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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Larry Renger on June 11, 2014, 07:02:39 PM
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As noted in another thread, a left hand prop solved my line tension problems in outside overhead maneuvers. The torque driving the prop should be causing problems, not solutions. What am I missing? ::)
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As noted in another thread, a left hand prop solved my line tension problems in outside overhead maneuvers. The torque driving the prop should be causing problems, not solutions. What am I missing? ::)
It yaws nose-out on outside maneuvers instead of nose-in. First time I saw an electric with a backwards prop, I was startled to see it do that in the hourglass, they look completely different than regular direction motors.
Brett
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Hi Larry,
Spiral airflow. It's the 900 lb gorilla among the prop-related asymmetries that plague our ships.
Every time the governor "throttles up" or the airspeed drops under near constant RPM conditions, it kicks the tail inboard with a pusher prop.
take care,
Dean P.
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I aways got better trim and cleaner flights with CW prop (right hand, tractor) then CCW prop (pusher) ... I mean ususal airplane - left flying, with thrust line over the wing and landing gears down :- ))) ... and it is also theoretically better compatible
yes it solves mentioned troubles, but they should be solved other way by usual trimming methods
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Is this not an effect of P-Factor?
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P-factor is the yaw induced by the plane flying at a high angle of attack. The effective pitch on the blades becomes different on the two sides. On a flapped model, the fuselage pretty much tracks true through the turn while the flaps provide the angle of attack.
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Is this not an effect of P-Factor?
Hi Ryan,
Spiral airflow has much more effect to our flying, when it comes to line tension issues.
There is more P-factor in level flight due to out-thrust and flying yawed outward than there is during all but hard corners, with a flapped ship.
That's because flapped ships fly the rounds with the wing centerline almost tangential to the loop.
On the other hand, that constant out/right-thrust induced p-factor is trying to bend our motor shafts into a bow, all the time.
The bow is canopy-ward or wheels-ward depending upon the rotation.
Take a metal rod, bow it and make it rotate, and eventually it or the bearings supporting it will fail.
Anybody out there remember the old Pontiac Tempest with Rope-Drive?
take care,
Dean Pappas
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P-factor is the yaw induced by the plane flying at a high angle of attack. The effective pitch on the blades becomes different on the two sides. On a flapped model, the fuselage pretty much tracks true through the turn while the flaps provide the angle of attack.
That is right, at AoA we fly (aproximately 10 degrees) and usual radius in corner, prop is aproximately tangent. However as Dean already wrote we have relative side wind and it makes moment pitching fuselage up (CW prop) and it adds to precession (both have the same direction). Fortunately we have landing gears drag and wing drag bot under thrust line, so that is reason why I thin CW prop is better compatible with models we use, so we not need to pull down all the flight.