hold mine in my hand and run it up to the grinding wheel for resharp.
Seems to work just fine for me. It's just not that technical.
Put an edge on it and bore away. You'll know if you have a sharp edge on it or not once you get started.
Oh yea....make sure your dust/chip catcher turned on full suction....you're gonna need it!

Whoa!
That would save a lot of money.
& make a great youtube video. :thumbup:

One of the best T & C guys i knew in early daze did some backing off that way. You too? Or the whole grind?????

I need crutches. Cincy #2 & fixtures; or one of the surface grinders here + same.

smt
 

JoeyInCali

Maker of Joey Bautista Cues
Silver Member
I hold mine in my hand and run it up to the grinding wheel for resharp.
Seems to work just fine for me. ;) It's just not that technical.
Put an edge on it and bore away. You'll know if you have a sharp edge on it or not once you get started.
Oh yea....make sure your dust/chip catcher turned on full suction....you're gonna need it! :grin:
I need a video tutorial
 
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Ssonerai

AzB Silver Member
Silver Member
Wasn't Dennis Dieckman Mr Barrenbrugge's mentor?

It's easy to imagine Dennis in some old video pontificating on the subject and adding something like "Green wheel's good enough, too, don't need no steenkin' diamonds!" :D

The thing is, if he would have ever posted such a thing, he could probably do it.

smt
 

Kim Bye

AzB Silver Member
Silver Member
Those CBN grinding wheels have come down in price quite a bit the last years. Considering how fast you make that money back when you can grind your own tools, it`s money well spent.
 

JoeyInCali

Maker of Joey Bautista Cues
Silver Member
Those CBN grinding wheels have come down in price quite a bit the last years. Considering how fast you make that money back when you can grind your own tools, it`s money well spent.

Damn, now you're gonna make me spend money.

Not gonna use that on my carbide tipped gun drill though.
But, the parting tools, drills and lathe bits could use some sharpenin'.
 
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