Thanks guys. I will upload a video soon. I also ordered some more brass tubing and bought some brass screws to make a full brass version. The aluminium windway cover is prone to contact corrosion in combination with the brass. I was thinking about putting some food-safe lacquer on the inside to prevent that.
The idea came to me when seeing the square tubing in the hardware store, then I remembered that others have done it before, notably Paetzold with his bass and contrabass recorders, which he developed in the 70's I think. And Nick Metcalf also made some square prototypes, I think in G and A.
I started with aluminium, then made some from construction steel (which rusts) and two from stainless steel (which is incredibly hard to work with -- sawing the windway alone took a half hour). Then I tried the brass, which IMO produces the best results so far as it is harder than aluminium. The harder the better, it seems. The reason why people use hardwoods for whistles. I still have the plan to make a steel whistle but from round tubing as it is easier to cut with a pipe-cutter.
I wanted a construction without glue so I used the large screw to fix it all together. I constructed about 20 prototypes and so far also made a few in C and one in Bb which I modelled after a Generation Bb -- same windway width and length, so it does sound pretty similar.
Some advantages of the square design are:
- the handling, the whistle rests quite well on the thumbs, since it cannot roll (not that this is a "problem" on normal whistles)
- the holes are actually circles, which they are not on a round whistle if you use drills
- the holes can be closed easier and quicker, therefore the whistles are very responsive
- they are very evenly balanced over the octaves, which might be due to the elimination of some frequencies in a square tube as opposed to a round one
I used different materials for the fipple plugs, sometimes PVC, some I made with delrin and others with wood. The next will be made with wood that I cooked in linseed oil to make them more resistant to moisture. The problem is swelling of the wood which changes the sound when playing for longer times. But wood is just much nicer to work with than delrin (a true PITA to cut the plug from sheets of delrin) or PVC (possible toxins in the material).
I am also planning to sell these one day, once I am perfectly satisfied. The sound, response and handling are already great but the tuning can be an issue for various reasons (the workshop being cold is one of them). I will also try to construct a tunable version. For now I can link a video of Frank Claudy playing one of the aluminium versions and some videos I recorded myself.
And one video from David Hill: