DX7 – AR7000: problem of transmission

[enry74hh]

I’d like to have your suggestions about the problem I’m having with my helicopter.

3DX500SE
DX7 – AR7000
Motor Haker A30XL – Kontronik 80-6-18 with BEC – 4S 3700
N° 3 Multiplex PoloDigi
GY401 – S9254

While the model is working there are some interferences on the servos of the Swashplate and alternated switching off of the orange Leds on both receiving modules Spektrum.

When happens that both modules switch off, there is a temporary black out of the radio system with the consequent switching off of the motor.

I did several tests; such interferences seem to be caused by electrostatic charges generated by the belt. Spraying some antistatic liquid seems to attenuate temporally the problem.

During a test in which the external receiver was near to the tail-pipe (5 mm far) I noticed that in correspondence of the switching off of the orange LED came out some little sparks between the antenna and the tail-pipe itself.

I replaced the motor, Esc, Servos; I’ve changed the position of all components: the problem still happens.

I obtained a big improvement connecting the negative pole with the tail-pipe; with this modification seems that the switching off don’t happen but still there are some interferences on the servos that show themselves with quick and random blows.

I don’t know what else try to make safer the model and that’s why I need your help

I add that before to use the DX7 and AR7000 I had Futaba FF9 and R149Dp.
Also with the Futaba I had the same problems of interferences but never the switching off of the system.

Thanks
Enrico.

[jeffk]

That is definitely NOT normal behavior. First thing I'd do is contact Horizon Hobby and tell them what you're experiencing. They will likely want you to send the reciever back. You might also try relocating the receiver farther away from the belt.

How tight are you running your belt? I wonder if changing the tension may not have an effect on the static you're getting. I might also try a diluted solution of fabric softener on it (which contains anti-static ingredients), but only as an experiment, because I have no idea if it would deteriorate the belt.

[capebob]

The lights switching on and off on your receiver is an indication of a low or intermittent power condition. When the power to the receiver drops significantly below ~3.7 volts the receiver switches off. With the receiver now off it now sees more than 3.7 volts and it re-boots. I suspect that the BEC on your ESC is either malfunctioning or your are drawing more current than it is capable of delivering.

If you cannot resolve this issue you will have to check with the Italian distributor of Spektrum products. I don't believe Horizon Hobby will help.

Bob

[enry74hh]

The lights switching on and off on your receiver is an indication of a low or intermittent power condition. When the power to the receiver drops significantly below ~3.7 volts the receiver switches off. With the receiver now off it now sees more than 3.7 volts and it re-boots. I suspect that the BEC on your ESC is either malfunctioning or your are drawing more current than it is capable of delivering.

If you cannot resolve this issue you will have to check with the Italian distributor of Spektrum products. I don't believe Horizon Hobby will help.

Bob


It should not be a power problem because I have done tests with separate power supply (5 cell NiMh 1.2V); The problems remain.

Thank you for the answers.

[enry74hh]

That is definitely NOT normal behavior. First thing I'd do is contact Horizon Hobby and tell them what you're experiencing. They will likely want you to send the reciever back. You might also try relocating the receiver farther away from the belt.

How tight are you running your belt? I wonder if changing the tension may not have an effect on the static you're getting. I might also try a diluted solution of fabric softener on it (which contains anti-static ingredients), but only as an experiment, because I have no idea if it would deteriorate the belt.

I contacted via email Horizon; Still no answer.

[enry74hh]

To be fair to Spektrum on my Mini Titan no problem. (Dx7 and Ar6200).
One question: according to you is dangerous to fly with the tail pipe connected to the negative pole.

[Pinecone]

No, hooking the tail boom and other parts to the negative on the battery is not dangerous, and can help with static discharge problems.

If you are generating that much static, I think the belt may be rubbing somewhere, turning the tail into a Van de Graaf generator.