Comparison of High D Whistle Bores

[Terry McGee]

Regarding bore profiles of whistles, a lot of whistles employ some kind of head taper which I think of as being analogous to the
parabolic head profile of a Boehm flute. Sometimes this takes the form of plug extensions that protrude into the bore either
side of the window. In other designs the external profile of the head may be compressed into a squared-off profile that also
impacts the bore volume in the head area. I'm not sure if you want to add notes on this kind of thing, but it is probably just
as relevant as the specific bore profile of conical bore whistles.

That's tricky isn't it. It requires a consideration of whether the cross sectional area of the bore is being significantly diminished over a significant enough length of bore. A lot of value judgments to be made there.

For the conical bore whistles, you would need to specify where on the bore the diameter is measured, if you are going to use just
a single value. Some of the measurements above seem to be using a measurement at the foot. However, I think the more acoustically
relevant measurement would be at the head, close to the window. I think that contributes more to determining whether a particular
whistle performs like a narrow or wide bore cylindrical model.

You can't just use a single value, can you? You'd really need to specify the diameters at top and bottom of the taper, and the distance between them, plus the diameter of any untapered section, such as perhaps above the tuning slide.

If we look at our only tapered whistle data point, it currently tells us:
P.G. Bleazey High D in Mopane, tunable (0.37", 9.3mm at foot; 0.50", 12.8mm at middle joint)
Ideally, for the sake of comparisons, we'd need to know where the head bore meets the tapering section, and the diameter(s) and slope(s) above and below it.

And adding the suggested figure for speaking length, we'd end up with something like:
P.G. Bleazey High D in Mopane, tunable (0.50", 12.8mm x length from blade to the end of the cylindrical section; 0.37", 9.3mm x length from there to foot)

This raises a question. In flutes, the narrow part of the tuning slide always protrudes from the head, entering into the wider section in the barrel. Do whistles follow the same convention, the opposite convention (possibly arguing that, hey, we're tapering downwards here, lets make the slide transition part of the taper), or do they vary? I suspect I've seen both. IE, in some cases, the thinner slide poking out of the head, in other cases, the thinner slide poking out of the body. Whatever, anyone providing us with data on a tapered whistle with tuning slide needs to be alert to where the junction between cylinder and taper lies.

Regardless of the level of detail, I think a resource like this would be valuable.

OK. Let's plug on! (As we say in the stopper insertion industry). Hmmm, on that note, can D.I.Y. whistle makers be rightly accused of self-flageolation?

[Tunborough]

would you:
1. Say that it remains useful for our growing table of bores to include the points from his graph as meaningful markers? EG [Bracker thinnest]
2. Agree that it's appropriate to use Bracker's name, or can you suggest something more appropriate?
3. Suggest a less clutzy collection of terms than the ones I've come up with? [Bracker central zone fat end] - Sheesh!

I'm fine with using Hans's name to mark the ranges on his graph, and I do think those markers are very useful. I wouldn't attach too much significance to the bounds of the central zone, so I'd suggest limiting the markers to [Bracker very narrow], [Bracker mid-range], and [Bracker very wide].

We could use the formula behind that graph to rank whistles of different keys. I'm thinking of a bore size index, where 1.0 is the mid-point for bores of that key, 0.8 is 20% smaller than the mid-point, and 1.2 is 20% larger than the mid-point.

Oh dear, Tunborough. You certainly know how to read minds and press buttons all at the same time. The promise of solid bottom notes with sweet, agile top notes. And possibly tighter tuning? OK, let's cut to the chase. How much chocolate (whiskey, whatever) would we have to send to get you to do even a quick look at that?

If you could send me a couple of extra hours in the day, or an extra day in the week, that would help a lot. Fortunately, the holidays are coming, and I'll be taking a week off. I happen to have a Clarke D at hand that I could measure up. I'll let you know how it goes.

[intheair]

Reyburn D (10.9mm)

This is probably for a narrow bore model. My Reyburn high D has about 12.3 mm ID .

[Terry McGee]

I'm fine with using Hans's name to mark the ranges on his graph, and I do think those markers are very useful. I wouldn't attach too much significance to the bounds of the central zone, so I'd suggest limiting the markers to [Bracker very narrow], [Bracker mid-range], and [Bracker very wide].

OK, it's a plan. Thanks.

We could use the formula behind that graph to rank whistles of different keys. I'm thinking of a bore size index, where 1.0 is the mid-point for bores of that key, 0.8 is 20% smaller than the mid-point, and 1.2 is 20% larger than the mid-point.

I guess when we finally end up with a really good comparison chart for High D whistles, it's time to look at the others.

If you could send me a couple of extra hours in the day, or an extra day in the week, that would help a lot. Fortunately, the holidays are coming, and I'll be taking a week off. I happen to have a Clarke D at hand that I could measure up. I'll let you know how it goes.

Brilliant! That heavy breathing you can now hear is me looking over your shoulder....

And, "holidays"? I looked up the term in the McGee-Flutes Handy Lexicon of Technical Terms, but found nothing. Oh well....

It would be great to have the basic Clarke D dimensions whenever you can to keep company with the only other tapered whistle we have data for. I guess the only way to estimate the bore diameter at the fat end is to take the OD and subtract twice the Wall Thickness (0.3mm if I remember correctly from that video)? Or fill it up with whiskey, pour into measuring cylinder, take the measurement and then drink the evidence?

[kkrell]

I wish when I left my old Quality Control job that I had taken the gage pins set. Would be perfect for estimating bore ID. I suppose one could spin some Delrin rod (rather than stabilized steel) on the lathe, measure their OD & use as a rough substitute. Basically, a sort of feeler gauge, just round, not flat. Abrasion is eventually an issue, but not for awhile.

[Terry McGee]

Ah yes, but the complicating factor with the Clarke's, and I guess any other tapered whistle without a tuning slide, is access to the area inside the window. The foot is very constricted, so you can't come in that way. And you can't come in from the front end, or via the window. I guess you could pull/cut it apart, measure it and calculate from there. Not likely to win favour from the owner....

I think taking the OD and subtracting twice the wall thickness is our best bet. But I'm prepared to blow a bottle of Jamo's on the other method I suggested. Just to be sure, for the sake of science, you'll understand. Cue the out-of-tune singing...

[David Cooper]

Silicone rubber can be used to duplicate the bore of an instrument. Cover the holes, fill it up with the mixed solution (it comes in two bottles), then shove a smooth rod down the middle and leave it all to set. The next day, pull the rod out, then put a much narrower rod with a sharpish but rounded end between the silicone rubber and instrument wall to push the rubber into the space vacated by the original rod, and rotate this narrower rod to move it round the whole edge. Squirt silicone spray into the opened up space and let gravity work it further down as you keep working away by rotating the narrow rod and pushing it further in. Get hold of the end of the rubber and pull - you can do the rest of the job primarily by pulling it in slightly different directions. The silicone rubber can stretch to twice its normal length, going narrower in the process, so you can get it out through tight spots, then it rebounds to the correct shape afterwards. Once it's free, shove the original rod back into it and you have a good solid mould for making duplicate whistles - all you need do is rotate them 5-6 times a minute with a motor and apply craft resin in layers, gradually building the new instrument out of that food-safe epoxy over the course of several days - it becomes a very solid and rigid plastic - my craft resin quenas can double up as martial arts weapons. This will handle everything except the windway which may be too narrow - best to block that with blu-tack at the window end first, and then make your mouthpiece separately out of delrin. (Food-safe Craft Resin is safe for eating food off, but they don't recommend sticking it in your mouth - I don't trust the science on that as some foods could leach chemicals out it just as easily as saliva, but it's best to play it safe and consider "food safe" as being restricted to dry foods.) Alternatively, just measure the mould and devise your own way of manufacturing instruments with the same dimensions.

[Terry McGee]

Wow, David, that really is an extraordinary process. I would have thought you'd need release agents to make sure the stuff doesn't stick permanently to the inside of the item. But I guess the stuff you are using is not the same as the silicone glue used say to join huge sheets of window glass together in shops?

And I guess for measurement purposes you'd have to guard against measuring it while it's stretched or compacted. But a check of the length would be enough to confirm that.

[David Cooper]

You can get silicone rubber cooking utensils which are easy to clean as nothing sticks to them well (superglue does a bit, but you can still break it off easily), and that's the same stuff, but it would always be wise to test some in the end of the bore first just to make sure it comes off easily - you can never be sure what kind of chemicals might have been used in the bore that could potentially react in some unpredictable way, perhaps by stopping the solution setting and leaving a sticky gunge over the entire internal surface. It could be risky with old wooden flutes too as it might pull chunks out of the bore. Anyone attempting it should experiment with cheap, wide instruments first to learn the technique.

There are different grades of silicone rubber which vary in how elastic they are, so some are too rigid for this task. I've done my experiments with a brand called "Startso World" which is both good and inexpensive, so I recommend that one. The rod down the middle is important as it makes a huge difference to ease of extraction by keeping the silicone rubber thinner (more flexible) and providing space for it to move into when you prise parts of it off the bore after removing the rod. Even though silicone rubber doesn't stick to the rod, the friction is huge and you likely won't be able to pull the rod out, so here's the missing information needed to complete the technique: the trick is to coat the rod in a layer of plastic film that can slide off it and remain in the silicone rubber - I've used a one inch ribbon of plastic film wrapped round the rod in a helix and held together here and there with little bits of Sellotape.

[Terry McGee]

Wow, thanks for the additional advice there, David.

I've said before that there are at least two approaches to making flutes:
- the traditional boring out and turning down solid material. Excavators.
- the bringing together of lots of separate bits, as for the modern Boehm flute. Fabricators.
- and, of course we now have the 3D Printers.

So what would we term the approach of building up a solid body over a form? Applicators?

And what other approaches might I be overlooking?

[David Cooper]

Maybe it can be thought of as 3D painting (with resin).

[Terry McGee]

Basting?

[Tunborough]

Some additional data points, all high D whistles:

Jerry Freeman Mellow Dog, 13.56 mm (This uses a newer Feadog head, doesn't it?)
Feadog Mark 1, 12.0 mm (You have Feadog at 12.0 mm, but don't note it specifically as Mark 1)
Jerry Freeman Blackbird, 12.0 mm
Tony Dixon (not sure what model), 12.0 mm

[Tunborough]

There are challenges measuring the Clarke. The bore is mostly round at the bottom and up as high as the bottom of the Clarke logo, but around the window it is almost rectangular. For the top end, I picked the diameter at which a round bore would have the same cross-sectional area as the bore at the window, which is pretty much the cross-sectional area of the fipple. This gives the following data points for I.D.:

At the sounding blade: 15.3 mm
51.5 mm down (bottom of logo): 14.9 mm
88 mm down (between the gold lines): 13.8 mm
265 mm down (bottom of bore): 9.2 mm

[Terry McGee]

Heh heh, I thought it might get a bit ugly at the top of the Clarke body. And I had the same thought in mind, measure the rectangular bit as a rectangle, calculate the CSA and then express it as a Equivalent Bore Diameter. So that should be a useful technique with other "formed" head whistles.

Now, when you graph those results, you find that the lowest 3 numbers form a pretty straight taper, but the top number ("at the sounding blade") to the second number is almost cylindrical, just a reduction in bore diameter of 0.4mm. To continue the taper, the top number would have to be about 16.3, not 15.3. Interesting.

And if we average the four measurements, we get 13.3mm, which puts it just a bit above Bracker's centre of 13, and well within his upper limit recommendation of 14.5mm. Not far off Walton's Mellow D at 13.5mm. So, we might surmise it would have a warm, strong tone on that basis, say compared to the thin tone of the less than 12mm whistles like Feadog, Killarney etc. Is that your perception of the whistle, or do you think other factors such as the thin edge mess with that in practice? And do you think that averaging the bore dimensions is a reasonable approximation to cylindrical whistles, or does a better approach appeal to you?

Sigh, I only just got the joke about Walton's Mellow D. Mellow D - Melody, get it? You have to say it out loud....

The Canberra School of Music Library used to have a librarian whose name was Melody. Nominative Determinism at work? I wonder if she had a sister called Harmony? There there would be the twins, Melisma and Polyphony. And their brother Cacophony?

Merry Christmas all!