Search found 21 matches

by Cita
Sat Feb 25, 2006 8:37 am
Forum: Ramjet forum
Topic: cheap ramjet
Replies: 5
Views: 4685

re: cheap ramjet

No problem in starting with propane.
Very good combustion.
The sudden expansion chamber was working beyond expectation.
By far the best ramjet I ever made.

Cita
by Cita
Fri Feb 24, 2006 2:54 pm
Forum: Off topic forum
Topic: Backpack helicopter
Replies: 63
Views: 24259

re: Backpack helicopter

Thanks, The rotorhead in the picture is not complete,there must be two more bevel gears between the two on the rotors. Both engines will drive the lower rotor and the gears will change direction of rotation for the upper rotor. The co-axial GEN Japanese helicopter uses different rotor RPM to control...
by Cita
Fri Feb 24, 2006 8:33 am
Forum: Ramjet forum
Topic: cheap ramjet
Replies: 5
Views: 4685

cheap ramjet

ramjet made of car fire exthinghuisher steel bottle. Unscrew valve at top of bottle and remove powder. Drill 50 mm diameter hole in bottom of bottle with circular saw. Get stainless steel kitchen sink retainer and grind out circular part with holes.This will give you a cone with a flange. Adjust out...
by Cita
Fri Feb 24, 2006 6:25 am
Forum: Off topic forum
Topic: Backpack helicopter
Replies: 63
Views: 24259

re: Backpack helicopter

I'm not using Rotax,the Austrian guy is.
I don't know what fuel he uses.
He would be happy with 36 hp I guess.

Cita
by Cita
Thu Feb 23, 2006 10:50 pm
Forum: Off topic forum
Topic: Backpack helicopter
Replies: 63
Views: 24259

re: Backpack helicopter

Rotax 125cc water cooled kart engine-28hp Apparently there are cooling problems so the blue container is probably water. Power is seemingly marginal but being filmed i Austria I dont know at what altitude this test was. Could well be that at sea levell or on a cold winter day the power is just suffi...
by Cita
Thu Feb 23, 2006 9:12 pm
Forum: Off topic forum
Topic: Backpack helicopter
Replies: 63
Views: 24259

re: Backpack helicopter

The designer/builder is not German but Austrian,Franz Schoeffman. The "gearbox" is located between the two rotors (IVO Ultra light propellers). It are just 4 conical gears not unlike the car differential setup. The lower rotor is driven via chain and sprocket,the conical gears reverse thu upper dire...