Vibrational Modes of an Uilleann Pipe Reed

[Jim McGuire]

http://www.tuftl.tufts.edu/mie/Pubs/uilleann_reed.htm

[brendan lewis]

I wonder if the cut-off point might also represent the "0" point for chanter effective length?

[jqpublick]

Wow, that was a great read. Thanks Jim. I've been wanting to buy material to start making my own reeds and that gives the the kind of basis I need to futz around with making reeds. Thanks again.

Mark

[Phil Wardle]

I wonder if the cut-off point might also represent the "0" point for chanter effective length?

I'm not sure about that, Brendan. It merely seems to represent the point at which the cane assumes what would otherwise be its non-stressed natural shape (after the slip has been gouged). Its "acoustical" length, and hence the relationship to nodal points at various frequencies/ harmonics would seem still to be the tip of the reed. But I'm not really sure of that either....after all, for a start, with some reeds the actual closure point can be some distance further in...especially if the sides are trimmed at 45 degrees and/or the extreme tip is feathered very thin. In addition, because of the contraction of the "bore" at the eye of the staple and the expansion of the staple/bore thereafter, this point may be the actual start to the "acoustical" bore.

What is frustrating is that this study is so preliminary...I really just wanted them to keep going and take it further....so that I could find out the meaning of life!

Very interesting stuff though, especially since even these very rough measurements seem to validate basic reed making procedures; an example is the of easing the top A, for instance.

A slightly different topic, that relates to all this, but which is perhaps far more basic and therefore of even greater importance, is the basic outline and tying-on method of UP reeds in general, even compared to say the blade shape of GHP reeds and in particular NSP reeds, with their characteristic parallel blades very shortly above the staple.

In my early reed making days on a Bflat set I used to make UP reeds in a way that was very similar to NSP reeds (i.e. parallel sides from about 5mm above the staple), with otherwise normal flat set dimensions, because that's the way Geoff Wooff showed me (its all we knew at the time). Happily, it was also easier for a learner to do, and they worked quite well in flat sets (or perhaps so we thought).

Now , the point is this. I have recently made reeds that are not tied on at all, just two parallel slips (with no tails cut in at the staple end) bound at approximately the staple eye by wire, with two wedges under the slips on the staple side to adjust blade compression, and with a conventional bridle a bit further up...which, because of the parallel sides, can be moved higher and lower at will, without harming the reed at all. The gaps around the staple were sealed with a variety of flexible methods (plumbers tape/poster putty/wax).

Surprisingly, they worked, and very well indeed....though the scrape had to be different. One can just pop the reed head off, as if it was a clarinet/sax reed and replace it on the staple with another. Or alternatively, quickly change the staple should it prove to be the wrong dimensions. No binding at all, at all!

None...I repeat, none.

I'm still fooling around with this totally different approach, as I have yet to work out the optimum dimensions and scrape shape...but so far (with what otherwise would be overly hard cane) it is showing signs of promise (no sense in throwing out cane that might lead to something new).

I have long suspected that the model of all double reeds we are using is mainly one of tradition and habit (stretching back to antiquity remember) rather than the only way to skin our cats. New paradigms are more than possible with what are basically bits of stick...especially when one considers the space-age laser interferometry gear we are using to describe our 3,000 year old technology, in the attempt to get it just to work well and play in tune.

Things still suck reed wise really, and we should do a lot more to get smarter.


Cheers, Phil

Edited to correct an error. The reed blades were parallel some 5 - 6mm above the staple, not the "binding", as stated. As an addition, the blade shape went from parallel at the top of the binding to the O/D of the staple at the eye end, in a concave curve. No attempt was made (by me at least) to "wrap" the slip around the staple. It was the initial hollowing of the slip that gave the inside of the reed its penultimate curve and resultant volume, i.e., before the bridle was emplaced.