I pondered this concept of an all metal conical flute myself and its something I've been mentally toying with, just to eventually do it some day if I ever find myself caught up with nothing else to do and am bored to tears. I want to try it just to teach myself some techniquery but it requires some major prototyping and tooling up for turning it into something I could perhaps regularly manufacture. I just don't have the time in my schedule though! Replacing some of the tools I use on a daily basis with new and better ones remains a better use of my tooling-up time! And my production time is best spent trying to get waiting orders out to my ever and increasingly patient clientele (see footnote).
Some thoughts of how it could be done: Making the mandrel for the bore is the easy part. That is just like making a reamer except you don't need to make a cutting edge Then there are the blocks of lead (ugh! Not something I want to handle on a regular basis! Or at all!) and the heavy hydraulic press required to squeeze the bodies through the lead to the right shape, such as what Michael Copeland does for his whistle bodies. Another possibility would be to use a softer or even annealed silver and using metal spinning techniques try to fit it to the mandrel. Or maybe a combination of the two techniques. Probably if/when I try it for the one time I'll start with sheet silver and bend it around a metal mandrel, wire it up, withdraw the metal mandrel and insert one made from charcoal, flux it and solder it, then spin it to size. The headjoint and socket/tenon parts could be simply made from tubing.
Another way to try this would be to find telescoping tubing and make a flute in a similar fashion to David Daye's "Penny Chanter". But that would be heavy and ugly and miss the whole point of this! Its too bad that the K&S tubing stops at 21/32nds.
In the old version discussed they put risers for the embouchure and the fingerholes to duplicate wall thickness. However, a simple flute could be made with simple fingerholes like on a whistle and the embouchure with a raised cast chimney and lip plate such as is done on a modern flute. The flute could be made in a simple 2 piece configuration. In a well drawn hard thin walled silver this could theoretically be a very nice instrument, and if well voiced, very responsive. Good for any climate as there would be no chance of it cracking ever. You could even pour your Guinness through it! Dishwasher Safe. And like the modern flute it could be done up in other precious alloys such as Rose Gold, Platinum, etc. And richly engraved like what they do with saxophones, adding much to the playing qualities of the instrument. Or so someone would eventually claim when these eventually take off as the Next Best Thing since Buttered Toast!
A number of things to overcome though. It is nice to have wall thickness for voicing the fingerholes and balancing the octaves by undercutting and this would be impossible without adding the fingerhole risers such as on that original. Without, the flute could be somewhat squirrely to grip. Keys could be easily soldered on but then compound the finger ergonomics. One could add the much maligned Boehm Crutch (I did this to my old Artley in 9th grade, using a Lyre post from a clarinet).
The thing I find interesting is this fascination with such concepts as this (as well as plastic flutes in Delrin) as if this represents an improvement and the eventual evolution of the instrument for the better. They tried this with other instruments such as Clarinets (search for metal clarinet on eBay and you will see several that would make a good lamp), Guitars (think of the plastic backed dull sounding Overtons) and Violins (Stroh fiddles) whereas the best practice remains wood-based, even if the wooden ones require a few seconds attention to proper care in our otherwise throw-away society. People should not fear wood, even if things occasionally split.
My conclusion is that these concepts, while interesting, are a distraction and are anything but the further development. Just a side branch. The Irish Flute in wood is a vestige of a main branch, having been revived in the past century as Irish music underwent a resurgence. In the flute universe the Irish Flute is the Walking Dead. There are several interesting and already tried abandoned flute design paths, well documented in histories of the flute such as "The Flute" by Philip Bate, still the best flute history written and much easier to read than some more recently written tomes, some of which are so dense they warp gravity. Some of these designs are very intriguing and lovely such as the crystal flutes of Laurent, Georgi Flutes, Burghley's Alto Flute experiments and the Albisphon.
There is one variation worth someone trying someday and that would be making a conical bored metal Boehm flute. It would have all the modern flute ergonomics and key systems but with a good bore the lovely sound of our Rudalls and Prattens. The modern flute with its cylindrical bore is still really a fife and weak in the overtones. Wooden headjoints only go a small way to getting the reedy sounds we get out of our conical bored flutes. Its the shape of the bore, not the material the flute is made from!
An aside. This topic reminds me of some of my less brilliant decisions made earlier in my flute making career. I was easily distracted. Usually what happened was someone wanted to try some novel idea, and have their flute maker make this or some other monstrosity for them and make their fantasies come true, such as weird key systems inspired by Radcliffe or whatever if one confines it to just flutes. In my earlier days I was an easy mark for such activities and I spent many hours prototyping such things to little or no advancement of my career or progress to my queue, not to mention the eventual major crisis when the rent and other bills came due - surprisingly when these were supposed to be. Always, the client wanted to only pay for the "retail priced" product once it was done - as if these things were now fully figured out and in full production. Never anything for the head scratching, technique learning curves, tooling up, materials wasted, and failed attempts and setbacks. Or paying for the final effort if it was less than perfect, however defined by their fantasies.
Eventually I knew better. Perhaps the only benefit to my career from these activities was learning that these interesting concepts were far from the mainstream and that conservatively sticking to the mainstream was much, much better for my survival! Now when someone wants me to try the untried I have to weigh opportunity costs and the advancement of my career and keeping my current clients happy Vs. prototyping costs and materials, all billable to the client up front and this client is usually aghast at the 5 or 6 figure price that gets quoted. Now I don't even bother to calculate, I just start the bidding at $250K, which effectively ends this usually. I've had a few try to even convince me that these grandiose ideas will really take off some day and that I am missing out on some huge opportunity by becoming the inventor of something that will eventually rival the Pianoforte and render it to obscurity and that all of these prototyping costs etc. I should cover myself. If they think it is such a great idea, they should try it out themselves!
(Footnote - a few of you know I've been fighting some strange health symptoms for the past few years. These have been hell on my scheduled promises! After testing for about everything else, recent lab tests just confirmed that I'm suffering from tick borne Lyme Disease. Caught here in Washington State. I call it the Borrelian Plague, as if it was something you could catch in a Star Trek episode. Its an emerging disease found nearly everywhere, not just New England - learn about it, especially if you or your loved ones are suffering from any unexplained chronic symptoms. See
www.lymenet.org and become educated.)
