Electric control ...

I decided to make the organ electrically operated -- switches on the keys operate electric valves ("magnets") in the wind chest. This decision was prompted by 3 things:

1) The mechanical nightmare of a tracker (all mechanical) keyboard looked too daunting -- as did the plumbing nightmare of running hoses from the valves to the pipes. I wanted an artistic arrangement of pipes -- tall on both ends and short in the middle.

2) I play the organ, but not very well. I wanted to be able to insert a MIDI receiver and driver board between the keyboard and the pipes, so that I could link it to my computer and play MIDI files, record my friends playing, etc.

3) I can add another rank of pipes later. I have a full 61-note rank of flute d'amour pipes that some day I may hook up.

Keyboard Switches

The first part of the electric control is mounting the switches. Here, again, I had a stroke of good fortune. A local surplus-electronics vendor had a sufficient quantity of computer-keyboard switches that fitted my requirements: they were smooth-operating, had few moving parts (like ONE -- two, if you count the spring); and would over-travel after operating the switch. This last feature was important to me, as I wanted the note to sound just before the key hit bottom.


Close-up of the keys showing the return-springs and the switches. In another picture on this page, I show the switches wired to the diode matrix board.

 


The switches are computer-keyboard magnetic reed switches. They were cheap, and promised to be reliable, but, unfortunately, they were just a little bit too wide to fit on the half-inch centers of the keyboard.

 

So... I clamped them in the mill ...

... and took a little off both sides of each switch.


The switches were then glued in place in the switch rail.

Here's what it looks like with the switch rail in place. This photo taken during the final assembly.

The switches are wired to the diode matrix board (which is connected to the encoder with a ribbon cable -- not pictured here)

The maker of the board intended that I use CONNECTORS for the key switch wires. Instead, I chose to solder the wires directly. Cable is laced together with beeswaxed linen lacing twine.

The keyboard diode matrix is wired to the encoder board with a ribbon cable. For the magnets in the wind chests, I used a DB15 connector and a standard computer VGA monitor cable. It took 2 for the big windchest and one DB9 for each of the small windchests. The cables were cut and terminated as shown in the right-hand photo above, and put under the driver-board's screw terminals.

Look in the left-hand photo above. I had forgotten to cut a passageway for the wires to get from the console to the base. The photos below show me cutting that passage in the keyboard.

The console here is tipped on its back to show 1) the two air passages (with the white insides); 2) the DB9 connectors to the small windchests, and 3) the passageway discussed above.

Return to home page