Without going to the expense of having a custom bit machined, what approach would you use to drill a tapered bore in a wooden whistle finger tube?
John
On 2002-12-26 17:37, Elkcreek wrote:
Without going to the expense of having a custom bit machined, what approach would you use to drill a tapered bore in a wooden whistle finger tube?
John
Elkcreek, I see you’re a cabinetmaker.
It ain’t gonna happen.
Hopefully you didn’t take my previous post as a rude answer, but… You’re asking to drill a tapered hole in a dowel that is probably 14-15" long and you want to do it using a straight bit so as not to incur expenses for a tapered bit. What kind of accuracy do you want to acheive?
A computer controlled Laser boring tool could do it. A steel stepped drill bit might give you a chance. A hardened steel tapered reamer would probably be the correct tool of the trade. Now where talking conical bore instruments.
I don’t see any other way to accomplish the task.
What about approximating a tapered bore? Start with a ~5/8", go down a 16th every few inches and end up with 7/16.
Of course, then you’re talking about several really long bits, and it would probably cost no more to get a single tapered bit.
Tony,
I didn’t think your answer was rude. I have tried a few approaches and come up with the same answer myself. 
I do know though that when I confront a problem like this, that thinking of solutions in terms of technology that is available to us today can sometimes overcomplicate things and stand in the way of arriving at a solution. This can be particularly true if someone doesn’t have hundreds of dollars to throw at a “whimsy” project.
When a question like this is put in front of people sometimes some pretty interesting answers pop up from individuals that don’t have preconceived ideas of what is and is not possible.
My father always told me that you couldn’t put a square peg in a round hole. As it turned out doing that very thing has been an extremely effective method of counteracting the forces of modern heating and air conditioning on hardwood furniture.
Any ideas on how this was done three hundred years ago? How about three thousand years ago?
I just wanted to bait the hook and throw it in the water to what bit.
John
Charlie,
I was thinking about that. Then finishing the taper in the hole with an abrasive rod that was made in the shape of the final cut of the bore. Thanks for the input.
John
On a metal lathe, take a dowel, put it in the chuck with a steady rest at the flying end. I have used bees wax and a light-weight oil to make the wood vs. rest friction tolerable. Take as much out with a straight bit. Then, assuming that you have a taper attachment for your lathe, use a boring bar instead of a bit. Cut as far in as possible, then re-seat the boring bar at the new depth (this assumes that you have a taper attachment not capable of feeding 15"). It’ll get a bit jumpy once your bar get’s fully extended, but…
That’s one way, anyway
Erik
c’mon Erik… what are the chances of repeating that procedure on the second prototype?
It ain’t gonna happen…
(note: I don’t speak that way in real life)
Well, except for the error caused by such a long boring bar, I’d say that you could repeat it within a tolerable margin of error (couple hundredths?). This can be adjusted for by where you cut your tube for the final lengths since my assumption here is that you’re not working with your finished lengths. (post edit: seems to me like the main issue is the degree of taper which should be consistent enought for playing around - I never said that I’d do it this way for production work )Depends upon your setup, but it isn’t that far out.
E
[ This Message was edited by: ErikT on 2002-12-26 23:13 ]
OK, tapered bore… allow the wood to season a few months longer after initial reaming. Recheck the bore, possibly ream again if the wood ‘moved’ from the first pass. Trim ends at the proper opening & length. Voila!
Drilling a deep, STRAIGHT, non-tapered hole without coming out offcenter is tough enough! I recently bought a fantastic gundrill to do the job. It was expensive, but really does the trick. This thingie has a carbide tip, and an air channel down the middle, with an adaptor fitting for an air compressor ( which I also had to buy). Once I have the piece of wood set up as Erik described, with a ball bearing steadyrest, I can drill the 7" long hole in the body section of a whistle in considerably less than a minute. The compressed air ejects the chips, and keeps everything nice and cool so as not to cook the wood. Sweeeet!
Paul, what are your steps?
Drilling first to find center then turining the 1x1 ? or turning the 1x1 and boring it after?
(slightly befuddled look on Feline face)
Tim Allen, where are you when we need you?
Actually, I’m finding this thread strangely stimulating…in a foreign film sort of way.
First some discussion. Most tapered-bore instruments were made (pre CNC) by doing a straight bore (simple taper) or multiple bores (curved taper) then reamed to shape with a tapered or belled reamer. Contrary to what seems to be implied here, those are not that difficult to make. They can be fabricated from metal or wood, though they must have metal or carbide blades.
Were I going to do this, I would make a 3-bladed reamer, using 5/16" or 3/8" round mild steel rod for the shaft, and HSS for the blades. Instead of turning a tapered shaft and using straight blades, I would use the blades to form the taper. Beginning with 3/32 HSS stock, I would first anneal it by heating and allowing to cool slowly, then cut out the blade triangles on the bandsaw. Clamp and mill the mounting edges on the blades, then set the cut angle on the mill, and mill the blade’s cutting edge. Go a bit (0.020") oversize to allow for sharpening and fine-tuning the edge. Add 0.05" to the height to allow for setting into a channel.
With the round rod clamped,mill a 3/32" slot down the length, 0.050" deep. Rotate 120 deg and mill another identical, repeat 1 time.
Flux the channels and the mounting edge of the blades, and file brazing rod lightly into the channels. Set the blades in the channels and bind with iron wire, being careful to keep the blades seated at 90 deg to the perpendicular tangent.
Flux the join edges with a paste made of brazing flux and brazing rod filings.
Place the assembly in a small oven made from insulating refractory brick, and bring to brazing temperature, preferably with gas burners, due to excessive warmup times with electric. Allow to cool very slowly to avoid warping. Remove and inspect, then replace in the oven.
Bring the assembly to low red heat, and remove from the oven. Observe the colour as the piece cools. When you see the HSS bits turn straw colour, quench the assembly in oil.
Final grind and lap the cutting edges, and you are ready to use your reamer.
You can make this a little more easily by substituting a stable hardwood dowel and epoxy for the steel rod and brazing. It will not be as durable, but it will work.
Next up: The Really Easy Way…
Serpent
Ala Elk Creek’s suggestion, but with a small twist – Turn a wooden rod down to just a bit smaller than the bore should be. Using feathering disc adhesive, stick progressively finer sandpaper cones over the rod and spin it inside the bore. Replace the sandpaper as needed. Be careful not to get it jammed.
The tapered reamer is the best idea, but I don’t think I’d go to the trouble unless I planned to do it commercially.
Cheers,
serpent
Did you catch all that tyghress?
Tyghress, it is rather heady stuff, isn’t it? 
Andrea ~*~
here’s some historic futes.
to give you a beter idea of how thay were made
http://www.music.ed.ac.uk/euchmi/uwl.html#Woodwind
… Laser boring tool … steel stepped drill …hardened steel tapered reamer
metal lathe…with a steady rest at the flying end…bees wax and a light-weight oil to make the wood vs. rest friction tolerable…taper attachment for your lathe…boring bar …taper attachment not capable of feeding 15"…It’ll get a bit jumpy once your bar get’s fully extended
after initial reaming. Recheck the bore, possibly ream again if the wood ‘moved’ from the first pass
fantastic gundrill …This thingie has a carbide tip…air channel down the middle, with an adaptor fitting …ball bearing steadyrest…
tapered or belled reamer…using 5/16" or 3/8" round mild steel rod for the shaft, and HSS for the blades…first anneal it by heating and allowing to cool slowly…Flux the channels …Set the blades in the channels and bind with iron wire, being careful to keep the blades seated at 90 deg to the perpendicular tangent…insulating refractory brick…quench the assembly in oil…grind and lap the cutting edges… feathering disc … progressively finer sandpaper cones over the rod and spin it inside the bore…Be careful not to get it jammed
Guys, I don’t think I’m supposed to be reading stuff like this at work! (fanning my fevered brow)
T, it’s Ok to READ it, just not Ok to DO it.