I made a farily faithful copy of the Tartu recorder, but did not care much for the sound, so I am experimenting with similar size and shape inspired by it (won’t lok out of place at a ren fair) but with a different sound. Anyway, I have one on my bench now with a cylindrical bore that is 5/8" in diameter and 227 mm from lip edge to the end. I mix inches and mm because of drill bit sizes and the ease of doing math with metrics. It’s an E flat. I thought about shortening it to a different key, but I think I will just deal with it as is and make the next one a little longer as a low D. Anyway, I did the calculations for a whistle and drilled small (13/64") holes at the following mm distances from the lip edge: 97.6, 113.5 131.7, 154.4, 165.7 and 188.4. I am planning to enlarge and undercut them, but I wondered if anyone had suggestions based on similar sized whistles. It is hard maple, if that makes any difference.
5/8" bore and 227mm length edge to end makes it an extreme wide bore whistle with length to bore ratio ca. 14.7. I am not sure if it will work, the high end will be difficult to push. I try not to go lower than about 17 for that ratio.
You say it is in Eb. Is this the correct pitch? Seems to be a little too short for Eb. Also: what is the wall thickness? To calculate hole sizes/locations the wall thickness needs to be taken into account.
Generally for a 5/8 bore I would aim at hole sizes ca. 6, 10, 9, 6, 10.5, 9mm from top to bottom (sorry no inches!), but since you got locations of holes already fixed this is meaningless, and you would need to work your way upwards gradually increasing each hole’s size one at a time. Not sure what you will end up with.
Pete Kosel’s flutomat calculator can give you some ideas, but in your case you would be working back to front, by fixing locations first, rather than tone hole sizes first.
The text I am using for the basis of my experiments is “Musical Instrument Design” by Mark Hopkins. On the subject of optimal bore ratio, he quotes a source that suggests 23:1 for flutes then goes on with an explanation that makes it sound like there is a pretty wide range, though he mentioned losing overtones if the column is too fat. It is later in that book that I got the % formula for whistle holes. I am combining that with another book I have on making woodwinds that has no chapter on whistles and finally historical and whistle building tips and plans gleaned from the internet. Most of the later info is on using plastic and metal, but I am turning and boring my own tubes from wood, mostly maple to start with. Anyway, even with the little holes, it plays the scale though I do notice I like the sound of the lower register much better. I am boring some 3/8", some 1/2" and some 5/8", from around 1’ to start with to about 18" or so max. I don’t have a setup to accurately bore longer than that. I am a “learn by doing” type. 
To me the optimal length to bore ratio for a whistle is around 22.
I try to keep the design roughly between a minimum of 17 and a maximum of 26.
17 and 26 being the extremes which I find acceptable for a wide bore and a narrow bore whistle. 21, 22, 23 is the golden middle, standard bore. 20 and below I would call wide bore, 24 and above I’d call narrow bore. This is from my experiences and are my preferences. Other whistle makers may differ.
Flutes are much more narrow bore, their optimum is about 30 or 31.
For a 5/8" bore this means my optimum would be a Bb whistle, and the extremes a D (wide bore) and a G (narrow bore).
For 1/2" bore the optimum would be a D.
I don’t like percentage formulas for hole placement, as they just scale length, but not bore size, or hole size, or wall thickness, and therefore are not very accurate.
I wish you much success in your whistle making!
Thanks!
Those hole sizes and the undercutting made a lot of difference in the sound.It’s actually slightly more difficult to play, but with the right effort it sounds much better all across the range, especially in the high register. Not a great whistle, but very playable.
I checked out the calculator link. Wall thickness is tricky; I have been tapering it, so it is thicker at the head. Hmmm…
Thanks again!
I don’t get it. Surely choosing optimum hole locations, cutting undersized holes and then bringing them slowly to pitch with a reamer is the smart way to proceed.
At least, that’s how the hero did it in my time-traveller to the Indo-European invasion of Europe story. And he should have known!
I hope you did not just used those hole dimensions I mentioned, because I know they were wrong for the locations you gave! They were dimensions I would normally aspire to, and would be in locations which are ergonomic.
To make your whistle play better (and I don’t mean better in tune now), make sure all your tone holes are smooth, sand the edges, both inner and outer, a bit. Imagine air moving in and out rapidly, and you want to give it a smooth flow. Same goes for the window.
I went slightly below those sizes and then used a detail knife and tuner to slightly enlarge in the direction needed and undercut. Being in tune and being able to easily produce each note in tune are two distinctly different things, though.
I have detail sanding bits for my rotary carver that are perfect for sanding the holes. This type:
used with one of these:
In and out a couple of times and they are smooth as glass. Of course, I will have to use a different technique when I go to ren fairs. 
OK, if I may indulge further…
Here are a couple of in progress large bore whistles:
The small one up top is the one previously discussed. The bottom one is a low D. It is still in rather rough shape; I haven’t finished shaping it so there are tool/knife marks all over. But is a much more brightly figured piece of maple than the one above it. If I finish it carefully, it will look really nice. What would be really cool is if it sounded nice also. At 250mm length from the lip and a measured ID of 15.6, it violates the rules you suggested and comes in at a ratio of 16. My thoughts are to use the calculator you provided the link to and the wall thickness from the area where the holes will be (by measuring OD and subtracting then halving). I will work on something else for a day or two, in case some kind soul offers a suggestion…
I am going to drop to smaller bores for most of my whistles.
High D, not low D, surely.
I did not suggest rules, just a sort of empirical guideline I found useful.
If the length to bore ratio gets rather small you still can get a playable instrument, but with a difficult upper region.
Maybe I have my terminology wrong. It’s a D, but not a soprano. It has a big bore (15.6mm).
Talking recorders for a moment:
The foot long recorder pitched in C is usually called Descant or Soprano,
the next bigger size F recorder is called an Alto recorder,
the next bigger size C recorder is called a Tenor recorder,
and the even bigger F recorder is called a Bass recorder.
All these recorders play in a range an octave above the corresponding human voice range.
Transferred to whistles the standard ca. foot long D or C whistle would be a Soprano whistle. and the ca 2 feet long low D whistle would be a Tenor whistle.
Carved Tones, where did you get the Tartu recorder measurements from? Don’t know if your source was right, because the Tartu recorder has most certainly not a cilyndrical bore. It’s a multiple stepped one, with a flare at the bottom.
But I’d like to see it for myself, if possible, in any case.
I will have to dig through my “virtual stack” of articles, but it was described as roughly cylindrical even though there was a slight variance. It was noted in a couple of articles that body is slightly curved and the bore slightly elliptical, effects of time buried, and the variance was dismissed as a possible result also. But the authors seemed to be bent on proving it could be from early as possible and the taper was a problem. Anyway, if you are suggesting that a stepped bore might produce a better sounding instrument, you may be correct. The two whistles on my bench now are only somewhat inspired by it with regard to wood choice, general profile and general size (they are a little longer, though).
A disclaimer - I am new to whistles. I have a bit of experience with building string instruments, play the mandolin, a little paino and sometimes play an alto recorder. I am not a particularly good musician, but have a reasonable grasp of theory, at least the basic principles of keys and scales. I don’t pretend to be an expert and welcome corrections to factual mistakes and differeing opinions.
I am confused by your use of length instead of pitch. If one sticks to a specific length to bore ratio, then it makes sense. But my understanding is that the biggest factor in determining pitch is volume of the air column, so my large bore “whistles” (using the term loosely) are pitched much lower than smaller bore whistles of the same length. I need to use a better tuner and get some raw numbers. I trust the tuner I am using as far as getting an instrument in tune, but it doesn’t give the exact frequency.
I apologize for the running monologue, but have more to add per Yuri’s question about where I got the information.
I have the book “The Amateur Wind Instrument Maker” by Trevor Robinson. As published, it does not have the Tartu recorder in it. But mine does, as I wrote it in as an extra entry on one of the tables using the measurements I found surfing around. So whether my interpretation or the sources I found are to blame is hard to say. 
I did find this in a rather authoritative text (Estonian Journal of Archaeology > December 1, 2007):
The bore seems to be near cylindrical, conic by the block and mildly descending at the other end of the instrument. Still there is no doubt that the violation of cylindrical form is deliberate and not the outcome of deformation. The bore is slightly bent, while the existence of dirt inside the instrument and the oval form of the bore make it hard to measure the exact dimensions.
It was interesting that the author made that observation, yet later says:
Hundreds of years in wet environment, deformation under the weight of the soil and later conservation have undoubtedly changed the dimensions of the instrument, among others placing labium and windway towards each other. Thus the current musical qualities of the Tartu recorder, sound, articulation and temperament do not correspond to the initial ones and describing them as they are now would only discredit the instrument.
And one last quote from it matches what I wrote in my book, so I think this is the article I used:
The recorder is made of maple (Acer platanoides). (1) There are ornamental rings at the mouthpiece end (Fig. 6). External outline of the recorder is nearly cylindrical, resembling a bone in shape. Directly after uncovering (being soaked in water) the total length of the recorder was 250 mm and the largest diameter was 30.7 mm on the mouthpiece end. Its bore has a diameter of 12 mm at the end of foot section.
Obviously, I took some liberties and did beak the mouthpiece and used the “nearly cylindrical” comment to make mine totally cylindrical (though I did make the block area slightly conic). I am not trying to make an exact replica for a museum, I am trying to make a period correct (or defensibly not incorrect, if that makes any sense) instrument that will appeal to modern players.
NOTE - that instrument is not pictured and will not be; I cut the tube off just before the first hole. I am hanging on to the fipple block as a shrill whistle. Perhaps an opportunity will arise to give it to an ill mannered child of an ill mannered parent. 