DIY tuning for both octaves for wooden whistle

[catnip]

My last post was back in 2002 and since then I have been making violins (mostly Strad models) for the past 18 years but for a summer diversion I decided to make a tunable wooden whistle based on a O'Riordan model.
The first prototype with a cylindrical tube was OK but the second octave is a bit flat with normal breath. My second experimental prototype with a conical bore is out of tune since I used cylindrical hole spacing. Before I complete the tuning on my third with a cylindrical bore I thought I would ask here if there are tips and tricks for tuning for both octaves and what the best compromise is. Each hole has a contributing factor not just the closest open hole. The basic diameter of the whistle is 3/4" (OD 19 mm) with a 1/2 " bore (ID 12.6 mm)
How do you widen the hole? Make it wider? Lower it a bit? Raise it a bit? I have read the usual hole tuning advice but they don't cover the octave issues. If the lower octave is in tune it seems the upper octave is flat. Any expertise help would be greatly appreciated.

[pancelticpiper]

I'm no whistle maker, but I have tuned dozens of whistles over the last 45 years, which came to me out of tune (in an amazing variety of ways).

For my aftermarket tuning, to get a whistle in tune I need to start with a whistle that has good octaves.

If the whistle has a built-in flat 2nd octave moving the holes around isn't going to do much to fix it, because whatever note you get in the low octave is going to be flatter in the 2nd octave.

That's the overall stuff. For sure with Baroque flutes the makers would come in with special tools and make subtle perturbations in the bore, and do things with angling holes and so forth. That was due to each finger-hole being responsible for a number of different notes, functioning as a tone-hole for a number of notes and as a vent-hole for a number of other notes.

Trad Irish whistles aren't like that. For old-school trad playing you only need two octaves and the only finger-hole that's responsible for more than two notes is Hole 1 which has five functions

1) the note C# in the low octave
2) the note C natural in the low octave
3) the note C# in the 2nd octave
4) the note C natural in the 2nd octave
5) a vent-hole for Middle D

and, if you want to venture into the 3rd octave,

6) a vent-hole for High D.

Otherwise each finger-hole, holes 2 through 6, only has to play its dedicated open note in two octaves.

IMHO you should get the basic design corrected so you have in-tune octaves. Everything else comes from that foundation.

Once holes 2 through 6 give in-tune octaves, then you can move them around to get a good scale.

[Tunborough]

For adjusting the octave balance with a cylindrical bore, take a look at this thread: viewtopic.php?f=1&t=108141. That is probably the easiest solution to your problem.

If you want to use a conical bore, not just any cone will do; it has to have the right taper to balance the octaves.

For tuning calculators, WIDesigner is the only one I'm aware of that explicitly takes both octaves, and bore profile, into account: https://github.com/edwardkort/WWIDesigner/wiki.

I have heard that you can tweak the octave balance for individual notes by undercutting toneholes on the upstream or downstream edge, but I have not tried this myself.

[Sedi]

As a rule of thumb - bigger holes sharpen the 2nd octave. Just be careful with the top hole if you want an in tune cross fingered C natural oxxooo. If the top hole is too big, the C nat will be sharp.

[catnip]

Thanks for all your input. I read the thread posted by Tunborough ( a big thanks) about raising the pitch of the second octave by using a small tubular insert at the head. I made several trial inserts of various lengths from 1/2" brass tubing that fits quite nicely into my 17/32 body extension: 8 mm, 12 mm, 16 mm, and 20 mm. The one that worked the best was the 8 mm. I also inserted a small 5 mm insert at the bottom of the body.
Now it plays fairly well up to the high B. I rarely go beyond a high B out respect for fellow musicians.
Now I am going to make a second one and see if I can duplicate the sound