I’ve seen blade sharpness all over the map. Sharp, rounded, square-edged - pretty much the gamut. Various thicknesses, too. Can we hear from someone on advantages/disadvantages of the different profiles?
Thanks,
Bill Whedon
(edit 1 to change subject)
[ This Message was edited by: serpent on 2002-10-29 19:53 ]
I dunno nothin’ about whistle construction, but from info about tweaks (on Gen type whistles), I’ve read that if it slips into the second octave too easily, then dulling the blade may help. However, if you dull it too much, then the second octave gets breathy-sounding. My tweaking experiments (and disasters) have verified this.
Another observation… Someone mentioned in one of the threads that the regular Susato SB has a dull blade and that the VSB has a sharp blade. Maybe this accounts for the fact that first to second octave transitions are much cleaner with the VSB than with the SB.
Tried yesterday to play a big laughing whistle, made in England under 
Acme brand. Nice low whistle sound with half the length, pretty pure.
The funny thing about it is the blade : more than dull, it looks like there’s no blade. Just the tube, rather thick-walled, cut (rather, molded) straight in front of the windway.
However, I purchased another laughing whistle (Alto Ab…), clear+yellow+purple plastic for my 6-year old Sacha, he’s having fun. The translucent tube makes the whistle look strangely like a veterinarian’s syringe. The fipple is like a Generation, with a sharp blade, except it’s made of a supple plastic. Sound is nice, a bit more chiffy.
Note both whistles are in tune 
Is this the start of LafWhOA ?
–BbZH
On 2002-10-25 23:20, serpent wrote:
I’ve seen blade sharpness all over the map. Sharp, rounded, square-edged - pretty much the gamut. Various thicknesses, too. Can we hear from someone on advantages/disadvantages of the different profiles?
Thanks,
Bill Whedon
Saw tooth profile would be interesting..as a disadvantage example.Seriously though Bill, I think a slight dulling of the blade offers tonal advantages.Somone once pointed out the tip of the nose of the Concord is actualy rounded and not pointed for better aerodynamics.Flute and fifes also benefit from a slightly radiused embouchure I,ve been told. Mike
[ This Message was edited by: mike.r on 2002-10-26 06:46 ]
My blades are a bit shy of razor sharp. On a wooden whistle this has the major advantage of keeping the blade stronger. If you thin it down to only a coupla wood fibres thick, the edge of the blade can warp and/or split as it resides in the high velocity , high moisture airstream. On some grainier woods, I coat the finished blade with a wood stabilizer, or even water thin cyanoacrylate glue to strengthen it. So far, none have come back for repairs.
Just had a thought-- I have 2 whistles which I will be voicing pretty soon ( purpleheart and pau rosa). As I do this ( files, diamond files, 400 grit sandpaper) I will test play them at various stages of blade sharpness, and make notes to share here.
On 2002-10-26 07:46, brewerpaul wrote:
Just had a thought-- I have 2 whistles which I will be voicing pretty soon ( purpleheart and pau rosa). As I do this ( files, diamond files, 400 grit sandpaper) I will test play them at various stages of blade sharpness, and make notes to share here.
WoooHooo! Thanks, Paul! I’ll look forward to those notes!
As an aside - I’ve been keeping my blades less than razor-sharp, even tho using steel and copper (now brass, too), which are pretty much unaffected by the in-play moisture effects. Tried razor-sharp blades and they seem subtly less-easy to voice properly. Mike’s observation about the Concorde is a good one. Same deal with bullets, most of which (hunting rounds) use a secant ogive as a nose shape for maximum velocity and stability in flight.
There, also, is a place we can pick up some ideas for the discussion on windways and turbulence!
Cheers,
Bill Whedon
On 2002-10-26 06:41, mike.r wrote:
Flute and fifes also benefit from a slightly radiused embouchure I,ve been told. Mike
Well Mike, I suppose it depends what you mean by “Slightly Radiused”, I mean you’re not going to cut yourself on a good flute or fife embouchure edge, but the fact is, the edge you blow on does need to be fairly sharp to give the best sound and response - only the back and (sometimes) the sides of the embouchure hole will get (noticabley) radiused, depending on the shape of the hole and the maker:
The blowing edge of the oval shaped embouchure hole on my Olwell is VERY sligtly Radiused, however most would call it sharp, I think. The Healy Flute I owned, which had a somewhat rectangular embouchure hole, had a blowing edge that you could almost cut yourself on, as does the Seery Polymer Flute I’m borrowing at the moment, which has a more Oval shape.
Loren
P.S. I suppose there will be a number of people who say: “Yeah but, I filed down the sharp edge of my (fill in the blank with cheap whistle name of your choice) and it sounded much better”
I’d suggest that the reason for this is that you actually smoothed out (as well as dulled) a ragged edge blade, which may or may not have actually been sharp to begin with. A ragged edge (sharp or dull) I should think is going to have a negative impact in the efforts to produce an instrument with good tone.
Loren
As a curious note to not only the sharpness, but the leading edge of the blade itself.
Aircraft manufacturers slant the wings of fast flying aircraft to improve stabitily at high speeds. Would it stand to reason then, that an angled blade might somehow improve the tone/overtone/playability of a whistle? I’m talking about the whole leading edge, not the sharpness, but the overall shape.
So if you look from the top down, onto a regular windo and blade, youi see a rectangular opening. I’m suggesting a blade shaped like a triangle, or wedge (possibly reversed too??) instead of the flat edge…
Thoughts???
Bri~
Are we forgetting that speeding bullets, Concordes and jet fighter wings travel at way higher Mach numbers than the relative movement of air and blade in a fipple? Nice ideas, but I just don’t think they apply here.
I was thinking the same thing: Airflow reacts very differently at supersonic speeds when compared with the speeds we’re talking about.
Once again we need a PhD., this time in aerodynamics, or…a highly experienced maker of fine bladed woodwinds to accurately answer our questions.
But then those folks don’t seem to be hanging around and contributing to these threads, do they? Okay maybe some are hanging around, so in the meantime, Paul’s pending experiment not withstanding, we’re back to the blind leading the blind via speculation. Not very scientific, or particularly enlightening…
Loren
Loren, it could also be the the highly experienced makers of fine bladed instruments are just that - experienced. Now this is a good thing, except my guess is that most of them build their whistles based on what has worked before, not based on any fancy-schmancy scientific theory.
Fact is that the American Acoustical Society (of which I am not a member) still accepts papers on edgetone theory. The scientific details here are still being worked out.
In the end, these H.E.M.O.F.B.M.I.s probably are only passingly interested in discussions like this, because it probably doesn’t result in them selling any more whistles. Or maybe I’m just being cynical.
makers of fine bladed instruments are just that - experienced…most of them build their whistles based on what has worked before, not based on any fancy-schmancy scientific theory.
I would completly agree with this as many of the makers seem to have experimented and built up a knowledge of what works. (Didn’t Fred Rose spend a decade doing this?)
I was lucky to see Jim Copeland tweak my whistle with a file utilising a rudimentary jig. I asked how he knew when to stop - no specific answer, he just knew when it felt right!
I think that the old adage, “practice makes perfect”, applies here.
BTW what is/are H.E.M.O.F.B.M.I.s ?
Highly experienced makers of fine bladed musical instruments.
(a reference to Loren’s post)
Dave
[ This Message was edited by: dkehoe on 2002-10-26 14:59 ]
On 2002-10-26 13:10, Loren wrote:
I was thinking the same thing: Airflow reacts very differently at supersonic speeds when compared with the speeds we’re talking about.Once again we need a PhD., this time in aerodynamics, or…a highly experienced maker of fine bladed woodwinds to accurately answer our questions.
But then those folks don’t seem to be hanging around and contributing to these threads, do they? Okay maybe some are hanging around, so in the meantime, Paul’s pending experiment not withstanding, we’re back to the blind leading the blind via speculation. Not very scientific, or particularly enlightening…
Loren
You know,I had to laugh at the scientific test to validate the vibration of a specially designed flute.My daughter would simply touch it and feel that it vibrates.The human ear is far more sophisticated then man made devices, and most of us are more than qualified to contribute, because we are musicians..science has little to do with it. Mike
Oh, c’mon Mike, cut Loren some slack. I’m sure he didn’t mean to say that you have to be a scientist to contribute. I for one am a firm believer in the idea that everyone can contribute in some way, no matter their background.
With all deference to your daughter, sure she can feel vibrations, but it is Coltman’s (the concrete flute guy) contention that the average ear could NOT tell the difference. I’ll attach a link to an article you might find interesting.
http://www.tallgrasswinds.com/unsound.html
Dave
Don’t beat on each other, please. Loren suggests that scientific method is a Good Thing, perhaps a bit more than I personally believe, but hey, it sure doesn’t hurt to know what the heck some of this stuff we’re discussing, really means WRT whistle and flute building.
Honestly, had I waited until I completely understood what I’ll call “whistle theory” before building one, I’d’ve had a lot less fun of discovery, a little less pain of failure, and a couple hundred people wouldn’t own a whistle I made. As it stands, I still have my Very First low whistle, and in the light of my new ones, it sounds positively abominable - but I learnt several good lessons from it, so I consider it a success!
Back to the discussion: Today, I’m building a blade-setting die that’ll work on all my 9/16" and smaller OD heads. That will allow me to get identical sets on all blades, so I can then mill the edges in a special jig. Like Paul, I will run a series of tests to determine the (to me) “best” sort of edge profile, and if the difference is pronounced, will probably sacrifice a head by sawing it in half longitudinally, so we can see what the final result was with some exactitude.
Cheers 
Bill Whedon
Sharp blade/blunt blade. The position of the windway duct has its impact on this. In some cases if the blade is too sharp it (the blade itself) will develop a whistle sound other than the note your playing.
For example, the bullroarer (sp?), a sharp blade tied to a string. When spun around quickly, it makes a certain pitch. I’ve noticed it on toneholes when the come of the drill press and haven’t been deburred yet, the sharp edges protruded in the bore will whistle. Overly sharp edges can also whistle undesirable notes.
I’ve seen this mostly in metal whistles, not so much with wood.
Also remember that the ramp gets cut on its underside also, not just on top.
[ This Message was edited by: Daniel_Bingamon on 2002-10-27 09:30 ]
I just remember another thing that I used to do when I started making whistles. Waterflow - although water is not like air in it’s properties, you can see water and how it hits the blade. It was part of this water flow test that help me decide to use curved windways instead of straight, they seemed to give a more repeatable flow pattern.