Square vs hexagonal (or octagonal) bellows

[DaveRo]

17 hours ago, Łukasz Martynowicz said:

Just last week I’ve made some preliminary tests of new printed lever design that allows for curved levers, which are absolutely necessary to solve reed placement and lever routing problem on Haydens.

Curved how? My Peacock has some curved levers - curved in the horizontal plane (with the buttons vertical) - that is they go around other buttons. Those pads therefore do not drop vertically onto the holes. (I have a problem with one of these.)

 

It's not clear from Edward's pics at

https://facebook.com/groups/335284551953621/

but it looks to me that some levers go over others, so the pads land vertically which I think is better.

 

BTW, when I saw Edward's 'sine wave' pattern on the end covers it reminded me of a flat plastic air-vent I had: I could rotate a knob in the middle and close the holes. I wonder if you could build in a similar device - a sliding plate which reduces the holes and muffles the bass?

Edited January 7, 2023 by DaveRo
Changed FB URL to non-mobile one, again

[Łukasz Martynowicz]

5 hours ago, DaveRo said:

Curved how? My Peacock has some curved levers - curved in the horizontal plane (with the buttons vertical) - that is they go around other buttons. Those pads therefore do not drop vertically onto the holes. (I have a problem with one of these.)

 

It's not clear from Edward's pics at

https://facebook.com/groups/335284551953621/

but it looks to me that some levers go over others, so the pads land vertically which I think is better.

 

BTW, when I saw Edward's 'sine wave' pattern on the end covers it reminded me of a flat plastic air-vent I had: I could rotate a knob in the middle and close the holes. I wonder if you could build in a similar device - a sliding plate which reduces the holes and muffles the bass?

 

We talked a lot with Edward during development stages of his boxes and yes, we have talked about such a variable opening. It isn't viable, as it changes the tuning slightly, enough for some reeds to go out of tune. But his sine wave pattern allows for customisation of timbre on order, as he can change the density of those "spokes". But from my personal experiments I must say, that a concertina with mixed LH/RH timbre to make RH stand above LH more doesn't sound all that good. It is one of those ideas, that look good on paper, but if RH is bright and LH is mellow/muted, my mind perceives LH as broken and faulty.

@ curved - yes, in horizontal plane, to go around buttons and pads. Every Hayden needs those, or else you have to increase the box size or work with very short levers, or place the padholes in suboptimal or straight up wrong places of the chamber, which alters the sound and response of the reed, or everything of the above at the same time. 3D printing is anisotropic and some features need to be printed along the layer to have proper durability/smoothness to work or you have to calculate this anisotropy in your design. Action is the most tricky part to 3D print (except for the bellows, which is straight up impossible). All Edward's levers go straight, some of them only have bridges around colliding buttons. Edward uses special carbon fiber infused filament to ensure enough durability, as those bridges are weak spots because they are across layers.

[Chris Ghent]

On 1/4/2023 at 2:13 PM, David Barnert said:

 

This is true, but irrelevant. It is just as true that for any given dimension from corner to opposite corner the more sides you use the larger the square area of the end will be. It is only by arbitrary convention that we refer to the size of a concertina by the measurement across the flats rather than from corner to corner. Neither has any more intrinsic validity than the other. So if you compare the force necessary to move the bellows between a square concertina and a hexagonal concertina of the “same size,” you will get a different result depending on whether you define “same size” as across the flats or corner to corner.

As I specified “across the flats” because it led directly to my point rather than reaching for an “arbitrary convention”, any discussion of  point to point is unnecessary. As to “arbitrary” convention in using “across the flats”;  reference to “point to point” would be mathematically awkward during the planning process as well as confusing in the sales process and I doubt anyone has regularly, if ever, compared the size of concertinas in any way other than across the flats.  Having said that, a box maker would likely take note of it and it pays to be careful of it when selecting a blank for making pad boards, ends or reedpans.