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jtkirk01
08-26-2005, 04:32 PM
Hello all! I'm relatively new to RC airplanes and I recently purchased a BeginAir RTF (http://www.rcuniverse.com/buynow/keywordclick.cfm?bid_id=2643) kit from parkflyers.com. It is a very basic 4 channel plane. I recently lost the first one in a tree due to a control problem with the plane. Whenever I apply left or right aileron I lose power to the engine until the servo has extended fully. Other than that its fine. Does anyone have any ideas on what could cause a problem like that? My thanks for any assistance!
Glacier Girl
08-26-2005, 06:05 PM
It could be a voltage problem. Many of the systems have a low volt cut off. When battery volts get low, motor cuts off but allows controls to function for a short time. Possibly the servos are pulling volts down enough that the cut off is kicking in.
jtkirk01
08-26-2005, 08:21 PM
It could be a voltage problem. Many of the systems have a low volt cut off. When battery volts get low, motor cuts off but allows controls to function for a short time. Possibly the servos are pulling volts down enough that the cut off is kicking in.

Could be except it behaves the same across three different and fully charged batteries, one Lithium Polymer with a very long run time. I also suspected the receiver but was able to rule that out as well. Thank you for your reply though!
U2Steve
08-26-2005, 08:48 PM
It could be a voltage problem, indirectly:

You could have some control binding. If the servo can't move freely, the servo motor will draw more and more current in an attempt to move. (Of course, once it's reached the end of its travel, the motor shuts off- no more current draw.)

The excess draw from a stalled servo is enough to bring the battery voltage down to the point where the low-voltage cutoff in the speed control kicks in, shutting off the plane's motor. When you're not moving the servo, though, the battery will bounce back, voltage-wise, and the motor will run again.

Could be way off-base here, but it fits the facts. To check, just remove the control rod from the servo, and move the control surface by hand. There should be NO stiffness, resistance, or binding anywhere. If there is, bend, tweak, lubricate, re-hinge, or whatever it takes for things to move freely again.

Steve
jtkirk01
08-26-2005, 09:53 PM
Steve

Thanks you very much for that reply. It does really sounds like what is happening and I will check tonight to see if there is anything getting caught. Thinking about the servos for the ailerons I am pretty sure they are mounted on the wing itself and nothing between it and the foam could tangle it. Still, I'll go back over everything tonight.

Thanks again!
U2Steve
08-26-2005, 10:12 PM
If it's not the rods, it may just be the hinges themselves are too stiff. Are the aileron hinges made of tape, or are they just sort of stamped into the foam? Foam hinges can be loosenen by unhooking the control rod and flexing the aileron back and forth a few dozen times. Taped hinges might just have to be re-done, but that's easy enough.

Glad to help. We were all new pilots once.