My First Turbine Project
In the fall of 1997, I purchased Kurt Schreckling’s book on building Gas Turbine Engines for Model Aircraft. After reading this book three times over a 4-month period, I decided I would attempt to build this engine. Even after reading that book three times, my first engine was a failure, which I will explain later.
I had this compressor wheel, from an M&W Turbo-charger, lying around the shop, so I designed my engine around this wheel. It is of 3-inch diameter, so I made the turbine wheel 3 inch also.
The diffuser and shaft tunnel were made as per Kurt’s drawings. The shaft was made from tool steel and is solid not hollow. Bearings were 688. Short shaft has a square on one end so I would have something for tools hold on too. Oil was supplied through two 1/32 brass tubes 12 inches long wound around shaft tunnel, from a tank pressurized by case pressure, and metered through an IC engine remote needle value.
I started the combustion chamber, and could not find the correct tubing for the fuel nozzle. The project was put aside for about a year, until I stumbled across some 3/16 stainless tubing. I purchased a 20-foot piece for $7.95 , which I quickly loaded in my truck and left. I think it was suppose to be 7.95 A FOOT.
After cutting off a piece long enough for the fuel nozzle, I filled it with fine sand and heated with a cutting torch and wound it around a form not realizing the sand would turn too glass. With this set back, the project was put aside again for several months, until I was advised at a jet fly-in to purchase Thomas Kamps book. After reading his book, I decided to incorporate his combustion chamber. It was much simpler to build.
At this point is when I made the die to press the combustion chamber front. The case is made from a fuel filter that fits on my International Bulldozer.
The NGV is made from stainless steel pipe for in ID, and the vanes were cut from flat stock, as were the outer ring and the bolt flange. It is pictured on the number 2-engine case.
The intake cone was cut from a turbo-charger compressor housing, and fitted to a front cover machined from flat stock.
The assembled front end.
The fuel nozzles were made of 1/32 brass tubing, with an ID of .032.
After two failed attempts at starting on propane, I knew something wasn’t right. So back to Thomas’s book for more reading. His formula states that the diameter of the diffuser should be 1.7 times the compressor wheel. So back to the shop to start engine number 2.