Does anyone know of a good way to make a conical bore 15"

[tyiam]

I am in the process of making a (exotic hardwood) Conical Bore QUENA FLUTE.

Do you know of a way to drill a Conical Hole 15” long . That has a tapered hole that is 3/4” ID at the top... and 1/2” ID at the other end.

I would appreciate any insights or information you may have related to this process.
Many Thanks -Ty

[wizzywig]

From what I have heard from flute makers, they use tapered reamers, reducing the bore gradually. Ask any flute maker for details.
wiz

[brewerpaul]

From what I have heard from flute makers, they use tapered reamers, reducing the bore gradually. Ask any flute maker for details.
wiz

You mean increasing the bore. You'd drill the bore the diameter of the smaller exit hole at the foot, then ream out to the larger diameter at the head end of the flute. This would probably involve custom made reamers.

[Feadoggie]

Ty,

You can look at various flute making sites as well as recorder making sites for what other makers do. Here's the procedure I like. Drill an undersized pilot hole the length of the blank. Then step drill in sections to remove additional material while not exceeding the final bore size at any point. Use the pilot hole as a guide for the step drills to keep things on center. You can use as many steps as make sense for you. Then use your reamer to finish the bore to size. Most flute and recorder makers will utilize self-made reamers but if you can find appropriately sized tapered reamers you could use commercially made cutting tools. Building the flute in sections can help too, IMO. Luc Verhoven has a good website which illustrates his flute making procedures. He shows how he shapes his tapered bores there.

Feadoggie

[JackCampin]

Quenas aren't usually conical. They have a narrowing on the end (bamboo node or stuck-on washer-like disc) to narrow the bore and simulate the effect of a conical bore.

[Thomas-Hastay]

True, traditional Quenas are made to simulate a conical bore by making a reduced bore end hole in a natural bamboo "node", but a professional instrument would require a tapered bore for acoustic superiority.

I suggest drilling a 1/2" bore first and then using a tapered "Reamer" (shell reamer) to expand the top of the bore to 3/4". This can be done with a open ended steady rest on the lathe. I like to make my bores in 2 halves on the router table and then epoxy the 2 halves together for an invisible seam. I then use my custom set of reamers to ceate the taper I desire. Any home machinist can make a set of these for you cheaply. There are also plans for reamers in Trevor Robinson's book "The Amateur Wind Instrument Maker". Here is a site page from the Recorder Homepage on Reamers...

http://www.recorderhomepage.net/tools.html#Reamers

Here is a Discovery Channel Video that shows a steady rest and reamer technique...
http://www.youtube.com/watch?v=WiSW6LPchSc

[Feadoggie]

Mark Hoza has offered just such a Quena for some years now.

[tyiam]

a professional instrument would require a tapered bore for acoustic superiority.

Fedoggie and Thomas... Your information / link was very right on... It sounds like a good direction to go. Yes, I am working in two different directions, one with a straight bore and a professional taper bore instrument. Much like Hoza and Rueda.

There are lots of Custom Reamer Companies out there... Has anyone ever had a Custom Reamer made or made one yourself ? Any suggestions ?

Thanks,
-Ty

[Feadoggie]

Has anyone ever had a Custom Reamer made or made one yourself ?

Never had one made to order. I've made my own, not well I might add. But it's not too hard if you have a machine lathe and a milling machine. I started out as Thomas suggested earlier by following what was written in Trevor Robinson's books (and others) and then from what I found on Nicholas Lander's Recorder Homepage. Gary Cook has a nice write-up on how to make recorders including making reamers and a broaching tool. Oh, I see that article was also linked by Thomas-Hastay, good stuff, great minds...! The back issues of Woodwind Quarterly were helpful to me when I was starting out. There are a lot of additional resources buried around the Internet if you take the time to search.

I have also looked through a couple tooling catalogs online for stock tapered reamers that would work for flute making and you can get pretty close to a proper flute bore going that route. That's just pricey for me as a hobbiest maker at this point.

Let us know how the Quena turns out!

Feadoggie

[brewerpaul]

Mark Hoza has offered just such a Quena for some years now.

Now what did you have to go and show me that for?

[Feadoggie]

Now what did you have to go and show me that for?

I thought others, like yourself, might want to see some inspiration.


And for those interested in Quena designs.

[Thomas-Hastay]

I'm a Journeyman Machinist with a degree in Mechanical Engineering. I have a few small Mills, but I make my own Reamers on a CNC Hobart milling machine. I suggest you head to your local High School Metal shop and see if you can con someone into making a couple reamers. You might also try a local Machinist Tech School and ask a student to make one for you. Of course, you'll have to pay them, but it won't break the bank. I personally have never found a commercial reamer with a long enough taper for making woodwinds. There are also some fancy Router Table jigs for making tapered half-bores. Do some Googleing...(?)

[JackCampin]

As far as I can see, there is nothing in the mathematics on that page about quena designs that addresses the flat second octave issue. They just say if you leave the end plug off you can get the first octave dead in tune. I think we already knew that.

[Thomas-Hastay]

Conical bores eliminate the flatness in the second octave by shifting/compressing all the antinodes in the second octave closer to the voicing, this also increases acoustic backpressure. This is the reason Recorders are well in tune in the second octave. Cylindrical bores suffer from flatness because the aircolumn extends farther out the bore end due to increased aircolumn velocity.

[highwood]

there is nothing in the mathematics on that page about quena designs that addresses the flat second octave issue

There might be...
For example: say one used/solved eq #3 instead of #5

onward... deeper down the rabbit hole...