ORIGINAL: naswifty
ORIGINAL: nitrobeast
Hey guys
I'm using a magnum 70 with a 13x6 prop.
I have to go full throttle for this thing to hover and eventually it doesnt have enought power and tips over.
I was wondering what prop size other guys are using with the same engine? The engine is still on the rich side but puts out 9100 rpm.
My cg was between 4 and 4 1/2. I just moved it to almost 5. Will this help? Will moving the cg back also help knife edges?
I'm using a 14x4 on my Saito .72 with no problems at all.
Sounds like the engine might be leaning out when vertical. Try taking the plane (without wing) and warming it up- then hold it (or have a freind hold it) and simulate the condition. if it starts to loose RPM, try richening or leaning the carb to full power when in vert mode.
4.75 to 5.25 for CG., and yes and no for knife edge. CG only applies to balance when dealing with lift produced by wing. in a knife edge attitude, the only lift generating part of the aircraft is the fusalage, so horsepower and rudder deflection are the ingrediants necessary to pull off the manuever. If your plane is tail heavy, the back will naturaly drop down, but it takes more HP to keep the plane in the "edge"- the tendancy for the plane would be for it to loose horizantal speed and begin to climb. . .
Hope that helps a bit. . . .
Jeff
Jeff
Thanks for the info. I'll be at the field today, leaving work early to go fly
. I will let you know how it goes.
Rui