E-flite Apprentice S

[ericrw]

Recently purchased a rtf and assembled a E-flite Apprentice S. When I connect up the battery it gives a musical note and then I place the model on level ground ( a table top); then the esc switch on the side of the fuselage is switched on, there are more musical notes and the servos work the A, R, E, as normal, as does the throttle. Then I get a continuous high pitch sound which does not seem normal. This sound does not go off, until I switch it off.

I contacted the retailer (a well known one) and by using the `phone he listened to the continuous sound . I was then told it was digital servos making the noise and that it is normal.

My fellow club member who has the same model does not have this problem. Any advise would be appreciated.

[Dave Hopkin]

Depends if the sound is coming from the ESC or not, if its from the ESC it sounds like its not sensing a signal from the RX

a) make sure the ESC is plugged into the RX with the correct polarity and is fully home and that none of the RX pins have been bent

b) Calibrate the ESC to the TX by powering down the model, power up the TX and push the throttle all the way forwards - power up the model (and switch on) count to 5 then move the throttle back to zero - power RX and Model down, power up the RX, power up the Model and it should be calibrated (if you are on Futaba you may have to reverse the throttle

If the noise comes from the servos, disconnect the all and plug one in at a time and see if its one thats causing the problem

[Denis Watkins]

Just to add, a continuous note is usually a "throttle high" warning, so trim down your throttle stick until it goes quiet.

Also, a continuous note can also indicate poor power supply, including low charged battery, under voltage, or poor connection

[Jonathan M]

Posted by Dave Hopkin on 13/09/2016 17:38:44:

Depends if the sound is coming from the ESC or not, if its from the ESC it sounds like its not sensing a signal from the RX

a) make sure the ESC is plugged into the RX with the correct polarity and is fully home and that none of the RX pins have been bent

b) Calibrate the ESC to the TX by powering down the model, power up the TX and push the throttle all the way forwards - power up the model (and switch on) count to 5 then move the throttle back to zero - power RX and Model down, power up the RX, power up the Model and it should be calibrated (if you are on Futaba you may have to reverse the throttle

If the noise comes from the servos, disconnect the all and plug one in at a time and see if its one thats causing the problem.

I have the same problem on my second-hand (I'd hardly call it pre-loved!) E-Flite Hurricane. Switching on emits a truly horrible sound.  Will try these troubleshooting methods.

Edited By Jonathan M on 13/09/2016 18:18:40

[ericrw]

Problem resolved ! I touched one of the servos and the noise stopped. Thanks for your responses. Eric.

[Jonathan M]

Eric - well done.

My own problems emanate from the ESC - the noise only stopped when I disconnected it from the throttle port on the Rx.

I tried calibrating the throttle as per Dave's method, and I also tried adjusting the throttle trim as per Denis' suggestion, but the problem persists.

I intend to scrap the foam Hurricane, so once I've extracted the electronics and motor for future use in another plane I'll be able to investigate the connections with more clarity.

[Dave Hopkin]

Posted by Jonathan M on 13/09/2016 20:18:30:

Eric - well done.

My own problems emanate from the ESC - the noise only stopped when I disconnected it from the throttle port on the Rx.

I tried calibrating the throttle as per Dave's method, and I also tried adjusting the throttle trim as per Denis' suggestion, but the problem persists.

I intend to scrap the foam Hurricane, so once I've extracted the electronics and motor for future use in another plane I'll be able to investigate the connections with more clarity.

Any noise would stop when you disconnect the ESC from the RX because the ESC powers and Rx and servos!!!

[Jonathan M]

Yes, but what I meant to say was that its the ESC or its connections that is the likely culprit: I unplugged it from the RX throttle port only after I'd already eliminated all the servos by unplugging them first.

[ericrw]

I think my basic problem was not knowing the different sound of a digital servo and that of an analogue servo. This is the first time I`ve used digital.