This is aimed at the whistlesmiths out there in chiff’n’fippleland, what are the pros and cons of curved blades or straight blades, or is there no actual difference?
it has to be said I have never made or played a curved blade.
Cheers Richard.
I have done both now. The newest whistle that I’ve built has a curved blade and a matching curved windway. I can’t tell a lot of difference in tone, but there is a pronounced difference in volume.
This whistle is also using a delrin fipple plug instead of wood so that may be contributing to the volume increase as well… I’m not sure.
A question posed to Monica Lewinski.
Did I win!
MarkB
It may be mostly a question of manufacturing more than colour of the sound.
My two-megs :
Curved blade may make manufacturing easier, especially on a lathe.
The plug-in-tube-in-sleeve design of round windway (Sindt, Grinter come to my mind) is easy to manufacture.
The tube-hammered-square (Overton) may have the advantage of reducing the initial surface of the bore (just after the blade).
And I personnally tend to find a curved mouthpiece more comfy, but I never “chew” on it as some do…
On 2003-02-20 09:43, Zubivka wrote:
It may be mostly a question of manufacturing more than colour of the sound.My two-megs :
Curved blade may make manufacturing easier, especially on a lathe.
The plug-in-tube-in-sleeve design of round windway (Sindt, Grinter come to my mind) is easy to manufacture.
The tube-hammered-square (Overton) may have the advantage of reducing the initial surface of the bore (just after the blade).And I personnally tend to find a curved mouthpiece more comfy, but I never “chew” on it as some do…
Ah zoobie-pie you’ve seen the reasoning behind the question, its easier to make the revesed taper as a cone, which would give a curved blade, but if curved blades were not as good, then I’d have to go a pyramidal (?) revesed taper blending into the tube at the 1st joint giving a flat blade but harder to make.
Richard.
Well, the blade has to match the windway for the whistle to work. A curved windway is thought to be less prone to clogging by some of the makers. Which is easier to make depends on the method of manufacture. Plastic could be molded either way just as easily, and a quick survey of my plastic mouthpieces shows that all have straight windways and blades, including Waltons, Sweetone, Meg and Dixon.
Richard;
I understand it’s wood you’re after, hence mostly lathed so I’d go rounded windway.
If you were an whistlesmith in the litteral sense then there’s a lot to say for the tube hammered square.
Anyway, there’s nothing wrong to fear about rounded windways. There’s nothing principially wrong with them as prove so many with so differently coloured sounds: To Grinter, Sindt, I could have added Susato (probably the initiator of the modern curved wide blade) and not forgotten Copeland, even if this is more a smithed than machined whistle. This are only a few, but none known as failures, right ?
Come to think of it, flat blades seem to be getting a near-exception in the high end. They’re either inspired by the original “recorder” design (narrow blade filed flat) or the very original full-width of a square Overton design.
All the powerful whistles seem to have but one thing in common : an extremely wide (if short lengthwise) blade, up to almost 1/4 of the circumference of the tube at this level.
To me it’s the most obvious departure, beside bore, from the traditional recorder.
So you got a free choice, mate : the roccoco pansywood design of the ancestor, or our modern industrial “heavy-metal” whistle with its postmodern avatar the cocobolo “hot-lips” whistle.
Just tell us what side you chose 
I think that very often it may be a function of the whistle makers tooling and production requirements. Whistles made from preformed tube with a flat blade can be manufactured with a press and a minimal number of operations, whereas making a curved airway involves use of a lathe and precision machining on more separate individual parts per whistle. With the flat blade, the precision machining is most necessary on the original dye from which many whistles are made, hence considerably cheaper production.
Mine have curved windway and fipple. This is largely due to the way these whistles are made-- first I make a wooden tube, and work from that. Due to the nature of the head joint, the surfaces in question come out curved. The bottom of the blade is simply the inside of the tube, the top of the fipple matches that, etc.
From what I’ve read on whistle type sound producing heads, a curved windway has an advantage due to the physics of airflow. Unless you make a square whistle ( why not?), it’s better to have a curved sheet of air impacting a curved blade as these parallel the round cross section of the whistle. With a flat windway, there are apparently inefficiencies in the laminar air flow ( gee, it almost sounds like I know what I’m talking about…).
The reasoning is so I can integrate a Boehm revesed taper into the whistle, As the wood for my low d is now resting, I bit the bullet last night and introduced a reversed taper into a copper whistle, cut/shut and solder to give me a 1/10 reduction in tube diameter tapered over 1/6 of the total length of the whistle from the blade.
And soooo ?
What’s the result ?
err… it works!! 
I’ve got to agree with Zubivka, Bodrans and Brewerpaul. Its really a matter of the easiest way to make the fipple. I’m using a flat airway and blade on my Low whistles (in wood) and a curved airway and blade on the high whistles (Delrin). Its really not the shape of the airway that is the main concern here, but the fact that the airway is a metering duct that allows for a precise amount of air to pass thru. I have found that I prefer a fairly focused vertical distance of the airway to give a specific back pressure, which brings out the overtones, and then adjust the width to balance the upper and lower octaves and adjust the total volume of the instrument.
If you are working in wood, then there is another factor (if you are using a flat blade) and that is the transition from the blade to the cylindrical bore of the body. This undercut (which puts drag and resistance on the airflow) affects the tonal quality of the instrument. Of course if you are bending metal then the dynamic of the airflow is something very different and so is the tone.
There are a lot of ways to skin this cat and thats why there are soooo many different sounds in whistles.
Ronaldo
[ This Message was edited by: reyburnwhistles on 2003-02-21 17:30 ]
On 2003-02-20 10:24, jim_mc wrote:
Well, the blade has to match the windway for the whistle to work.
Not so…I have converted my Susato to have flat blade instead of curved.Not only does it work with a non-matching curved windway,it sounds great as well.
Mike
Well, (ya I know… deep subject ) I use an odd combo that I think sounds quite nice… the airway on mine consists of a plug with a flat, that is machined and sanded, and is inside a round fitting. Sort of looks like (| (on it’s side)
The blade however, is simply an angle sanded into the tube that the mouthpiece slides onto, so in effect there is a half-flat, curved blade combo that works rather well in my opinion. The blade ends up being curved “with the tubing” but also curved “away from the mouthpiece”. try cutting or sanding an angle into the end of a piece of tubing, and you’ll see what I mean.
It may be more temperamental to get it just right or something, but I don’t think so. Also it allows the nifty adjustable volume principle.
Adjusting the volume however, creates a difference in chiff.. the more normal or quiter you go, the more easy-solid the sound is. The louder or more ‘open’ you go, the more chiff you get… If you have good lungs though, you can get it to be more solid if you have it opened up!! I’m used to playing it louder to get through a large session w/ many instruments, and playing with the local Celtic Society’s Bag Piper!
Take care,
John
EDITED for children, small animals, and general information that is still somewhat weird to try and explain.
[ This Message was edited by: McHaffie on 2003-02-22 11:30 ]
I can’t say why, but all the whistles I tend to really enjoy playing seem to have a curved windway and blade. So far. But I don’t mind being tempted by something different!
Serpent whistles, with the sole exception of the Village Smithy, have a D-shaped airway and a curved blade. The combination gives a bit of airy chiff to the sound in the upper register, but is easier to manufacture and tweak without distorting the tube. (The VS has a squared head with a flat airway and blade.) The radius of curvature of the blade is the same as the ID of the respective tube, and the base angle is set at 9 degrees, with the edge being ground to around 45 degrees, with a slightly rounded profile. The edge is set at 0.060" below the inner surface of the tube, and the fipple is set at 0.080" to same (high whistles). The use of the brass fipple plug, machined and polished on top, obviates some of the condensation problems found in wooden and synthetic plugs, so, as Jim Peeples observes, simply warming in the hand prior to play will prevent most clogging. The solid brass plug also presents a significant thermal mass, so maintains heat longer when not being played, than wood or synthetics.
I have experimented with curved fipple plugs, and have not found anything to overwhelmingly recommend them over the D airway, so, since they are at least four times more difficult to make than flat-toppers, have abandoned them as an option. Any extra time spent on them would have to be passed on to the consumer as extra cost, and I don’t think the (questionable) advantages warrant that.
Just my 2p
serpent
[ This Message was edited by: serpent on 2003-02-23 15:48 ]
Brewerpaul and Reyburn I can understand quite well, but McHaffie and Serpent, sorry, this is a case where a picture is worth a thousand words. Just can’t get my brain organised enough to form a picture of what you are saying.