Lost in a TRX4M build

[WickedFog]

I’d have to bring it home, son would want to see it

I was wondering if I was getting some kind of rfi from the new motor on it. It was strange, with both suspect servos, running on battery power, just the front would trip out. Swapped the front to a servo that ran at 6 volt through receiver, rear still at battery, rear started tripping out, front was fine. Both suspect servos now on receiver power and fine. The curiosity is gonna kill me

Another edit: I had used the Traxxas original steering servo for my high/low shift servo, i was wondering if maybe I was pulling too much but it didn’t matter with it hooked up or not

Yeah, it could have just been interference. That has been known to happen. Maybe running on battery power made the servos more susceptible to that.

 

[Weezel]

Just look up ohms law. I couldn't find a good picture depicting the relationship.

I=V/ R. Amps=Voltage/Resistance

Just take an amp reading on your servo at 6v and then at battery voltage

 

[Lostinthewoods86]

Now I’m really curious.

 

[WickedFog]

Just look up ohms law. I couldn't find a good picture depicting the relationship.

I=V/ R. Amps=Voltage/Resistance

Just take an amp reading on your servo at 6v and then at battery voltage

That's what I was getting at about it could be getting a brown out. With all those servos, it may be trying to draw more amps than the system can put out.

One thing I wonder about that - are your servo endpoints set correctly? If even your shift servo is not set correctly, and it's constantly drawing amps because it never stops trying to put force on the shift arm, that could be part of your problem. And that may explain why when you dropped back down to 6v on the steering servos the problem went away, because you gained a little headroom there. You'll also burn up your servos if your endpoints aren't set correctly because they are working too hard.

I am curious as well what this might be. So if you do bring the scope home, hopefully we get to follow along with your diagnosis

 

[Doom!]

Electronics stuff goes right over my head, I too am a bit curious.

 

[Weezel]

Me too! I want to follow along.

Plugged directly to battery is the confusion part. Lol.

Could there possibly be a ground loop issue when plugged directly.

 

[WickedFog]

Could there possibly be a ground loop issue when plugged directly.

That could very well be causing an interference I think.

The way his was plugged into the battery, it was just getting the power from that. Bypassing the BEC of the ESC. The signal wire still went to the Rx.

So far we have possible causes...
Wet Rx
Too many amps drawn by electronics
Radio Interference
Servo endpoints (especially shift servo)

I feel like I'm missing something. You live down there with all that Voodoo stuff. Maybe some jealous neighbor put a hex on your truck

 

[Weezel]

Uh oh!