Throttle jumps open when touched.
09-04-2003, 05:35 PM
#1
Thread Starter
Throttle jumps open when touched.
What causes the throttle to move when touched with a screwdriver? It never has a problem otherwise but If I try to adjust the low speed needle the throttle will quickly open halfway. I notice I used a metal clevis on the throttle which I will change. But what causes this?
09-04-2003, 06:49 PM
#2
My Feedback: (2)
Throttle jumps open when touched.
Is the throttle the only servo that jumps? Typically, metal on metal contact will cause rf noise and give you a hit. So if you're not carefull when inserting the screw driver it bangs around a little and you get hits on the receiver. You can test this by just tapping the engine or a metal motor mount and see if you get the hits, with the engine not running naturally. BUT, It doesnt always do that. Remember, rf is voodoo black majic. Your metal clevis is probably connected to a plastic arm on the carb so it shouldnt be an issue. Just make sure you have a locking nut behind it so it doesnt rattle around on the threaded control rod. Replacing it with a plastic clevis wouldnt be a bad idea, but will probably not solve your problem. Its just good setup practice, in my opinion. Then again, it may not be a problem at all if it only happens when you tap metal on metal. Just yesterday I was helping a student debug a radio problem with his plane. The elevator would intermittantly go to the end of its stop but return quickly. In this case we didnt see any rf interferance when tapping on the muffler. We DID fail a range check but only intermittantly with minor hits. Rerouting the antenna fixed that, appeared to be a separate issue. It looks now like it might be a defective servo since only the elevator appears to be affected. I still have aileron and rudder contoll when the hits start. Will be swapping the elevator and throttle servos to see if it follows to the throttle.
Edwin
Edwin
09-04-2003, 11:24 PM
#3
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Throttle jumps open when touched.
You're probably accidentally grounding (albiet high resistance) either that particular servo's signal line or something in the receiver itself that's causing that servo to be affected. You shouldn't mind it, as long as it's not caused by something in the helli itself. More than likley you're confusing the receivers perception of RF ground which will do all sorts of random things.
