Gun Drills & Whistle Tube Boring

 1/2" Gun Drill

1/2" Gun Drill

I have had several folks ask how I manage the long straight holes for the whistle bores. The answer is "Gun Drills". The drills are used (as the name suggests) in the drilling the bores for rifles/shot gun barrels.

The 1st photo shows the 1/2 inch drill that use in the construction of E, E-flat, D and C whistles. The drill is shown mounted in the lathe tail stock drill chuck. The ruler/scale shown is 12" in length. The photo also shows the air hose that supplies the high pressure air required in the use of this drill.

 Drill Cutting Face

Drill Cutting Face

The need for such a drill comes from need to clear the chips, generated in the drilling of long holes, without having to repeatedly remove the drill from the hole to do so. The gun drill accomplishes this by sending the high pressure air (85 psig in my usage) down a hole in the center of the drill shank. The air exits at the drill face sending the chips back down the drill shank via a large 90 degree clearance section removed and running down the length of the drill shank. This air hole and 90 degree removed section can be seen in the second photo of the drill cutting face.

 Composite Gun Drills

Composite Gun Drills

Due to the need to increase the bore size as the whistle basic pitch is lowered, different size drills are required. As mentioned earlier, I use a 1/2" drill for my E, Eflat, D and C whistles. My A and B whistles use a 9/16" drill, my F and G whistles use a 5/8" drill and my low octave D whistles use a 7/8" drill. They are shown, bottom to top , 1/2', 9/16", 5/8" and 7/8"

The photo below shows the 1/2" drill mounted in the lathe tail stock and a whistle tube mounted in the lathe headstock 3 jaw chuck. While not too obvious, it also demonstrates the limitations of my equipment in the maximum allowable length of whistle tubes.

 Gun Drill Mounted

Gun Drill Mounted

The required length of the drill, the length of the tail stock drill chuck and the maximum length of the lathe bed, limit the length of the whistle tubes I can drill to about 10". This means I have to build the lower pitched whistle (which require longer tubes) with 2 part tubes. Photo 5 is a shot of one of my Octave D whistles. The tube is separated between the F sharp and G tone holes. The time, materials and effort to bring all of this about really runs up the cost of a whistle and has really limited my desire to build them.

Well, that's about all I can say about gun drills. Well again, if anyone has anything they would like me to discuss let me know!

 Low D Flute

Low D Flute