After Brian’s excellent posts last week here’s a small video of an audacious idea. What do you think? Could it work?
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mk Whistles After Brian’s excellent posts last week here’s a small video of an audacious idea. What do you think? Could it work?
7 replies on “Fabric Hinge”
The Fabric hinge looks like it could work. I take it that an actual production key would ultimately be less bulky, curved and shaped for a comfortable touch and appropriate appearance, probably fitting more closely to the body of the whistle? Some of the bulk looks to be from how your test model is attached to the tube for rough test purposes. Looks like the edge of that attachment is also acting as a pivot here, which I suppose would properly be a part of the underside of the key.
To expand on my earlier (In Depth: Part 1) comment about pivots (particularly in regards to offset keys), you can shape a pivot so that it operates in different ways depending on where it’s acted on. That is, you can build up an area to limit motion in an unwanted direction. Think of a 3-legged stool. If you had 1 leg (or point), not so good – quite a balancing act, and lots of wobble. With 2-legs (or a straight ridge under a key), you have more stability, but still some dangerous directions you don’t want to lean, or you’ll topple right over. With 3 legs, you can limit the motion so as not to wobble (sometimes even better than 4 legs). In another example, consider a camera tripod, where the legs might differ in length to hold steady on uneven ground. This serves to maintain a particular orientation, and prevent undesired rocking.
Kevin, yes, I think the idea is that it would make the keys much more streamlined. The test rig is still a bit cumbersome. Some further experimentation
As to the pivot point: very interesting to hear what you are saying. We actually started with no solid pivots at all as in this video >
http://www.mkwhistles.com/video/simple-leaf-spring-key.html
The main concerns here seemed to be:-
1. The key pad wouldn’t return to the same place each time and so the seal could be compromised
2. Making the spring lighter to give a good key action left it being not quite robust enough
3. any offset force caused the key to twist in actuation (not a problem in itself, but might affect the ‘positive’ action of the key)
Having one pivot point on the far side of the key to stop the twisting would sort out #3, but #2 (and possibly #1 starts to need the second pivot. Three pivot points would seem to restrict the keys movements totally (maybe a bit two solid!). These realisations (if they are correct) were a little disappointing as we liked the simplicity of the original no pivots/axel idea.
M
Misha, not sure I understand your #1 above. Why WOULDN’T the key pad return to the same place each time? Is it possible that your problems there are only due to the rough modeling you’re doing for testing? You know, taping on springs to the tube, things like that. You could machine grooves, slots or dimples in the tube to keep leaf springs seated, or keys aligned, and have that be a simple enough job given an appropriate jig. Right now, I think I see you utilizing strapping, or a spring that wraps around the entire tube for temporary placement. I guess one of the sketches is showing riveting the spring through the tube.
I assume you want to come up with the most simple solution possible. Keys should be easy to cut and shape, and sufficiently uniform to not make each installation a custom job or a maintenance nightmare. You’re getting that possibility with the key system you propose.
To clarify about pivots, the reason I mentioned the tripod adjustable leg example, is that you could have points/pivots that are sized and placed such that they do not interfere with each other, and only strike when a certain situation occurs. ie: if a normal, in-line touch on the key, a particular point is the active pivot; if an offset touch, then a different point will come in contact with the tube, and either direct that action, or restrict the unwanted behaviors.
Not sure if this will format correctly. This time, think of a 4-legged table, often encountered at a restaurant, resting on an uneven floor.
1
2 3
4
Assume leg 4 does not meet the ground, and the table is supported on legs 1, 2 and 3. It’s not going to rock from leg 2 to 3 at all, but will from 1 to 4, unless you put a spacer under leg 4 to make the installation rigid. OK, maybe this doesn’t clarify anything.
Nope, took out my spaces. Imagine a cross, 1 at the top, 4 at the bottom, 2 and 3 at left & right
Gotya! I like that idea a lot. It could potentially mean that one key could have two touchpads, and give you two notes depending on which touchpad you press. At the moment we’ve just got one touchpad on each key – in this scenario same two pivots would always come into play because the key is always actuated from the same place, but I wonder if it might have an application with getting the low c#, C and B. I can definitely see how at least two notes could be got with the ‘stool leg’ theory. Fantastic. At some point we’re hoping we can build a Toob Chromatic F that reaches down to the D and it might be worth experimenting with this to get the extra notes with fewer keys.
[…] play with the aesthetic. The question remains though: can we make it work? I’m optimistic. Here’s the very first iteration of the […]
Don’t know if this was covered elsewhere in any comments, but keys above the bell note tube length are normally “closed” keys.
On a D flute, for instance, Eb is normally a closed key, and using the key’s touch vents the hole to effectively shorten the tube.
Flutes with a short foot (no foot keys, except perhaps Eb) are constructed such that the full length of the tube gives the D bell note. Flutes with a long foot essentially vent at the C# hole to play D (with the open C hole helping vent to sharpen the pitch a little).
The low C# and C keys are normally “open” holes, the reverse of usual, and a key-press closes them, effectively lengthening the tube, with the tube length suited to C or further down.
So, for a low D chromatic whistle, the whistle would 1) Need to be longer overall than a key-less low D; and 2) You’d need to have a 2nd sort of key mechanism than you’ve been playing with currently, to accommodate the normally “open” positions. Otherwise, the player would have to hold those key-touches down to keep those lowest holes closed, which might require more fingers than we’ve got.