Help needed with PVC flute dimensions

[monoRAIL]

I've decided to try my hand at a home-made PVC flute, and I'm using Pete Kosel's flutomat as a guide for the length and hole placement (http://11wall-west.com/~ph_kosel/flutomat.html).
However it's giving me very strange results.

Attempting to get lengths for an F flute with a 1cm embouchure hole I get 45cm for the length (embouchure to end), which seems way too long, that's longer than the E hole in my Tipple D flute. I cut this anyway to see if it'd work, but sure enough it blows an E flat.

Here's what I'm getting from Flutomat:



Does the algorithm not work for certain pipe dimensions, or am I doing something wrong?

[edit]In Inches, for the benefit of the Americans - it's a 0.86" internal diameter, 0.06" wall thickness, and Flutomat is suggesting a 17.83" length for an F.

[awildman]

I think your problem is your inside diameter. It is too large for F.

[awildman]

Disregard....thought was inches

[monoRAIL]

No problem, thanks for taking a look. I'm in Australia and the pipe I bought is listed as a DN-20 PVC Pressure Pipe, although it's actually 22mm internal diameter.

Doing a little reverse-engineering on the Flutomat, it seems that if you set your internal diameter to very close to zero, and the pipe wall thickness to zero then you get a flute length which is exactly half the wavelength of the note you're after, so this is the 'ideal' or mathematically perfect flute, which of course can't exist in reality. Then increasing the embouchure size, pipe diameter and wall thickness varies the length (and hole positions) to compensate for the extra distance the air travels.

However, a tiny adjustment in wall thickness can result in a very large change in length, for example a 1mm increase in pipe thickness results in a 2cm shorter flute! Perhaps this is correct, but to me it seems like a very large compensation in length for such a small change in wall thickness.

[Geoffrey Ellis]

Your wall thickness should have almost zero impact on the sounding length of your flute. Wall thickness will affect where you place your finger holes, but doesn't factor into the length needed from the embouchure to the foot in order to get the F note. Walls can be 1mm thick or 10mm thick. It won't matter (though the chimney depth would be out of control if you had 10mm thick walls . So if your software changes the sounding length based upon variations in wall thickness, then I can see that throwing things off.

Also, a 22mm inside diameter is quite large for a flute of this style in the key of F. Optimally you might look to either get a pipe with an inside diameter of about 17-18mm or opt for making a lower keyed flute. The 22mm is more suited to a low flute (C, B or Bflat). I make bansuri in the key of D with a 22 mm bore, but they are quite different from Irish flutes.

I've never used flutomat, but I have some experience with using similar software. My experience was that the software will get you in the general vicinity but you need to make some tweaks to get good results.

[awildman]

Years ago I made 2 PVC flutes in D and used this calculator for one of them. The bell note was great but the fingered notes were off. The other flute I used measurements that (IIRC) I found on Doug Tipple's website. This one came out much better than the calculator version.

[Feadoggie]

I've never used flutomat, but I have some experience with using similar software. My experience was that the software will get you in the general vicinity but you need to make some tweaks to get good results.

I agree with Geoffrey ... and I have used the Flutomat code. Here's how another flutemaker puts it ... (click on the pic)



If you look into how the calculations are done there are a few assumptions or assertions that are made with the variables. Your flute would have to match all of the assumptions to work out. Rarely happens. So you might view them as guidelines. It beats starting from scratch with no measurements though. Expect to make a few duds at first. Make a flute. Assess the results. Adjust your measurements. Make another flute.

And yes, I would use a smaller diameter pipe for an F flute. But! ... others have used 22mm pipe to make an F whistle. Take a look at Dr. Guido Gonzato's Low Tech Whistle designs. He has a design for a low F made with 22mm pipe.



The difference between the whistle and a cylindrical flute design is fairly straightforward. Use the position of the edge of the whistle labium as the center of your embouchure hole (assuming a smallish round hole) and you should be pretty close to the measurements shown. Remember, they're more like guidlelines.

Have fun.

Feadoggie

[monoRAIL]

Thanks for the tips everyone. I was a little reluctant to just go ahead and start cutting and drilling without a clear plan - all this talk of 'guidelines' is very daunting, but actually it turned out quite well. I hacked a bit more off the end of the first flute, and it was very close to an E so I decided it would be an E flute. Using Guido Gonzato's whistle specs, I used his hole distances, but drilled very small holes at first, which play much flatter than the note wanted. Then by enlarging the hole (mostly on the upper end of the flute) the note sharpens.

With careful use of a tuner app, and enlarging holes 1mm at a time I was able to get all the holes close to in-tune, although the sizes are not very consistent. The first octave sounds very nice, but it gets nasty in the second octave - very hissy and not in tune. I suppose this is just the nature of wide-bore, cylindrical pipes without any kind of tuning wedge.

I've already started on a second one, this time with a lip-plate and I might try to figure out a tuning wedge.

I have access to a 3D printer at work so I figure that would be interesting to experiment with. I'm also trying some whistle head designs to attach to smaller 15mm pipes, for alto whistles. Will post results when I get some that sound (and look) nice.

[Geoffrey Ellis]

In 1997 I started my career making Native American style flutes, and I remember that my first attempt turned out pretty well. I was using some basic books and following a template and I got lucky. It was fortunate that I did, because my next couple of dozen attempts were not so blessed

These days there are far, far more resources to help you craft a decent flute--just spend some time on YouTube and you'll find lots of basic info. If you are enthusiastic and don't expect overnight success you'll get there. To make really good flutes consistently simply takes time and experience. I've made somewhere in the neighborhood of 5,000 flutes and I'm still learning every day.

[monoRAIL]

Thanks again everyone for the encouragement and advice. Here's the results:


First attempt - it's ugly, but it works. This is an E flute, it sounds quite sweet.


Version 2. Added a lip-plate, which makes the lower notes much louder and richer. I cleaned this one up a little so it's more presentable. Washed the markings off with Acetone.


Went for a sharp upper edge of the embouchure hole, with about a 30 degree incline inside.


Cork stopper, and a beveled lower edge to the embouchure hole to make it more comfortable.

Here's what it sounds like: https://www.youtube.com/watch?v=TuKAq6-dG24
First octave is very nice. There's no tuning wedge so I basically stay away from anything above high F#


I also made a PVC whistle with a 3D printed whistle-head. More about that in the whistle forum here: viewtopic.php?f=1&t=101473

[Geoffrey Ellis]

Well done! That looks like a good beginning.

You might take a bit of sandpaper (say150 to 220 grit), wrap a small piece around some very thin dowel (less than 1/4") and use it to smooth the bevel of your embouchure cut. A really fine round file could substitute if you have one, but they tend to clog up sometimes. You could also use it (or an X-acto knife) to clean up your finger holes a bit, removing any rough bits of plastic.

[monoRAIL]

Thanks Geoffrey, I did buy a set of files recently for improving the finish of the holes, but I didn't get a dowel that small. Another thing for my shopping list on the next hardware store visit.

Today I picked up some PVC pipe labelled as electrical-conduits, it's in a hideous industrial-orange color, but it's a really good size - 20mm internal diameter and really thick walls, 2.8mm. I think it'll make a great D flute so that's my next target.

[Geoffrey Ellis]

Nice! Since plastic pipe is cheap, you might have a stab at a C flute as well (the 20mm inside bore would be better for that than for a D, but I suspect you can get a decent D flute from it).

[Feadoggie]

Nice work, monoRAIL. You've certainly gone over the edge and are now onto the slippery slope. The problem with these instruments is that you can't make just one. I am guessing there will be more.

I also made a PVC whistle with a 3D printed whistle-head.

I had a bit of a go at printing whistle heads a couple years back using a first gen Makerbot. My results were disappointing compared to what I can produce with a lathe and hand files. I moved on but I am eagerly monitoring technology as it develop.

Feadoggie

[monoRAIL]

Some D flutes in "Electrical Conduit Orange"

These are made following Doug Tipple's guidelines on his website: http://tippleflutes.com/making-a-simple-irish-flute/


Tried a circular and a squared-ellipse embouchure. They both sound very similar actually. The circular hole is slightly larger so that flute needed to be longer to be in tune.


I also tried beveling the holes, as shown on Guido Gonzato's Low Tech Whistle guide (http://www.ggwhistles.com/howto/).
The bevels feel very nice, and don't appear to alter the sound, however I fell that for fast tunes the non-beveled holes are preferable as you don't have to press as hard to fully close them.


The lip-plates are from a white PVC plumbing pipe with a slightly larger diameter and smaller wall-thickness. I leave the lip-plates unsanded and glossy which lets the lip stick very slightly to the plastic, whereas the orange pipe is sanded smooth for a matte finish, which feels nicer on the fingers. The surface is visually very like a peeled carrot!


Comparison with some other flutes to show the bore-size. First on the left is a Tipple D, third is a Dixon conical-bore, fourth is an M & E.


These pipes have a very nice size to them, slightly thinner than the pipes Doug Tipple uses but with really thick walls, which gives a nice tall chimney, particularly with a lip-plate. The color is a bit ridiculous, but I actually think it goes beyond ugly and has a certain industrial charm.
The sound is very similar to the Tipple (as you would expect, since I'm following his instructions) - I'll record a demo later.

I had a bit of a go at printing whistle heads a couple years back using a first gen Makerbot. My results were disappointing compared to what I can produce with a lathe and hand files.

Yes I also found the 3D printed whistle more of a gimmick than a real instrument. The extrusion printing just isn't reliable enough yet for consistent results so I think I'll stick with flutes for the time being.