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servos fluttering and motor starting on it's own????

keek

Junior Member
#1
so i was just bench testing a wing i built and after a few minutes of moving the servos i noticed that they started showing delayed reaction time, soon after that they started lagging and jittering, moments later the motor ran at full throttle and i didn't touch throttle through out the entire test! the prop was on and was just a few cm from me! luckily it didn't hit me....
I've got no idea why this happened but i'm guessing it might be my radios fault...
Nothing seems to be overheating, all the electronics are running quite cool and i don't think its interference from the esc and sbec because i moved the receiver well away from them and still went through the same scenario
Another thing i noticed was that when i move my right stick down and left (i fly mode 2) all the servos start jittering and even the motor speed starts to change too in a pulse like manner

Any idea what might be the problem? Is it my radio going bad or some other thing that's causing this?
Thanx in advanced!
 

colorex

Rotor Riot!
Mentor
#2
That sounds familiar to me, but only when I'm using my 72MHz transmitter - and it's turned off. Stuff starts to jitter and twitch. It happens when I turn off the radio, but also when I shake my radio a bit. I think it can be a faulty or loose cable inside the Tx (both in my and your case). I'd suspect it to be the PPM cable, it's one of the three cables going to the RF module.

What Tx/Rx do you have?
 

keek

Junior Member
#3
i've got a 4 channel 2.4 ghz system, i've opened up my tx and everything looks ok i cant spot any lose cables in there nothing heats up in there either..
 

colorex

Rotor Riot!
Mentor
#4
i've got a 4 channel 2.4 ghz system, i've opened up my tx and everything looks ok i cant spot any lose cables in there nothing heats up in there either..
Check the solder points for a cable going to the transmitting module.

The tx module is where the antenna goes in. It should be connected with 3 cables to the rest of the Tx board. One is positive, one is negative, one is signal. The signal cable might be bad inside (can't see it).

If you have intermediate electronics skills, try to check that cable, if not, ask someone to help out.
 

Ak Flyer

Fly the wings off
Mentor
#5
Unplug one servo at a time and see if the problem continues. Then try the esc. Eliminate each part of the system from the problem. It may be a component messing with you. Once you eliminate that....

have you checked the voltage at the receiver when this is happening? Make sure it's not a low power problem. If you have a servo drawing too much it may get to a point and start losing it's ability to communicate. What parts are you using? What type of servo's, how big, how many, how big is the esc?

Oh, and until you get it figured out take the prop off.
 

keek

Junior Member
#6
so i checked the system again this evening and my receiver is now acting funny it lights up for a second or 2 then switches off, i have no control of anything
I'm starting to think its the receiver thats causing all this
Checked the voltage in both the transmitter and receiver and they all look perfectly fine
I'm only using 2 9g servos and i'm even running a seperate sbec
the receiver doesnt seem to run without or with the sbec
i tried searching online for another receiver but couldnt seem to find the same brand receiver, am looking at the 9x now i wonder if it'll get here before summer ends?
 

Fensone

Master of the stock AXN
#7
Hello Keek, i believe your problem is the same wich i had once:

The only way out was to change Receiver and Transmitter, probably the thing you have to do too
 

keek

Junior Member
#9
Alright just ordered a new tx it's a hobbyking 6 channel radio cause i really dont have the patience to wait for a 9x right now, i've also bought some other goodies can't wait for the package to finally arrive!
Thanx guys for your help :)