MIMF

Hi Everyone.
This is my first post.
I'd like to take this opportunity to thank everyone who has taken the time to share their knowledge on this forum and other websites. It has been an invaluable resource for me.

I've been a maker of traditional and experimental instruments for many years. Recently I've started making fipple flutes from elder. I've tried out different fipple designs and had good success in the first register but continually fail to get good intonation in the second register and struggle to get past a high fingered A. On the flutes I've made, I get good overtones before drilling the finger holes and the overtone flutes I've made sound good.

I'd really appreciate some advise and guidance on getting good intonation on the second register and being able to extend the range of the flutes into the 3rd octave. I have done extensive research on the web and in books already but haven't come up with satisfactory explanations. So, I turn to this community.

I've attached photos of a flute I had at hand this morning to give an idea of what I'm making. It has a recorder style fipple but like I said I've tried other designs all of which have the same problems. The flute is not well finished because I'm still experimenting.

Looking forward to your replies. Thanks in advance.

In future I'll make sure the photos are the right way round, sorry!

Forgot to include specs for the pictured flute.
Length 330mm
Bore 16mm
Window 8x4mm

The flutes I have built are all side blown, not fipples, so I cannot be much help there. Your window looks nice and clean. Is the ramp sharp? But one thing I have noticed experimenting with flutes is that the hole placement and size can affect both the cross tunings and upper octave. Theoretically you can move any hole, with the appropriate change in hole diameter, and still get the same pitch. That being said, if you ALSO want the instrument to handle standard cross tunings and play well in the upper octave, the rule is not nearly as flexible as theoretically possible. I still have not found the perfect arrangement. Some experimentation with especially your larger holes may be necessary.

I've tried both sharpening and blunting the lip.
I've also tried adding material to the centre of the bore like a shakuhachi flute. This does lower the partial more than the fundamental but its not a practise I want to do.
I think the main problem is with the finger holes themselves although I still need to perfect my windway, window and lip and that should bring more clarity. I learnt somewhere that enlarging a hole affects the lower registers more than the upper but moving the position of a hole affects the upper more than the lower registers.
I think my next trial is to plug the holes with wax and shape them more up the bore which will hopefully bring the octaves more into align and, of course, make more flutes. It would be great is someone on this forum could verify this and shred some light onto this problem.

Fipple flutes are such mysterious things and the results are not always what you would expect whereas with string or percussion instruments the concepts are more straight forward.

Your flute is similar in size to a descant recorder, and looking at those I see the fingerholes (a) start closer to the fipple, (b) are smaller, and (c) are more widely spaced.

Might it be a good idea to start with similar spacing and smaller holes, and then tune each hole? (Note, I've only read idly about tuning, I have no experience myself, so this might be less sensible than it seems to me!).

I build guitars and ukuleles, and taking aspects of designs which are known to work is a good strategy there.