Chiff and Fipple Forums

glands:" I had hoped that sitting there wondering about the analogies would....well..... never mind. "
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...no no no, I liked the analogy....it seemed eerily fitting.... and some of the piper's expressions I have seen while they were playing makes it even that much more so.

Pipers expressions while playing......

I, for one, had the assistance of my wife to help me start out right. From day one, she would quickly point out when I was grimacing or making expressions in time with the music or in response to the demands of playing. As far as I know, I do not do that much if at all. I do seem to "zone out" when playing though. I could not speak in the middle of a tune without blowing it even if I had to say "call 911."

I've seen some pretty funny pipers faces. Some seem to be mouthing, huffing, puffing, and even pursing their lips while putting their chanters through octaves changes, into crans, etc. Of course, the "award" goes to a local musician who regresses to a hunched grimacing cro magnon-appearing individual when he gets out his bodhran and beats away...what'd you expect!

Piping faces. I have been trying to come up with a quasi-medical term in Latin that would translate as "piper's grimace".

Any help out there from you Catholic-schooled boys-n-girls? Or MDs?

t

Vultus contortus

PD.

Patrick D'Arcy wrote:Vultus contortus

Is that a spell from a Harry Potter book?

Love that little picture Patrick

John Mulhern wrote:Dunno, Reed, I don't think anyone's saying that gundrill's are necessarily better,...

OK, I am. And others have, in other forums. And on this one too, IIRC.

That's not to say that they work for everyone, but they have other advantages besides speed. Used carefully they leave glasslike surfaces that are much better than most people manage to achieve with twist drills. Whether that's due to lack of patience or an inherent limitation of twist drills or even D bits is a matter for some conjecture. However it's usually easy to tell the difference between a hole made with a twist drill and a hole made with a gun drill.

Also, it is important to buy a gun drill that is set up for soft materials like wood as opposed to metal boring, this may affect your results. When drilling wood you need more rake than you'd want for drilling steel.

They are also cheaper than was recently posted, some under $80 US.

- Bill

That's not to say that they work for everyone, but they have other advantages besides speed. Used carefully they leave glasslike surfaces that are much better than most people manage to achieve with twist drills.

Uh huh...and what happen's to your "glasslike" suface finish on anything requiring a tapered bore? It may be ideal for drone's...but obviously 99% of it is going to disappear during any subsequent counter drilling & reaming operation's on a chanter or reg's.

Also, it is important to buy a gun drill that is set up for soft materials like wood as opposed to metal boring, this may affect your results. When drilling wood you need more rake than you'd want for drilling steel.

I am curious about your drill geometry, Bill. The three Eldorado gundrill's I own (generic Ebay :roll: ) use zero degree back rake, and zero degree's (to my old eye's) radial rake.. Did Drillmaster's grind special positive rake into the tool for wood?, or more relief below the cutting edge?...or are you talking about the front cutting edge angle's? The regrinding spec's on the Eldorado shipping tube call for an offset point not centered at half diameter, but at 1/4 dia., the short cutting edge at 30 deg. angle, the long at 20 deg. Point angle recommendation chart's I've seen for HSS twist drill's drop from 118 deg. included angle (general purpose), to a much pointier 60 deg. included angle (wood), and even a -10 deg. auger design (also wood)...so I'm very curious what Drillmaster's came up with in this application.

John Mulhern wrote: I am curious about your drill geometry, Bill. The three Eldorado gundrill's I own (generic Ebay :roll: ) use zero degree back rake, and zero degree's (to my old eye's) radial rake.. Did Drillmaster's grind special positive rake into the tool for wood?, or more relief below the cutting edge?...or are you talking about the front cutting edge angle's? The regrinding spec's on the Eldorado shipping tube call for an offset point not centered at half diameter, but at 1/4 dia., the short cutting edge at 30 deg. angle, the long at 20 deg. Point angle recommendation chart's I've seen for HSS twist drill's drop from 118 deg. included angle (general purpose), to a much pointier 60 deg. included angle (wood), and even a -10 deg. auger design (also wood)...so I'm very curious what Drillmaster's came up with in this application.

Doug at DrillMarter is the best person to ask about details. But the last order I made used the standard "N-8" rake, actually:

and what Doug referred to as a 'modified Highland (probably R-4, "High land and top") contour:



The only other thing I note is that there's a .0015"/in backtaper, which might be more than is standard (to allow for some clearance and less "drag" as the tool cuts)

I use about 110 psi for these, but less pressure works ok if you watch the speed.

It's true that for conical bores, the speed of work and the limited drift you get with the gun drills is the primary advantage, since you're only step drilling anyway. But for drones, the surface finish left by the drill is certainly important.

Also, some flat pitch pipes can have drone bores of under 3mm for the tenor - I found it quite tedious to do that with a D reamer, and difficult to make a D bit that small, Maybe a more experienced machinist would have not trouble, but I have bored a long 2.7 mm hole with a D bit and with a gun drill, and I sure wouldn't go back to the D bit

- Bill

For wood:


For metal:


The tip of the one for wood:


The two side by side. Both of these are 5/32" diameter, 18" long, brazed into 2MT shanks.

Thanks David;

At first, the wood one looked as though it were ground totally at a diagonal with a negative rake like a scraper (top photo), but in the bottom ones it looks more "normal". Not sure how to interpret them still. I guess it's hard to see a 3d shape even in multiple photos.

The shapes I posted are the ones Doug/Drillmasters is recommending for wood boring, and said he is shipping to several pipemakers. Do you regrind your gun drills yourself? (the DM ones are carbide tipped)

DMQuinn wrote:For wood: Both of these are 5/32" diameter, 18" long, brazed into 2MT shanks.

Side air feed, I presume? I wish I had a lathe bed long enough to accommodate a MT shank at the end of the drill, I have to hand-feed.

- Bill