New style whistle heads

[stringbed]

Quoting Terry, quoting me:

"I was doing the same thing with Moeck’s Rottenburgh recorders in Celle a few years earlier."

What prompted that, stringbed? I spent 7 months in England, Scotland and Ireland in 1974 to find out what was happening in folk music in those countries. … I wasn't aware of any whistle or Irish flute makers (if they even existed), but it was a great period for baroque instrument making.

I spent four months of 1968 on a similar pilgrimage to Europe directly focused on the making and playing of Baroque instruments. One of the ports of call was the historical instrument studio in the Moeck establishment, run by Otto Steinkopf. I had been playing his instruments for a few years and met him in NYC (where I’m from) in 1967. When told of my impending trip, he invited me to visit him in Celle if the itinerary could be steered in that direction.

Making a long story short, I made that visit and returned a year later after accepting a generous unexpected offer of a position there from Dr. Moeck, It was formally as an apprentice to Herr Steinkopf but on regular terms of employment. I had no intention of becoming involved with recorder manufacture. However, when plans were made for Friedrich von Huene (who I knew from the States and had made my go-to alto recorder and traverso) spending the summer of 1970 in Celle working on the production of his Rottenburgh instruments, I moved into that shop.

There was only one tuner and voicer there at the time and I was encouraged to expand that number, while continuing the broader apprenticeship. I was trained by the incumbant, who was the most experienced in the organization, and benefitted immeasurably further from working with Friedrich. A third voicer was taken on board shortly afterward and I became the one of us who dealt with custom tuning and voicing requests.

[Terry McGee]

Ah, great story, stringbed.

Isn't life funny. You start out with certain expectations - in my case it was landing a dream job designing and making support electronics for cutting edge physical science research - but suddenly you find yourself being dragged off in completely other directions. I'll admit I didn't put up much of a fight!

[stringbed]

For me the career trajectory went through the realm of musical instruments from the very outset. But, boy, did it ever do some twisting and turning.

[Terry McGee]

Yeah, even when I seriously embarked on instrument making, I had assumed I would do a mix of early and folk flutes. In fact, my byline on my web page still says: "Flutes for Irish, Classical and Early Music". Well, that wasn't the reality. Irish music won, hands down. I still remember attending a Comhaltas event in Dundalk in 1974, where the elders lamented "well, this is the end of the music as we have known it". Not quite, as it transpired...

[hans]

Interesting topic I just read now!
Coming back to the points about chamfer and block:
By making whistles from industrial alu tubing and using a curved windway and blade, and a block OD cut to the ID of the head tube, the air stream exiting the windway will hit the blade on the high side, if the blade is sloped traditionally, and not much will enter the bore underneath it. Therefore I assumed that a good chamfer on the block (the lower chamfer) is essential in order to unbalance the airstream and initiate oscillation. Likewise by letting the block protrude a little into the bore, further down than the windway roof exit, the whistle will respond quicker in producing a tone, especially for lower notes. For me that was/is an important design criteria. Without the block protrusion the whistle would not speak that easy. For a D whistle I mostly used up to 0.5mm protusion, for low D about 1mm. I did not care much about upper chamfer, just made sure everything is supper smooth, including the inside of the windway.

[Terry McGee]

And, Hans, what in your experience constitutes "a good chamfer" on a High D whistle? Say 1mm of chamfer, at around 45º? And left as the angle, or any smoothing of either or both of the transistions?

And what do you think the block protrusion actually does, in physical terms? I've seen it often as a regular feature of recorders, but can't bring to mind any explanations of what's actually going on there. Any thoughts?

Heh heh, coming to my mind is a totally adjustable whistle head, with dozens of little thumbscrews and wheels for stopper protrusion, windway width, windway height, window height, ramp angle, window length, etc, etc. You probably wouldn't be able to lift it unaided....

"Quick nurse, McGee is out of his bed again, and heading for the workshop...."

[hans]

And, Hans, what in your experience constitutes "a good chamfer" on a High D whistle? Say 1mm of chamfer, at around 45º? And left as the angle, or any smoothing of either or both of the transistions?

Ahh, I wrote "good chamfer" so I don't need to commit to particular measurements! I mainly followed the tradition I observed in the shape of various well-built whistles, and not using a lower chamfer did not help. For a high D whistle I like to set the window to 8mm width, and 4mm length (from labium to upper windway exit), with the block having about 3.5mm distance to the labium, so it protrudes 0.5mm. The chamfer filed on it would be between 45 and 60 degrees, say. I preferred it a bit steeper than 45, and not cut too much off at the windway floor. The cutoff should not be more than the protrusion, perhaps even a little less. I always smooth any edges. Perhaps a totally rounded chamfer may work as well, I don't know.

And what do you think the block protrusion actually does, in physical terms? I've seen it often as a regular feature of recorders, but can't bring to mind any explanations of what's actually going on there. Any thoughts?

I don't know, my acoustical physics is not good enough. I imagine it plays a role in unbalancing the air stream. I hoped you could tell me! Most makers use it, both for straight and for curved windway designs. Terry, for what I can read in this thread, you have not delved into the difference of straight versus curved windway and labium. I think there are acoustic differences, and to me a curved windway/labium will produce a somewhat rounder tone.

Heh heh, coming to my mind is a totally adjustable whistle head, with dozens of little thumbscrews and wheels for stopper protrusion, windway width, windway height, window height, ramp angle, window length, etc, etc. You probably wouldn't be able to lift it unaided....

And add to that windway curvature....
The problem with the "fully adjustable head" is that it cannot guarantee a fully smooth air stream, there are too many edges in such a machine, and that influences the tone.
And of course this also needs a blowing machine, where you can adjust and measure pressures and air volume and speed...

[Terry McGee]

And, Hans, what in your experience constitutes "a good chamfer" on a High D whistle? Say 1mm of chamfer, at around 45º? And left as the angle, or any smoothing of either or both of the transistions?

Ahh, I wrote "good chamfer" so I don't need to commit to particular measurements! I mainly followed the tradition I observed in the shape of various well-built whistles, and not using a lower chamfer did not help. For a high D whistle I like to set the window to 8mm width, and 4mm length (from labium to upper windway exit), with the block having about 3.5mm distance to the labium, so it protrudes 0.5mm. The chamfer filed on it would be between 45 and 60 degrees, say. I preferred it a bit steeper than 45, and not cut too much off at the windway floor. The cutoff should not be more than the protrusion, perhaps even a little less. I always smooth any edges. Perhaps a totally rounded chamfer may work as well, I don't know.

OK, that's good guidance, thanks.

And what do you think the block protrusion actually does, in physical terms? I've seen it often as a regular feature of recorders, but can't bring to mind any explanations of what's actually going on there. Any thoughts?

I don't know, my acoustical physics is not good enough. I imagine it plays a role in unbalancing the air stream. I hoped you could tell me! Most makers use it, both for straight and for curved windway designs.

Would this be a feasible enough explanation, Hans, others? Having the block protrude a little into the window area helps force the returning pressure wave upwards earlier, lifting the jet out of the window to start the next halfcycle?

And perhaps chamfering off the end of the block restores the full length of the window to the airjet, stopping the edge of the protruding block from impeding the airjet on its downward cycle? Giving the jet permission and room to go down, but not actually forcing it to go down? Anyway, perhaps we simple whittlers and carvers don't need to know the gory details, just have faith?

Terry, for what I can read in this thread, you have not delved into the difference of straight versus curved windway and labium. I think there are acoustic differences, and to me a curved windway/labium will produce a somewhat rounder tone.

Hmmm, you raise a good point there, Hans. And it applies also to the Comparison of High D whistle bores listing. The inclusion of (curved/straight) or (curved/flat?) would enable readers to say: "I like the robust sound of big-bore flat-blade whistles, what are my options in that area?" or "I prefer quieter, more economical sweet-sounding curved blade whistles, so what's available there?"

But I wonder if flat windway whistles have rather given way to curved, just because the curved ones are easier to make using round tube, unless perhaps when using the moulded plastic head approach?

[stringbed]

…what do you think the block protrusion actually does, in physical terms? I've seen it often as a regular feature of recorders, but can't bring to mind any explanations of what's actually going on there.

It’s been a long time since I’ve paid attention to trends in recorder making. If block protrusion is now a regular design feature, it became so in the meanwhile. Can you point me in the direction of a few examples?

…what…constitutes "a good chamfer" on a High D whistle? Say 1mm of chamfer, at around 45º? And left as the angle, or any smoothing of either or both of the transitions?

Again speaking from back in the day and with regard to recorders, chamfering is a core aspect of the voicing process. As such, it is adjusted by ear not measurement. It’s easy enough to set numbers on the block chamfer for a good first approximation. The upper chamfer (the one at the end of the roof of the windway and significantly smaller) is another matter. It is crucial to getting a recorder comfortably into the third octave but is tricky enough to see, much less measure. I’ve been party to many discussions about how to address the latter detail when documenting historical instruments. The way I understand it, the effect of chamfer benefits from clean faceting. I’ve read descriptions of it being added to assembled whistles by rubbing sandpaper across the end of the windway but have a rough time imagining that clear-cut chamfers would be less purposeful.

I wonder if flat windway whistles have rather given way to curved, just because the curved ones are easier to make using round tube, unless perhaps when using the moulded plastic head approach?

In historical practice, recorder windways were arched both axially (roof only) and radially — and tapered in width to boot. I regret not having examined how this mapped into flageolet design while I had access to an extensive collection of both instruments. The present discussion lies on the same continuum and I’m curious to see where it leads.

[hans]

But I wonder if flat windway whistles have rather given way to curved, just because the curved ones are easier to make using round tube, unless perhaps when using the moulded plastic head approach?

That may indeed an important reason, it certainly was a reason to start me into whistle making. But the historic traditional tin whistle had a flat windway, and a simple design too. So has the modern equivalent, the Overton. But it needs some good machinery to squash the round alu tube into a square shape for the head. But this then gives the advantage of bore restriction in the head, and thus helps the octave tuning!

In historical practice, recorder windways were arched both axially (roof only) and radially — and tapered to boot. I regret not having examined how this mapped into flageolet design while I had access to an extensive collection of both instruments.

I have been using a tapered windway for all my whistles, I reckoned that a slight taper would lead to a smoother air flow, with less resistance from the walls.

[Sirchronique]

it needs some good machinery to squash the round alu tube into a square shape for the head.

Didn’t Overton simply use a hammer?

I thought I recalled seeing a video where he clamped it from the sides and then hammered the top flat.

[Terry McGee]

It’s been a long time since I’ve paid attention to trends in recorder making. If block protrusion is now a regular design feature, it became so in the meanwhile. Can you point me in the direction of a few examples?

Hmmm, I think I'd bow to your greater experience in the field. I'm sure I've seen it, but that could well be in instruments brought in for repair or attention. I don't think we see much sign of protrusion in whistles either, do we? The windways on all the plastic ones I've seen definitely stop dead at the window. The most obvious block protrusion I can visualise is on the classic Clarke whistles. And there it is so obvious, the first time I saw one I assumed something had gone wrong in the making. Here's a reminder, taken from their website. Note, no noteworthy chamfer:

[stringbed]

The most obvious block protrusion I can visualise is on the classic Clarke whistles. And there it is so obvious, the first time I saw one I assumed something had gone wrong in the making. Here's a reminder, taken from their website. Note, no noteworthy chamfer:

I regard Shaw whistles as truer instantiations of Clarke’s putative initial innovation than the eponymous ones now are. I have three Shaw whistles at hand; high D, C, G in descending order. They were selected out of a batch at Waltons on George’s Street in Dublin fifteen years ago, when side-by-side testing was both permitted and encouraged. There’s no body chamfer on them, which I wouldn’t expect on any instrument rolled from thin sheet metal. The blocks have no chamfer either but their lower ends are cut on a bias, roughly paralleling the one that forms the beak but at a less acute angle to the axis of the bore.

The edge of the inner end of the block on the windway side underlaps the upper edge of the window. The edge of the block opposite the window protrudes into it by well over half of the window’s length. I have no idea if the position of the block or the bias of its inner end were deliberately adjusted during the tuning and voicing processes. However, changing overlap/underlap ought reasonably to have an effect similar to adjusting chamfer — and the angled inner end of the block can also be seen as a steep non-faceted chamfer.

ETA: I’m now taking closer looks at other whistles in my arsenal from the perspective of the present discussion. I note that Phil Hardy extends the block into the bore on many, if not all, of his models by the width of the chamfer or just slightly less. I picked up a range of Chieftains on the same visit to Waltons and will write more about this aspect of their design in comparison with his later models separately, after the iterative dig through the remaining whistle heap.

[Terry McGee]

Interesting stuff, stringbed. If I understand correctly, in some of these you are saying that the entire inner face of the block slopes, with the top (under the windway) starting before the end of the windway, but with the bottom of the block protruding significantly into the windway. An extreme and steep chamfer, if you will.

I've wondered about that approach, from the perspective of what happens to the returning pressure wave front as it approaches the back of the stopper. Just slams into it, and then looks around for a way out of here? "Hmmm, I'm going to have to shove that pesky air jet out of my way..."

What would happen if we gave it some help and guidance? A slope at the back of the block as I think you've described to redirect it upwards? Or would it be better to offer it a curved (concave) slope to coax it around the corner and help it redirect its energies into shoving airjets rather than generating heat? Or am I fantasising and anthropomorphising?

We could probably test these questions by sticking shaped block extensions into the back of flat-blocked heads.....

It's times like this I miss the late (Prof) Neville Fletcher. If asked, he would think for a moment and then say: "I'm reminded of some work a student of mine did up at the University of Armidale. We found that...."

And thinking, Tunborough, that we are now transgressing from acoustics into aerodynamics, so maybe the WID model can't help us here? Feel free to shoot me down in flames....

[david_h]

Heh heh, coming to my mind is a totally adjustable whistle head, with dozens of little thumbscrews and wheels for stopper protrusion, windway width, windway height, window height, ramp angle, window length, etc, etc. "

I have been holding my breath, and realise that it may be the wrong thing to say in the company of craftsmen and engineers, but would a 3D printer have roll here. It might not make finely tuned whistle heads but one change at a time would be possible. Results could be hooked up to the blowing machine.