rvnrcer

My Feedback: (4)

I crashed an EDF today. I have a JR 9303 and was using a Spektrum 7 channel receiver. I also had a separate 4.8 V battery for receiver. When I did a check of components after recovery, I found that when I powered up receiver with all servos still connected nothing responded. I disconnected all servos and connected a servo from my drawer and receiver worked fine. I then started reconnecting servo's from plane. They all worked until I hooked up retract servo. Receiver stopped working again. Servo had a bad spot in gear. Normally I would assume it happened in crash, but I believe either servo was too small or retract valve bound up. I lost control about the same time I retracted gear. Motor quit and control was lost. i assumed the ESC had shorted and blew out receiver. I now think this servo jammed and locked out receiver. I can't say servo didnt have bad gear when it was installed but I can say plane had flown before with no problems and gear servo was functioning properly. I did check all surfaces for correct throw and checked on high rates also. Since retract servo only moves a small amount and gear cycled I assumed it was OK. I hope this may save somebody else the same grief.

i have lost other planes with this receiver and was convinced it was low battery power. The servo in question was a Hitec.

Keith

rvnrcer

My Feedback: (4)

Forgot to mention that receiver pack tested to 5.2 volts after crash. I didn't use a switch harness and connected battery directly to receiver.

fizzwater2

My Feedback: (61)

did you measure the battery voltage with the jammed servo plugged in?

When a servo is jammed or stalled for whatever reason, it draws a tremendous amount of current, much more than it does in normal operation. Your battery voltage might be dragging down below the spektrum low voltage point with that servo plugged in, even without a switch.

I've known of jammed / shorted servo motors melt the insulation on wires - that's a lot of current..

rvnrcer

My Feedback: (4)

No i didn't measure voltage with jammed servo plugged in didn't think of it. I moved servo that was jammed from its jammed position and could feel bad spot in gear train with power off. I tried holding servo to re create situation and was unable to get receiver to lock up. i think Spektrum should look into this situation and make receivers that a jammed servo will be locked out instead of receiver locking out. Maybe this will help with the low voltage receiver lockout situation that Spektrum receivers seem to have.