The building of pipe organs results from hundreds of years of analysis
and experiment from people that have spent lifetimes tuning the art.
What I'm describing here is based on my very limited skill set and
I don't mean to offend anyone by my somewhat crude implementation.

Last fall, while I was working on my antique car and community
band projects, my wife sarcastically commented that I needed a hobby.
At that instant I was fiddling with a single wooden pipe I'd bought in
an antique shop and I equally offhandedly replied, "Okay, I'll build
a pipe organ."

eBay had a good offering of pipes and solenoid valves and it looked
like I could find a decoder; I knew a bit about MIDI, so why not.
I bought some pipes and valves and using the old deck wood from my car
trailer I made sort of a toe board and an air box.  After some research
it seemed that the Hut Electronics MIDI decoder would drive the magnets.

The big challenge was air.  I bought a bunch of fans, even a leaf blower,
before I read here about the Ametek blowers.  The first one I bought
was 240-volts, cheap, and it looked like it would work.  I made a box
for the blower, jury-rigged a relief valve and using some clear plastic
hose I made a manometer.  We connected the blower to the 240v clothes
dryer electrical connection and blew the first tunes through it a month
or so later, about Thanksgiving.

The organ was in the garage where it was about 30 degrees and all out
of tune, but sounded so cool I went back to eBay for more pipes and
magnets and added some bass pipes.  It was a little trickier making both
4 and 10 inches of water pressure, but I finally worked it out by using
two reservoirs with an adjustable baffle between them and another of
the toilet gasket relief valves.  I splurged on a 110-volt Ametek fan
with the remote control feature to replace the 240V job and tried
again.  Certainly the bass pipes added a lot.

We tried a bunch of MIDI files from the 'Net and my son and I decided
it needed bells.  The magnets from door bells are made to strike bells
so I figured they would make a glock ring.  I bought all the mechanical
doorbells available in our Home Depot, a dozen in all, and a set of
bells from eBay.  The problem was the doorbell magnets needed more
current than my MIDI decoder could handle, so after a few false starts
I made my own driver boards that could drive the magnets.  We found a big
TV cabinet at a local used furniture store and we mounted it all up.

The biggest problem we have is the air heats up about fifteen
degrees in a half hour of running and makes it hard to keep in tune.
As I said, it's a bit crude and out of tune but it is a huge source of
entertainment, especially playing calliope pieces with short notes.
Now I have to figure out how to get it out of the basement.  I hope you
can excuse the tuning problems enough to enjoy it at the link below.

  http://www.youtube.com/watch?v=csI2VcpNnOA 

Bill Clark