Cardboard Conch Horn

por
Destacado
Conch shells make a grand sound as a horn, but several species of the the actual animal are endangered, harmed by being harvested for the souvenir industry.

This is my attempt to create a more sustainable version of the instrument.

Paso 1: Materials and tools

If you know my work, you know I like simple materials.

This is put together from corrugated card from an old box, duct tape, and a short piece of PVC pipe.

The only tools I used were a craft knife, my trusty Leatherman, and a hacksaw (to cut the pipe to length).

Paso 2: The parts

The whole thing is made from the flaps cut from a large cardboard box.

Two flaps duct-taped together made the main coil, and a third flap, cut in half, made the end-pieces.

Dimensions.

The flaps were 17cm wide, and when taped together they were just under a metre long.  For the sake of aesthetics, I made the end-pieces 17cm square as well.

The pipe, a scrap I found in a corner, was about 2½cm in diameter, and about 10cm long.

Paso 3: Curl it up

I needed the strip to spiral with ease.

To that end, I used the two flaps which had the corrugations at right-angles to the long dimension.  I dragged the strip hard over the corner of the table to force it into a curl, like quilling, writ large.

Paso 4: Fix the curve

Starting in the middle, I arranged the curled strip into a visually-appealing spiral.  There may be an optimum shape, but I don't know what it is.

I anchored the spiral in place with small pieces of duct tape.  Not pretty, but it worked.

Paso 5: The mouthpiece

The mouthpiece was made from a short piece of PVC pipe.

For comfort's sake, I used my knife to chamfer the edges of the pipe.

I cut a suitable hole in the middle of the second end-piece, and then anchored the mouthpiece in place with more duct tape, then fitted it in place and fixed with... duct tape.
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lugeperez
lugeperez dice: Jun 21, 2013. 8:01 AM
Hi, looks great, Ill try to build one for my home town parties, using it instead of the hard to find natural shells
Kiteman
Kiteman dice: Jun 21, 2013. 2:18 PM
Cool, post pictures or a video when you do!
Randomguy65
Randomguy65 dice: Ago 12, 2012. 8:34 PM
The magic Conch shell! (horn)
PKM
PKM dice: Ago 10, 2012. 6:20 AM
The ideal shape is almost certainly one of these: http://www.xaraxone.com/webxealot/workbook22/spirals_0.gif

The linear spiral has a constant cross-section so will act like a long tube, the exponential has an exponentially increasing cross section so will act like the bell of a horn (and replicates the proportions of an actual seashell). I made something similar to amplify the rear-facing speaker on my phone so I can hear the speakerphone when it's in the cradle.

If you find (or make) a couple of sliding-fit cardboard tubes will we see Roger-X playing the cardboard trombone?
Kiteman
Kiteman dice: Ago 10, 2012. 2:02 PM
Right now, I don't *which* spiral I make, I just want to make a spiral.

(Is there free 3d modelling software that will take pencil scribblings and vague gestures as input?)

stringstretcher
stringstretcher dice: Oct 11, 2012. 6:56 AM
Inkscape will make you a nice spiral. You can then output it to another format like dxf for your CAD prg. Neat shell. It will work better if you can make it a tight seal along the edges of the spiral. No leak means a long tube, and that will play MUCH better.
rimar2000
rimar2000 dice: Ago 10, 2012. 5:37 AM
What is the name of that beautiful musical piece?
caitlinsdad
caitlinsdad dice: Ago 9, 2012. 7:48 PM
You made a snail shell not a conch shell. It is visually appealing because of the "Golden Mean".
Kiteman
Kiteman dice: Ago 9, 2012. 8:26 PM
A conch <em>is</em> a snail (isn't it?), just a really big one.
caitlinsdad
caitlinsdad dice: Ago 9, 2012. 8:41 PM
I think you need to use Autodesk software to properly model one. :P
Kiteman
Kiteman dice: Ago 9, 2012. 8:49 PM
I spent an hour this morning, failing to draw a spiral in 123D...
caitlinsdad
caitlinsdad dice: Ago 9, 2012. 9:41 PM
There's gotta be a squiggly curve line generator in there somewhere. Then you have to stretch the walls up in 3D along some curving axis. I loaded that up, crashes a lot, and big learning curve. I don't think it is really endeared to artists and turns an enjoyable creative experience into a frustrating one.
Kiteman
Kiteman dice: Ago 9, 2012. 9:52 PM
If there is, I can't find it. Maybe it's not touch-pad friendly, or maybe I just haven't played enough video games...
Kozz
Kozz dice: Ago 10, 2012. 8:04 AM
Don't take me as a "hater" for this... I think I'd say that the spiral is indeed visually appealing in spite of the fact that it does not follow the "Golden Mean" or logarithmic spiral. http://www.sciencenews.org/view/generic/id/6030/title/Sea_Shell_Spirals Fascinating bit of math there if you're interested. I mention this article to correct a very common misconception. :)
caitlinsdad
caitlinsdad dice: Ago 11, 2012. 9:26 AM
Hmmm, less is more, form follows function, beauty is in the eye of the beholder...
iceng
iceng dice: Ago 9, 2012. 5:51 PM
That vid put me back to a trip in the Bhamas :-)
Kiteman
Kiteman dice: Ago 9, 2012. 6:06 PM
Trust me, with the right mouthpiece, it sounds a *lot* nicer!