Hi all, I hope the following will answer some of your questions.
From my book ...

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The Design

This project was inspired by all the ones that dogged me over the
years.  You know the ones I mean ... Weld the ____ bore out the ___
secure a ____ from an old farm tractor.

I wanted to build and document a project that was fun to make and
timeless.  The main goal was to design the project so the plans would
be useful well into the future.  I also wanted to use parts that could
be found in most parts of the world.  It would also be nice to be able
to build the whole thing using only several hand tools and a drill
press, belt sander and a scroll saw.  I built my barrel organ around
one that was over a hundred years old.  My first hurdle was obtaining
reeds to make the sound.  After pricing accordion reeds and finding out
how difficult they were to obtain I almost scrapped the project.

While I was in a small music shop I saw a display case with different
types of harmonicas in it.  The owner of the store looked dazed when I
asked if a harmonica could be taken apart.  The man didn't care about
what was inside the harmonica and he did not want to sell me one
either.  After I promised not to bring the harmonica back after opening
it up he sold one to me.  The model he sold me had twelve holes and it
was only seven dollars.

I took it home and pulled it apart.  Inside I found two brass plates
with reeds mounted in them.  I didn't know how to play a harmonica
so I went back to the music store for a book.  I decided to get the
Ten-Hole Key of C harmonica that the book recommended.  Using a
ten-hole harmonica cut down on the number of parts required for the
project.  In my first design I put the plates side by side.  Then it
hit me to overlap them as you will see in the final design.  This
allowed all twenty plungers to be spaced evenly in a row.

The second hurdle was the bellows assembly.  Leather is just too
expensive and hard to find.  Added to the cost was a minimum order of
several square yards.  I tried rubber and vinyl only to find glue would
not stick to them very well.  Not to mention that what would stick to
the rubber or vinyl would not stick to the PVC.  One day while I was at
the library I found a book on organ repair.  The words Cloth and Rubber
Paint jumped off the page at me.  I then decided to use Sports Cloth
coated with Latex paint.  The test bellows became an instant success.
It wasn't until the final months of the project that the Sports Cloth
was scrapped.  While trying to get more sound from the organ the
bellows unfolded the wrong way from the air pressure.

After many test bellows I finally went with canvas coated on one side
with paint while the other is coated with silicone rubber.  The paint
helps the canvas hold the folds while the silicone makes it airtight.
Well now I had air and sound but an overall design was still needed.
My neighbor had just built two doll houses in an unique way.  He built
each floor separately and then he stacked them.  It then hit me to
build my organ using his method.  Any design error that might occur
would be confined to one level.

The drive system in a real barrel organ is accomplished with the use of
gears.  A worm gear plus a large circular one is used.  I know how to
cut gears.  Expecting you to cut gears is unfair.  The project uses
pulleys with leather shoelaces as drive belts.  Rubber O-rings can also
be used if you can locate them.  The last problem was the barrel.  It
looked very bad for awhile when trying to make a large drum.  Years ago
I made a spinning drum FAX machine with a piece of PVC pipe turned on
my lathe.

A lathe is becoming a very expensive tool these days.  To expect
someone to locate a lathe just for this project is unreasonable.  Years
ago I worked with mechanical timers.  They used pins on discs to turn
switches on and off that controlled power.  Building on this idea
spawned a drum that can be made with simple tools.  The use of staples
gave me the proper material for creating the pins.  The staples are
tempered steel but they still can be shaped.  The fact that staples are
bar shaped makes pressing them into round holes easy.

John Kleinbauer
Kleinbauer@JUNO.COM