Anyone here made one? how different is it from making the high D? i know there are some differences in the shape of the blade and fipple block, but aside from that is it basically the same? any advice?
I plan to cast the blocks from liquid polymer, like i did for the high D.
Is there a chance that something like the fajardo wedge would improve the intonation on a low D as it does in a flute?
I have not made a L-T low D. I have made a lot of low D’s of my own designs in PVC.
Using the L-T low D design the wall diameter dictates the windway height so that is an issue to start with. So figure out what pipe you will use. If you choose something thin walled, that’ll keep the air requirements within reason. And it will be a bit more flexible and that should help when you clip the outer mouthpiece cap onto the head. The trouble with using a thin walled tube on a low D is that it limits the window depth. That can contribute to a shaky tone. I’d build up the sides of the windows. The first way to do that is to extend the length of the cap past the window. Cut a notch out of the cap to match the window dimensions. That will double the depth of material around the window.
You could also start out with a thicker pipe for the body and find a compatible thinner pipe just to make the outer cap and maybe a tuning joint. Use a small strip of the thinner pipe to reduce the height of the windway from the inside of the cap as Guido describes. Thin walled pipe could also be shaped to use as an internal choke at the bell end if you want to play with one of those or other creative bore constrictions.
I see little reason to change the geometry of the other head components personally but you should do what you are comfy with.
It is true that the tuning differences between the octaves is more obvious on a low D than a high D. Some makers start tuning from the first octave. I’d suggest tuning the second octave and working backwards if you see a big stretch between the octaves. I’ve messed with the Fajardo wedge and the Sandner spike and a couple other arrangements on low D’s. I am not entirely satisfied with my experimental effects using a wedge or a spike. Basically if you reduce the volume of the cross section of the head it will theoretically have a positive effect on the stretch between the octaves usually in the upper 12% of the bore or so. I have developed my own arrangement. It’s nothing radical. If you look closely at the better low D’s on the market you will ferret out some rather straightforward solutions to the problem. I would, in any case, suggest you do your own experiments.
The cast plugs for a low D require either extra catalyst or additional curing time to get a solid plug. So take some care there. Using casting resin for a low D plug opens up some fun stuff you can do. The space is large enough to cast small objects into the resin or you can mix and swirl colors. Have fun.
Let us know what turns out.
Feadoggie
I bought a length of 1" cpvc, as the bore is about 22mm, which is what guido uses, and is spec-ed in the plans.
This is what i’ll do then, thanks for that! btw, what would a choke do?
I guess I’ll look at this diy whistle as one to practice on, not to play with others just yet. also, how would you start with tuning the second octave? just as the first would be done? GG says that the lower octave can be a bit sharp and it won’t be noticed as much as a flat second, so i assume that’s the principle i’m working with–tune the second just ever so slightly flat and the first will be ever so slightly sharp. then of course, intonation is another matter…
(edited to say–probably i have that all wrong…)
(another edit-this time a quote, GG says “…bear in mind that high-pitched notes stand out much more than lower-pitched notes. While flat high notes sound really horrible, sharp low notes may go nearly unnoticed. Keeping all this in mind, you may want to tune the second octave D (or the equivalent base note) just a bit sharp, e.g.\ 5 cents. The second octave will sound in tune, the first octave will sound slightly sharp.”
I’ll add extra catalyst, but not too much right? i assume too much would cause shrinkage, or cracking, or brittleness, or some other negative side effect.
Thanks for your suggestions, Feadoggie! i knew i could count on ya! 
there will be more questions, so stay tuned!
You might get a variety of answers to what the choke point provides. But it certainly has played a part in the evolution of wood wind designs over the centuries. I’m talking about a choke point at the bottom of the tube. Basically it attempts to increase the impedance in the tube. It does effect the virtual length of the tube so take that into consideration if you experiment. The choke has been used to effect tone and timbre as well as to assist in the tuning of the higher registers. I believe that the use of choke points in flutes/recorders was abandoned in favor of conical bores as improvements in manufacturing technology allowed. I have two low D’s from a well known maker here that employ chokes. Newer models from the same maker do not.
Yeah, easy for me to say; harder for you to do. I think this is what Guido Gonzato may have been addressing when he wrote about the sharp first octave. How you go about doing it is up to you. And I guess that way I approached it at first was by calculating the hole positions and making a whistle. Then realizing the top end was noticeably flat I started sharpening the b, a, and g notes to get them closer to being well tuned. That, of course makes the first octave a bit sharp. Basically you want to split the differences between the octaves. So you end up with something a tad flat at the top of the second octave and a tad sharp at top of the bottom register. Then you can blow things into tune as you play (marvelous what our brain, ears, lungs and hands can do with no effort). Now that is a strategy for a strictly cylindrical bore. Once you start constricting the bore at the head or choking the bell end you might go about things bit differently.
Oh and finishing the holes smoothly at the bore helps high notes speak. So you might want to do that before you start moving the hole positions.
Does that make any sense to you?
My hope is that since you have the same pipe size as Guido uses and that he has already been through the hard part that you will be darned close to start with. The whistles that I have here from Guido are very nicely tuned so I would have some confidence in his specs.
Yes, don’t add more than little more catalyst. My caution comes from not using enough catalyst initially and I ended up with a batch of plugs with a tacky exterior and a liquid center after a week of curing. So you may have to experiment a bit. The good news is that it does work a treat in the end. You’ll still get good plugs that fit the tube perfectly. Molding plugs is a very smart strategy when you don’t have a lathe at your disposal. It should be the first option used by DIY whistle makers. It beats sanding dowels down by a mile. Just takes time for the curing and a little cash for the resin.
Feadoggie
goddammit i forgot to put the releasing agent on my casts! sigh. we’ll see how that goes…
got the windway partly done though, and found some ‘pipe’ that fits pretty snugly over the whistle pipe. maybe too snugly, but with some lube I think it’ll work as a tuning slide and a windway cover.
how steep an angle would you use on the blade? 45 degrees? steeper? less steep? Mine is turning out less steep.
(Feadoggie, thanks for all your awesome advice!)
I wouldn’t worry too much about the release agent just yet. At least the resin I used didn’t seem to actually bond to the CPVC pipe I used as the molds. They won’t just pop out though. You may just have to push a bit to get the plug out in the end.
That’s a subject for a whole treatise? It is really up to you. 45 degrees will work fine in any case. It’s one of those things you should experiment with to see the effect it has.
Feadoggie
I’d go even farther than Feadoggie, and argue that there is no right answer to this question. It isn’t clear to me that there needs to be any ramp at all. What I have found is that, for the sound I want, the top of the lip should be cut straight across, rather than curved with the circumference of the pipe. I find the curved lip makes a rougher sound than I want. Other makers make other choices.
The Wikipedia article on Fipple says, without a supporting citation:
Typically, a shallow ramp instrument, such as a tabor pipe, will allow faster register changes, pitch bending and “flutey” tone, while an instrument with a deeper ramp will limit fast register changes, pitch bending and produce a more “reedy” tone.
In contrast to this, I have a whistle with a very blunt lip that gives quite clean register changes.
We agree, Tunborough. 
I merely suggested some experimentation. Fearfeasog mentioned 45 degrees as a point of reference. And that will work, as will many other arrangements. I rarely prescribe whistle design elements instead favoring to advise DIY makers to come to their own conclusions. More fun that way and hopefully diversity is the result.
Fearfeasog, there is a lot of information written about ramp angles, blade sharpness, etc. pertaining particularly to recorders. There is also a standard “thinking” pertaining to the effect these have on timbre and response. Some of it seems to be “popular science” and some of it seems to just plain be mythology. If you have the time and the inclination you should do some experiments yourself. There’s no harm for instance in starting with a rather blunt ramp, testing it, and shaping it further until you are satisfied.
If the point (no pun intended) of the blade is to split the air stream and induce turbulence then sharper and smoother may not always be better.
Feadoggie
I am not sure what you mean here (what I put in bold in the quote), I cannot picture the shape of the blade. Do you end up with a blade which edge is curved when viewing the window from above, so that it’s centre has a wider distance to the windway exit than it’s edges (so the window appears not as a rectangle, but more like a “D” when viewed from above)?
yeah that’s a good question–or do you just file it less and let the sides of the blade remain thicker than the center? experimentation!!!
Sorry I wasn’t clear.
When viewed from above, I always want the window to look like a rectangle. I don’t like the sound when it looks like a “D”.
I’m referring to the shape of the business end of the blade when viewed by a daemon sitting in the windway. For a lot of whistles (e.g. Generation), the sharp edge of the blade would look like a straight line. There’s a Sweetheart here where it would look like an arc, concentric with the cross-section of the tube–this is the curve I’m speaking of. On recent LTWs I’ve made, it tends to look, well, like the side-view of a bridge: curved on the bottom at the inside of the tube, and flat on top. The flat top is what I meant by “straight across”. The top and bottom (as seen by the daemon), may meet in the middle (sharp blade), but more recently I’ve been leaving them some distance apart.
But now I’m looking at a whistle I made where the top of the blade does have a bit of a curve to it, and I don’t have any complaints about the sound. Sigh. Feadoggie’s right, fearfeasog, … come to your own conclusions.
Thanks! That sounds like a fairly blunt edge.
To me the sharpness/bluntness of the edge produces distinctly different voicing.
The more blunt or rounded, the purer the tone (other factors left aside).
I usually file my edges sharp (file a sharp even ramp), then blunt them (round them) till satisfied with the tone.
then there’s this from Guido’s instructions:
"Rigging the Fipple
When you make an alto or low whistle, the fipple and lip need an > important > modification:
you > may > sharpen the lower edge of the lip, too, to make the sound less breathy;
this time you > may > bevel the fipple block (see figure) to make the bottom notes stronger. Do not exceed 1.5 - 2 mm for altos, 2 - 3 mm for lows.
These tricks were kindly provided by Jem Hammond. Thanks! "
(my emphases)
(The “important” part suggests “necessary” to me, since these are instructions after all! But the “may” part suggests it’s just an option. as does the “tricks” bit. only slightly confusing)
When he says “sharpen the lower edge of the lip” do you suppose he means make it a 90 degree angle? Otherwise I suppose he’d be saying “bevel”.
Obviously everything is optional, and I have the extra fipple blocks to play with (I poured 8–4 may not come out of their pipes!). I’ll let you know how it goes. As I say, too, I have found some pipe/tube/whatever that seems like it’ll work as a tuning slide so I can make one well tuned body and try different heads. FUN! I really hope my first low D sounds as good as my first high D did. But I won’t get my hopes up.
Since those tips originally came from Jem maybe he will chime in and share his reasoning. Jem. Oh, Jem.
We all do things a little bit differently. It’s a matter of what works for you in my book.
Sharpening the lower edge of the blade sounds like it is talking about undercutting the blade a bit. I could be wrong. Jem will have the definitive answer. It does not say what effect it has on the finished edge there. Undercutting brings the underside of the labium up a bit. If you aim the jet a little high that can help line things up. If you are aiming the jet properly already it might hinder tone production - too much wind under the lip to cause a standing vibration. You can sight through the windway to make a judgement call if your tone is weak as to whether you think you need to do that.
The bevel of the block in the illustration also helps lower or pull the jet downwards a bit. Rounding or easing the exit edge of the plug is my standard practice. YMMV.
If the plug is the proper size for the pipe, and it should be since you are molding them from the same pipe, easing the edge of the plug should be all you need to get a strong tone. Still I run the fine file under the blade more as a deburring exercise than an undercutting action. On occasion I get a stubborn case that needs a bit of an undercut. It’s a dance of many variables. If you are patient and look things over with an analytical eye you should be able to assess what you need to do.
Feadoggie
thanks for that.
I popped one of the blocks out of it’s mold (done in one day!!!) fit it, beveled it, covered it, beveled the mouthpiece, and voila! a beautiful sound! My own two note low whistle!
tomorrow I shall make it multi-notal!
Only having played one low D ever, (a susato) and that for only a few moments, I wonder if I’ll even know if it’s a good player. I guess if I can make all the notes, I’ll be doing better than I could have hoped for.
wow, the thing is made! fipple block not permanently installed yet, but it actually works and doesn’t sound horrible. I really like it–the grip thing is tricky, esp. trying to play the middle C# without dropping it. 
the upper and lower registers are really different. i’d say more different than a high D. is the lower reg supposed to sound sharper than the upper? I’ll have to recheck that. Also the whistle ended up 5 or so mm shorter than guido specced–all the holes moved back 2-4 mm. dunno why–windway size? fipple block distance from the blade (approx 8mm as guido specced)
Once I’ve played with it a bit I’m planning on cutting it’s head off and making some new heads to play with. that sound’s so wrong. call me fearfeasogenstein.
Huzzah!!! 
Is the low register sharp or is the upper register just flat (which is par for the course)?
The difference between octaves is not particularly surprising. As I said earlier, the low D accentuates the flat top end issue. It’s not as easy to make a well tuned low D as it is to make a well tuned high D, IMO. It’s bigger; it’s badder; it’s brutal-er; it takes more air; the intervals are stretched out, etc.
Off with its head, as they say. Make your slide. Using the slide, figure out where the individual holes give the best tuning one by one and keep track of the distance between the blade edge and center of the hole. Do the same for the tube length for the bell note. Then make a new body using your latest measurements. Check out how the new body works. Repeat as necessary. It’s all down hill from here. Your head sounds like it is working well.
Cookbook whistle making usually does not work right off the bat. I can assure you that Guido Gonzato makes good, well-tuned whistles based on the ones I have and those others I have played. I know a lot of fairly skilled people that have taken a favorite whistle, measured it and then set out to knock off a copy. They outcome is rarely close to the original in tuning or timbre. It is also not always obvious why that is the case either. You can observe this by taking commercially made whistles and measuring them up and putting the measurements into a proven tone hole calculator. You’ll observe some differences between the real world whistle and what is predicted by the calculator. Some of that has to do with the calculator’s built-in fudge factors or “end correction variables” but that doesn’t account for all of it.
Little things matter. It’s a dance of many variables. You have to like dancing. Enjoy the dance.
Feadoggie
Let me add my own experience to this chorus. Having successfully made an excellent alto A whistle and several high D’s using GG’s method, I set out last winter to duplicate my beloved and no longer available Hudson Winds conical brass high D. I even had a machinist friend who makes bells and other brass parts for trumpets, french horns etc., help me with the complex fit and shaping of a tunable, conical bore instrument. With my copy and the original sitting side by side, I would defy even Peter Bonsteel (brilliant designer and crafter of the Hudson Winds, wherever he may be) to find a cosmetic difference.
But my version sounds terrible. Tuning is fine and very similar but the octave jump is far too easy and the bell note almost unplayable.
I’m convinced that it’s the finish and edge of the blade that’s the problem. Fortunately I made two of them and they are identical. After brooding about it, and destroying the blade of one in a feeble attempt to correct it, I am making another head this summer.
It is absolutely about the “dance of many variables”.
ecohawk