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Got Jet Fuel? Turbine Helicopters > Poor College Student Manufactures a Turbine?
 
 
jrhelicopters
Heliman
Location: Fort Collins

Ok, So after seeing a Vario Jet Cat fly 1 year ago, I have not been able to think about anything else since. I have finally faced the facts that there is no freaking way I can afford one of these things till I am out of college, however I am pretty good at CNC machining and I own some manufacturing equipment so I was curious if it might be possible to make one for a cheap amount of money. <1000. I have seen many sights for kit turbines, but most of them are strictly designed for thrust, (afterburners and nozzles) not rotary motion. People keep telling me you have to hold tolerances of about .05 mm throughout the WHOLE engine to make one. Is this true? I mean, come on, that requires precision grinding not CNC milling. Also I heard Boeing tested one of there turbines by blowing up a couple of stator fans and it ran fine (for a while). My second question is this; one of the hardest parts for me to manufacture are going to be those compressor fans, has anyone ever thought of taking out those fans and using electic ducted fan motors to compress the air through the intakes. I realize you would then have to use the rear diffuser fans as your power source, but that would sure make this thing a lot easier to make....
10-04-2003 Over year old.
 
 
kauaison
Senior Heliman
Location: Alameda, CA

got some cool info here..

http://vzone.virgin.net/bigstuff.uk/bigstuffuk/mw54.htm

http://www.5bears.com/
10-04-2003 Over year old.
 
 
jrhelicopters
Heliman
Location: Fort Collins

Thanks

Thanks, I have certainly not seen that website before. This project is becoming more realistic....
10-05-2003 Over year old.
 
 
Twobeers
Key Veteran
Location: Toronto, Canada

The tighter you can get the tolerances in the combustion area (fan to case) the more efficient the engine will be in converting that burning fuel into raw power. As for making your own, the majority of home made turbines use the impellers from car engine turbochargers. Hope this gives you a hint in the right direction. As for Boing testing engines to explosion, this is normal in that business. When I was very young my old man was one of the chief engineer's for Pratt & Whitney in Boucherville, Quebec. There were many a Saturday or Sunday that he would take me in with him and the other engineers would let me loose at the controls to fire chicken & turkey carcass's into a jet or turbine engine. These tests are done to insure that the engine operates as specified, if one self destructs do to a bird strike they want to make sure that the fragments don't exit by going thru the casings. That would be almost certainly catostrophic in a aircraft if bits and pieces went flying thru the wings or fuselage.

I lost my infamous tag line.
10-05-2003 Over year old.
 
 
jrhelicopters
Heliman
Location: Fort Collins

So the combustion chamber is where I have to hold tight tolerances? That should not be too hard. I have heard of quite a few people using turbocharger parts, but I had wanted something I designed rather than some expensive retrofit thing that may or may not work. I have a very nice mill. It looks like I might need some lathe upgrades though.
10-05-2003 Over year old.
 
 
HeliPunk
Senior Heliman
Location: Arizona

Good Luck...

I bet you'll come up with something pretty soon. After seeing the talent you have from the custom parts you made for me, I bet you will pull it off.


Dave
10-05-2003 Over year old.
 
 
Doug
Elite Veteran
Location: Naples Florida....

Rather than reinventing the wheel do a little reading.
The first model size (non military) was built by Kirt Schrelckling in the 80's and had a bent sheetmetal nozzle and turbine and a Wood compressor (wrapped with Carbon) which limited RPM to about 75K and a thrust of about 4 lb later imprrovements by Thomas Kamps Raised that to about 10 LB All the parts to make them are readilly avalable. This book is some good reading as is the first one by Kirt. The biggest problem is the combustion liner and the internal clearances in the compressor are about .005"
Model Jet Engines
by Authors: Thomas Kamps , Keith Thomas
Released: 09 November, 1995
ISBN: 0951058991

I built a Phoenix 30.3 a couple of years ago and it is now a "conversation piece"

First member of Member of Bearings Anonymous
10-06-2003 Over year old.
 
 
jrhelicopters
Heliman
Location: Fort Collins

I will try that book out. How does your Phoenix run. That was one of my possible candidates.
10-06-2003 Over year old.
 
 
Gstjohn
Heliman
Location: Evans, CO

good luck
using blades out of a ducted fan is out of the question on a turbine whether it is r/c or real ( I own a Jet copter SX ) and also work on real turbines for Helicopters as my job, the blades in a ducted fan are to shallow of a pitch angle the blades on a turbine are very steep angle, almost like a boat prop. plus the ducted fan blades would not be able to handle the heat 500 degrees Celcius. yes you do have to hold that tight of tolerances throughout the turbine including the hot section. on some full size turbines the blades are actually loose fitting in the bearing housing so that when they get up to speed and up to temperature the metal will have expanded holding the blades tight and due to the expansion of metals will not crack the blades.

just a few more things to consider

Greg St. John, East Coast Vario, V-Blades Field Rep
10-07-2003 Over year old.
 
 
Doug
Elite Veteran
Location: Naples Florida....

Both of those books will give you a good understanding of compressors vs "fans". I have never run the engine as I did it for the experience and understanding. The Phoenix has design features that are way ahead of even the commercial units (how about a liquid cooled rear turbine bearing) and it runs at a low RPM (105K) 20LB thrust and PR of 3/1

First member of Member of Bearings Anonymous
10-07-2003 Over year old.
 
 
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Got Jet Fuel? Turbine Helicopters > Poor College Student Manufactures a Turbine?
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