Why Are Concertinas Hexagonal?

[Clive Thorne]

I'd always assumed that 6/8/12 sided was a compromise between the "Ideal" (I guess circular), and ease/cost of construction.

[David Barnert]

1 minute ago, Clive Thorne said:

I'd always assumed that 6/8/12 sided was a compromise between the "Ideal" (I guess circular), and ease/cost of construction.

 

Circular would roll off the table. More than 8 sides are in danger of doing likewise.

[RAc]

2 hours ago, Jnr Concertina said:

Speaking of shapes.....ever seen a three-sided concertina? Or a picture of one?

From my limited understanding, 3 sided would be about the worst of all possible worlds if you look at it from the "usuable vs.wasted space" perspective. Four seems to be ideal, everything above that degradingly worse.

[Clive Thorne]

On 8/16/2023 at 3:57 PM, David Barnert said:

 

Circular would roll off the table. More than 8 sides are in danger of doing likewise.

I mean't that circular would be ideal from the point of view of homogeneity of the bellows movement, and possibly even sound etc. Obviously round is impractical for the reasons you state.

[Wolf Molkentin]

3 hours ago, Clive Thorne said:

I mean't that circular would be ideal from the point of view of homogeneity of the bellows movement, and possibly even sound etc. Obviously round is impractical for the reasons you state.

however, I‘m not aware of any advantage in homogeneous bellows movement anyway 

[Little John]

I've been back through this debate, and one aspect that hasn't been mentioned is this. For a fixed measurement across the flats (which is probably the most important for perception of size) the square offers the most internal space; particularly for reed chambers but also bellows volume. The hexagon offers more internal space than the octagon and the circle is the worst possible configuration.

 

A second aspect is that the hexagon is an aesthetically pleasing shape and - for that reason alone - an obvious choice. Only @Anglo-Irishman touches on this when he says "The Germans, who originally built their concertinas rectangular, soon twigged that the Anglo-German, with its hex ends, just looked more classy, and began building their concertinas hexagonal, too."

[Wolf Molkentin]

… but given the choice of a radial arrangement it will be just the other way around I reckon:

 

the circle being the best option, and dodecagonal the next best thing (but still in danger to roll off the table), then octagonal (Æola) asf.

 

but I agree that hexagonal is most pleasing re aesthetics (and I prefer it when supporting the instrument with a knee/thigh as well, but for a personal reason, because a twist by 60 degrees is exactly what fits my approach)

[RAc]

34 minutes ago, Little John said:

 one aspect that hasn't been mentioned is this. For a fixed measurement across the flats (which is probably the most important for perception of size) the square offers the most internal space; particularly for reed chambers but also bellows volume. The hexagon offers more internal space than the octagon and the circle is the worst possible configuration.

 

 

Just for completeness (and vanity's 😉) sake: I did mention this earlier.

 

Nevertheless, I natorally agree, but to me, the octagon is the most pleasing shape. I suspect one logistic reason for a hexagon might be that hexagon shaped objects can very efficiently be stacked on top of each other (presupposing of course that all objects have the same object size), maybe the trucking lobby has had a say here... ?

[Little John]

46 minutes ago, RAc said:

Just for completeness (and vanity's 😉) sake: I did mention this earlier.

 

Indeed you did, Rüdiger! I apologise for missing it: " ... 3 sided would be about the worst of all possible worlds if you look at it from the "usuable vs.wasted space" perspective. Four seems to be ideal, everything above that degradingly worse." [My italics.]

[Steve Schulteis]

1 hour ago, Little John said:

I've been back through this debate, and one aspect that hasn't been mentioned is this. For a fixed measurement across the flats (which is probably the most important for perception of size)...

 

I disagree a bit on the perceived size. Having handled hexagonal and square concertinas of comparable distance across the the flats, I found the hexagon felt more compact, as the corners are less obtrusive. In mockups, I think the same is true for an octagon vs a hexagon. So at least for me, the shape makes a noteworthy difference as well.

[wunks]

You can, of course increase the usable space without increasing the "across the flats" measure by elongating two parallel sides as seen in some instruments in a lower register.  My 6 1/4" Jeffries has 51 buttons including air.  Stretching it by about an inch would allow 4 more spaces on each side handily extending both the lower range and the overlap.  Has anyone tried this with a small hex box?  I know the Harringtons are stretched in this way.

[RAc]

12 minutes ago, wunks said:

You can, of course increase the usable space without increasing the "across the flats" measure by elongating two parallel sides as seen in some instruments in a lower register.  My 6 1/4" Jeffries has 51 buttons including air.  Stretching it by about an inch would allow 4 more spaces on each side handily extending both the lower range and the overlap.  Has anyone tried this with a small hex box?  I know the Harringtons are stretched in this way.

true, but imho this is just a hair-splitting interpretation of "across the flats." In either case, "squaring out" (or rectangling out, in the case of asymmetric instruments) would yield the most usable space, wouldn't it? The bottlenecks that account for wasted space appear to be the triangular corner pieces! 

[Chris Ghent]

20 hours ago, Little John said:

I've been back through this debate, and one aspect that hasn't been mentioned is this. For a fixed measurement across the flats (which is probably the most important for perception of size) the square offers the most internal space; particularly for reed chambers but also bellows volume. The hexagon offers more internal space than the octagon and the circle is the worst possible configuration.

I’m surprised this has not been mentioned as it is an important point.  The more sides a concertina has the smaller the square area (when comparing concertinas with similar AF measurements). A smaller square area is important when trying to optimise response. I did the maths a long time ago and don’t have the results to hand but my recollection is a 6” octo is around 8% smaller than a 6” hexagon concertina.  As the number of sides gets larger the percentage decrease in sq area with each step diminishes and the amount of work increases and going beyond 8 sides seemed pointless. So a square might offer the most space but it is also the least efficient.  
 

When I say optimised response, I mean fast to speak, but also requiring the least effort. 

[alex_holden]

19 hours ago, wunks said:

You can, of course increase the usable space without increasing the "across the flats" measure by elongating two parallel sides as seen in some instruments in a lower register.  My 6 1/4" Jeffries has 51 buttons including air.  Stretching it by about an inch would allow 4 more spaces on each side handily extending both the lower range and the overlap.  Has anyone tried this with a small hex box?  I know the Harringtons are stretched in this way.

 

I tried this on paper once: it had some benefits in terms of reed pan and action lever layout, but the client preferred the visual aesthetic of a slightly larger regular hexagon.

[wunks]

I seem to recall a "strexagon" mini posted somewhere.  Were the reeds radial or parallel in the large Basses with this feature?

[Wolf Molkentin]

2 minutes ago, wunks said:

I seem to recall a "strexagon" mini posted somewhere.  Were the reeds radial or parallel in the large Basses with this feature?

Lachenal baritone ECs have a mix of radial and parallel reed chambers

 

Edited August 21, 2023 by Wolf Molkentin
typo

[Leah Velleman]

One advantage of a hexagon over a square is that if you're playing on your knee, it's easier to rotate the instrument a small amount to find a more comfortable angle. I find it pretty useful to turn it 1/12 turn away from me (from resting on a flat to standing on the adjacent corner), and I gather some people turn it a whole 1/6 turn. On a square instrument, the corners would be sharper, making 1/8 turn less comfortable, and 1/4 turn would be too much.

[Wolf Molkentin]

1 minute ago, Leah Velleman said:

One advantage of a hexagon over a square is that if you're playing on your knee, it's easier to rotate the instrument a small amount to find a more comfortable angle. I find it pretty useful to turn it 1/12 turn away from me (from resting on a flat to standing on the adjacent corner), and I gather some people turn it a whole 1/6 turn. On a square instrument, the corners would be sharper, making 1/8 turn less comfortable, and 1/4 turn would be too much.

indeed, as mentioned above, for me it’s 1/6 and not 1/4 or 1/8