WTT: The blade

[Feadin]

Hello whistlemakers!

I have been looking at many commercial whistles and found most window size proportions are about 1 - 1/2, and the fipple plug usually is about in line with the top of the window, right? That makes me think that one thing I have left to experiment is blade design. I would like to know your experiences...

First, I would like yo know if your blade is:
- Right in the center of the windway
- A bit higher (outside)
- A bit lower (inside)
- In line with the roof of the windway (really outside)
- In line with the floor of the windway (really low)
and..... why?

Second, how do you make the blade? I mean, what tool or method do you use for getting consistency? I'm making curved windways so I believe that I cannot use a file or something like that... :roll:

And about the angle of the blade..... I've read a lot of things, some say a steep angle makes the sound less airy and louder, other say just the opposite... I would like to know about your experience with this, most than theory

Thanks!!

[brewerpaul]

First, I would like yo know if your blade is:
- Right in the center of the windway
- A bit higher (outside)
- A bit lower (inside)
- In line with the roof of the windway (really outside)
- In line with the floor of the windway (really low)
and..... why? Top of my fipple is in line with the bottom of the blade. The fipple plug fills the bore, and the ID of the bore is what defines the bottom of the blade.

Second, how do you make the blade? I mean, what tool or method do you use for getting consistency? I'm making curved windways so I believe that I cannot use a file or something like that... :roll:

I do indeed use files. I have a triangle file which has teeth on only one side. I start by filing at the right edge of the blade, filing a flat surface nearly down to the bottom surface of the blade. Then, I repeat this on the left. Next, I file the same amount in the middle-- at this point the blade is a rough three surfaced thing. Then, I file the angle between the three surfaces, making 5 smaller surfaces. These get refined and smoothed out until they approach a smooth curve. Back and forth from one side of the blade to the other until the blade reaches it's final thickness. I finish them with fine diamond files and 400 grit wet/dry sandpaper.

And about the angle of the blade..... I've read a lot of things, some say a steep angle makes the sound less airy and louder, other say just the opposite... I would like to know about your experience with this, most than theory

A steep angle seems to make for more backpressure and noise. A shallow blade is quieter with less backpressure. Also, I don't make the blade knife sharp-- with wood, this would be prone to warping.

[Feadin]

Thank you very much for sharing your knowledge!

I'll try using a small file then...

[brewerpaul]

use some scrap tubing and make some test blades to experiment with file angles, etc.

[RonKiley]

Thanks for the technique Paul. That makes a lot of sense. It is a little like the way I used to cut facets on gemstones.

Ron

[Impempe]

Hi Feadin,
Well I make whistles in a very similar way to you. I use a milling machine with a slotting cutter to cut the windway. This gives me consistancy as well as a lot easier than using files. being aluminium, the filling can get very tedious. I find that I need to smooth it with some very fine sandpaper and dull the edge to get the best results. As you said, the fipple block is lined up with the edge of the window but I find that a bevel on the edge of the fipple plug helps to get a better sound as does a rounding of the top edge of the of the windway as it enters the window. The floor of my windway is level with the cutting edge of the blade, because this is how it is designed and it sounds good on a curved windway. I have never tried to reposition this.

The angle of blade I have used has always sounded better with a steeper angle than a more gentle one. It sounds definatley louder and crisper, not so airy.

Give me a shout if you like on a PM and we can compare designs and methods.

All the best with your experimenting
Ian

http://impempe.mysite.wanadoo-members.co.uk/

[Feadin]

Ian:
Thanks for all the info!
Nice whistles you got there, I like the design

I've been experimenting a bit with the plug chamfer or bevel, and it REALLY does sound a lot better with it.
I've moved the blade a tiny bit up from the floor of the windway as well, and that helped too, made the sound... I don't really know how to describe it, but more "focused" or purer, and a bit more balanced in quality betwen the upper and lower notes. Now it sounds a bit less airy

[billw]

Ian:
Thanks for all the info!
Nice whistles you got there, I like the design

I've been experimenting a bit with the plug chamfer or bevel, and it REALLY does sound a lot better with it.
I've moved the blade a tiny bit up from the floor of the windway as well, and that helped too, made the sound... I don't really know how to describe it, but more "focused" or purer, and a bit more balanced in quality betwen the upper and lower notes. Now it sounds a bit less airy

Couple of things about blade and plug -- my experience has been that a shallow blade angle makes for more of a tendency to "squeak" in the lower register, while a too-steep one (steeper than about 40deg) can make for an "airy" whistle. A quick trim of the bottom edge of the blade with a machinist's scraper will also raise the bottom of the blade a tad higher in the windway, making for a purer tone. As to the plug, I'd recommend radiusing the edge, rather than chamfering or cutting an angle. Discussions with Dan Bingamon, and reading all about the Coanda effect, have tended toward indicating that the chamfer or bevel won't do nearly as much to pull that bit of air downward as a slight curvature will. You'll have a somewhat louder and "purer" whistle for it.

Have fun!
Bill Whedon
Serpent Music

[Impempe]

[/quote]Couple of things about blade and plug -- my experience has been that a shallow blade angle makes for more of a tendency to "squeak" in the lower register, while a too-steep one (steeper than about 40deg) can make for an "airy" whistle. A quick trim of the bottom edge of the blade with a machinist's scraper will also raise the bottom of the blade a tad higher in the windway, making for a purer tone. As to the plug, I'd recommend radiusing the edge, rather than chamfering or cutting an angle. Discussions with Dan Bingamon, and reading all about the Coanda effect, have tended toward indicating that the chamfer or bevel won't do nearly as much to pull that bit of air downward as a slight curvature will. You'll have a somewhat louder and "purer" whistle for it.

Have fun!
Bill Whedon

Thanks for those tips Bill. I don't like to fiddle with a design that seems to work, but your suggestions certainly are worth experimenting with and louder and purer sounds a good goal to aim at. Could you advise what a machinists scraper is. I assume that one could do this with a file as well?

Ian