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A Question About Size!


guckey13

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:rolleyes:

Hi everyone,

 

I am posting this topic as a reserch topic. I am doing reserch on the size of concertinas. (There is a diagram below) If you would like to participate in this reserch base, just post these five (5) questions...

 

The Name and Model of your Concertina

The Number of Buttons on your Concertina

The Type of Concertina (English, Anglo, Duet)

The Three (3) sizes below (X inches, Y degrees, and Z inches)

And Your Name (if you want to post it)

 

Thanks alot for helping with this reserch!

 

Here is the diagram...

 

(you will probably need to click the thumbnail)

post-4-1063232900.jpg

Edited by guckey13
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It is not obvious whether by y you mean overall length of the concertina, in which case it is hard to measure meaningfully, or just the action box, and you would need to know metal or wooden end to decode this also. If just the action box, internal or external?

 

What's the research for..?

 

By the way, z=2x in a six sided figure.

 

Chris

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I suggest you think a little more about the geometry before asking for all these numbers.

 

E.g., if the end is a regular hexagon, the measure Z will *always* be twice X, and the angle Y will *always* be 120 degrees. If it's a regular polygon with other than 6 sides, the angle Y and the ratio between Z and X will again be fixed. E.g., The angle on an 8-sided instrument will be 135 degrees and that on a 12-sided instrument 150 degrees. (I'm in too much of a hurry to figure out those Z/X ratios at the moment.)

 

But some instruments -- mainly low ones like my contrabass -- are *irregular*, longer in one direction than in the other directions (sometimes referred to as "stretched"). For these you'll need more than one number for X or Z, and even the angles may differ, though they could still all be equal. On my contrabass the "long" Z (it *looks longer, but it isn't) is 11-3/8", while the other two Z's are 12". Angles are also different, but will have to wait, as I haven't seen my protractor in years, and though they could be calculated from the lengths, I don't have time to do the trigonometry right now.

 

By the way, it seems most common in the discussions I've seen to refer to the distance "across the flats" (from flat side to opposite flate side), rather than "across the points", which is your Z. But conversion isn't too hard. On a regular hexagon the "flats" measurement is .866 times the "points" measurement. The ratio can be calculated on other instruments, too; but later for that.

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E.g., if the end is a regular hexagon, the measure Z will *always* be twice X, and the angle Y will *always* be 120 degrees.  If it's a regular polygon with other than 6 sides, the angle Y and the ratio between Z and X will again be fixed.  E.g., The angle on an 8-sided instrument will be 135 degrees and that on a 12-sided instrument 150 degrees.  (I'm in too much of a hurry to figure out those Z/X ratios at the moment.)

 

... On a regular hexagon the "flats" measurement is .866 times the "points" measurement.

I'm so glad someone here has maintained their high-school geometry and trig skills ... I sure haven't!

 

I resolve to spend more time helping my daughter with her homework.

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I am doing reserch on the size of concertinas....

 

The Name and Model of your Concertina

The Number of Buttons on your Concertina

The Type of Concertina (English, Anglo, Duet)

The Three (3) sizes below (X inches, Y degrees, and Z inches)

It would be much easier and more standard to request the physical parameters as being dimension across the flats and number of sides.

 

Also - rather than posting answers to your guestions, I suggest using the

POLL feature this forum has so that things can be viewed and tallied easily. There are only a dozen makers or so (you could include an "other" as well), the number of buttons need not be exact but fall into standard ranges, and there are very few types and shapes of concertinas.

 

But for the record, my Wheatstone Hayden duet has 46 keys (buttons) and is a 6 1/4" hex.

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WOW!!!!

 

I didn't know there would be sooo many "correctional" responses. I was just tryng to find out a little information about concertinas, and everyones gotten irritated about it! And sorry about the "Bart Simpson" avatar. I thought it would bring a little humor to the fourm, but it dosn't represent whether or not I'm serious about my reserch!

 

I would like to say Thank You to those who did help me out. And If you would still like to post information i would appreciate it!

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Well, here are a few of measurements. 'Standard' hexagonal instruments seem generally to be 6-1/4" across the flats, give or take 1/8". That's true from the cheap 26-button brass-reeded mahogany Lachenal anglo and 48-button rosewood Englishes, to the 48-button Lachenal New Model English, to the 30-button Morse Ceilidh. The 48-button Rock Chidley English is 6-3/8", but that 'extra' 1/8" is just the thickness of the two layers of amboyna veneer on either side of the end.

 

The exceptions are the Jeffries, which with 38 buttons are only 6 inches across the flats... even the G/D.

 

My treble Æolas (8-sided) are 6-1/2" across the flats. The 55-button hexagonal duets -- both Triumph and MacCann -- are 6-5/8" across the flats.

 

As you see, I'm providing the measurements in the way that I'm used to dealing with them. And only one measurement. As I noted previously, that's all that's needed to compute what you've asked for.

 

I am curious, though, to what use you expect to put the information. Even if it's just to create a histogram/frequency table, you've missed asking for some critical information. Size vs. number of buttons? But a 48-button baritone English will almost certainly be much larger than a 48-button treble English, or even than a 64-button treble, and for good reasons.

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