The Blower, Regulator, etc.



Rear View of the base cabinet

The picture pretty well says it all. Clockwise from the left: :

  • 12 volt power supply -- This is a common, open-frame switching supply put in a box. 6 amps should be plenty of power. xxxxxruns:
  • Wind-pressure indicator -- Magnahelic gauge registers 0 - 6 inches of water. Organ is set to run on 4 inches.
  • The blower in a box. I had a stroke of good fortune -- I was able to find a blower at a surplus equipment vendor capable of a pressure of more than 6 inches of water. It is electronically controlled and relatively quiet. I enclosed it in a wooden box, lined with carpet as sound insulation. As the photo shows, it draws air in through an automotive air filter.
  • Hoses -- three black hoses are partly visible in this photo. The hose material came from Home Depot, and were originally intended for garden fountains. They are smooth on the inside. One hose connects the blower to the pressure regulator; the remaining two connect the regulator to the wind chests. The white plastic pipe is Home Depot, too. It's bathroom sink drain hardware.
  • Pressure regulator. This is simply an air box with a round hole in the top. A weighted hinged lid covers the hole. As the pressure increases sufficiently to lift the lid, it opens and the air escapes, thus regulating the pressure. The gray-colored brick provides sufficient weight to regulate the pressure at 4 inches of water. By loosening the clamp and sliding the brick left or right, the set-point pressure is adjustable. This design seems to work, but THE JURY IS STILL OUT on whether it is truly viable! Check back with me later and we'll see if I have to modify it as I get deeper into testing. .


Making the Pressure regulator


My aged circle-cutter was used to cut the hole for the regulator, and to mount the Magnahelic gauge.



First, pre-drill the 1/4 inch pilot hole and clamp the plywood to the table of the mill

Slowly cut the circle. I cut from both sides and met in the middle -- that way, there was tearout.

This tool makes me keep my hands in my pockets!!


Here I'm shaping the "lid" with the tool-post router


I know I got carried away here, using ball bearings where a cheaper bearing would do as well, but I had the bearings in the junkbox. That and a bit of 1/4 inch shaft and, presto!, I have the pivot for the valve.





Here you see the regulator assembled and in situ in the organ. Notice the red felt just visible under the valve "lid" (to insure a seal) and the paper shim under the hinge block (to adjust it perfectly level). The brick (painted with clear Varathane® to minimize particulation) is the pressure adjustment. Move it to the right, and it increases the pressure; to the left, decreases. The aluminum clamp locks it in place. THIS DESIGN HAS YET TO BE TESTED -- although it passed its initial functional test, but won't consider it a success until it performs well under all playing conditions.

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