Pusher prop glider

[shoyn]

Hi all, have been facing problems with my pusher prop gliders recently. For my skysurfer, once i added the LED strips on the plane, the plane tends to roll left when the motor runs, I have a feeling that the LED strip that is running across the top front of the wing is the culprit. While my other plane, eaglewing, tends to also roll left. I noticed the wing tip on the right side of the plane is bent up more than the wing tip on the left side of the plane. Anyone faced these problems before?

[shoyn]

One more thing i noticed, both planes when gliding without power, cannot turn by only using aileron, I have couple the aileron with rudder to make it turn.

[Deedubya]

The turn to the left under power is a normal occurrence in all planes with right hand props due to, depending on who you ask, p factor, torque, gyroscopic procession and/or the spiral slipstream. The aerodynamicists out there can explain this better than I ( and confuse the heck out of you with their arguments- I don't think this whole idea of exactly what's going on when things fly is completely sorted yet) but just know that a force exists, especially at high angles of attack, that wants to turn your plane left. Can counter this with a rightward (and downward, to reduce relative AOA of prop blades) thrust angle and readiness with the rudder stick. Watch a taildragger light plane take off and see the kicks of right rudder needed to keep it straight.

Here's a thread regarding this:http://www.rcgroups.com/forums/showthread.php?t=970004

[shoyn]

Thank you for the link. But the last time i flew these two planes, both planes do not tend to turn in any direction when gliding.

[Deedubya]

Sorry, perhaps I misunderstood. You said the planes tend to roll left under power. That's the common effect I was describing.


Check to make sure that the right wing tip is not twisted up. This is called wash-in. You should correct this and try to get both tips the same. I'm not familiar with these planes but perhaps hot water and opposite twisting should help. The right wing tip having wash-in will definitely cause plane to roll left. Worse, this condition can easily cause a tip stall, which will dump the plane suddenly to the right. This will happen when you're low and slow and a crash will be the result.

[Sunstorm]

Thank you for the link. But the last time i flew these two planes, both planes do not tend to turn in any direction when gliding.

This might also mean that the left wing is heavier than the right?

[shoyn]

Sorry, perhaps I misunderstood. You said the planes tend to roll left under power. That's the common effect I was describing.


Check to make sure that the right wing tip is not twisted up. This is called wash-in. You should correct this and try to get both tips the same. I'm not familiar with these planes but perhaps hot water and opposite twisting should help. The right wing tip having wash-in will definitely cause plane to roll left. Worse, this condition can easily cause a tip stall, which will dump the plane suddenly to the right. This will happen when you're low and slow and a crash will be the result.

How do you know that both tips are the same? I think this could be the problem i am facing.

[Deedubya]

Eyeball it.
Can use an incidence meter, even an IPhone app, but you can just eyeball both sides and get the wings with no warps. Nice true and equal.