Building a Disk Turbine
The new compressor stator with the disks and backplate.
|May 1, 2003
I made a mistake yesterday milling the stator -- I measured the annular space at 2-3/4" rather than 3" in diameter, and didn't catch the error until I had completely milled the scrolls. I hadn't dimensioned my drawing in my hurry to start cutting metal. The problem was obvious when I assembled the turbine.
Trying to mill the space wider and then re-cut the scrolls didn't work out, and I decided to cast another stator. This time the charcoal furnace did its job, and I had a new casting in about an hour and a half from when I started packing sand.
I've become pretty fast with a single casting. I light the fire before starting to mold, and by the time I've put the flask together the coals are glowing. It takes about 20 minutes to melt a good potfull of aluminum, and about a half hour for the casting to cool before breaking open the mold.
This time the layout was good, and I had milled out a second stator by the end of the day. It looked nice -- fun seeing something that was just a part of your imagination emerge with its own sophistication of form from primitive equipment.
The turbine has an unexpected mandala-like look about it that's aesthetically satisfying. Don't know if it will work well, but it will be fun to find out.
(c) Copyright 2003, Stephen Redmond, all rights reserved
I got the idea for a multiple scroll housing from one of Kurt Schreckling's first turbine experiments. His engine looked quite different than mine -- it had a four-scroll housing made out of a big square of plywood. Channels were routed into the plywood about a half inch wide. They extended out to the corners of the board, which was why a square had fit the purpose. Tube elbows behind the scroll transferred the compressed air to a separate combustion chamber, which, in the photo I have, looks to be a spray paint can. The whole thing had the appearance of a gothic rocket booster from one of the old Buster Crabb Buck Rogers adventure movies. Very cool.
My scrolls are twelve in number and a quarter inch wide. They pass through the backing plate. I expect to add a canister housing to the back of the turbine to enclose a combustion chamber and an axial turbine. That's if the compressor actually works well enough to support them.
(01/05/04 I had to put the Tesla project aside while I built a new house. I expect to resume work on the project in Feb or March of 2004).