Topic: Reed Shape - from the IDRS OnLine Archive

Shape Question (3/29/2003)

On Saturday, March 29, 2003, at 11:10 AM, John Campbell wrote:  Dear List:  All of my life I have used a fold-over shaper, therefore the cane has always been wet when I have shaped. I am now considering having a straight shaper made to my specifications. What are the differences in shaping wet and dry? How does this effect the width of the reed? How much does length of soaking time effect shrinkage when the reed dries.  John Campbell

By Norman Herzberg | Interview:
This is my opinion regarding John Campbell's question about shapers. First, with regard to the shrinkage, I shape the cane wet because that is the condition in which we use it. I have never found the shrinkage to be significant enough to be a problem. The following is a copy of an answer I sent to another bassoonist who asked about foldover and flat shapers.  Geneva  I am making the presumption that the machinist you took it to measured the symmetry of the profile of the sides. That is rather easily done with a comparator that projects the shaper image on a precision graph on a screen. The shaper can then be measured in minute sections by means of the calibrations on the comparator. Once the symmetry of the profile curves are assured, there still remains the task of comparing the corresponding faces of the shaper over which the cane is clamped. The spread of the cane over the faces has a direct influence over the shape you get. In other words, you can get a set of dimensions for the shape of a person, but you must take into consideration whether he is fat or thin, even though his widths are the same-fat or thin. Does he have a pot-belly or not? That alone will influence the fit of his clothing. To proceed, there is the problem of clamping the cane so that all of its natural curve is forced to hug all of the face of the foldover shaper. That is assuming that the faces match each other to close tolerances. Now comes the third requirement. When you shape the clasped piece of cane it is imperative that your knife is absolutely perpendicular to the tip of the shaper. If you cut the cane with your knife at an angle, you will get shapes that will vary with each shaping. That leads to unequal cane blades and throats, slippage in the blanks, and reeds with various widths. NONE OF THOSE VARIATIONS ARE POSSIBLE WITH A PRECISION MADE FLAT SHAPER. That is the reason I developed and produced a flat shaper with the precision I demanded. The essence of what I have designed, produced and sold avoids weak links such as I have described.I have some words about the shape I incorporated in my shaper. I am well aware that there are a variety of preferences, and many bassoonists want a wider shaper. Since the R and D for the shaper I make involved an expenditure of $3000, I had to devise a shape that would appeal to a large number of bassoonists. I also had to be sure it had certain dimensions that would help bassoonists. Those dimensions were especially necessary in the area of intonation. Wide shapers do well in the lower half of the bassoon, from middle Bb (top of the staff) down. Even then, one has to be very careful in trimming that the E (third space) does not go flat, and the C# does not collapse. However, wide shapers carry burdens above the forementioned Bb. The middle C is too low as are the notes going up. The middle D, the Eb, the E and the F have a tendency to be low. Those notes can be helped with the wire adjustment, but another factor enters the equation. The more you pinch the second and first wire, the more the tendency to produce a higher arc in the blade. The higher arc produces pressure on the sides of the blade and you have to use caution to avoid collapsed sides. That is where the correct bevel can stave off the inevitable collapse of the very sides of a wide shape. In addition, if you try to brighten the tone of a wide shape, it is dangerous to trim out of the tip at the middle. A safer way is to narrow the shape, and now you have the narrower shape I designed!  , Norman Herzberg

Yoshi Ishikawa
Professor of Bassoon, U of Colorado at Boulder
Editor, IDRS OnLine Publications
Administrator, IDRS Forum