Hey all,

Referring to my e-truggy (Losi 8ight-t 2.0-e) running Castle 2200kV motor/esc, 4S Lipo.

Last year, running Traxxas RTR Rx/Tx. No issues all race season.

This year, upgrade to Airtronics MK-V with Waterproof Rx. I ran a few quallies, no issues, but now I have a problem. The system "browns out" constantly! I can typically control my throttle, but steering is gonzo. Unsure of the servo, it's not branded (bought the truck used) but it looks/sounds just like my Savox in my buggy.

Ran a capacitor, no help. Do I need to run a BEC with this setup?

Odd thing is... I raced (and won) several quallies, and a main with this setup, then all of a sudden, issues...

Thoughts?

Sounds like the ESC's BEC circuit has or is failing. Try an external rx pack or BEC to isolate it.

Will do! Thanks for the quick response!

What I did is rig up a small amp meter with servo connectors so I can bench test servo draw and voltage from an ESC, a weak BEC circuit and you can see the voltage sag when the servo is at full lock, was surprised how much Castle ESC's seem to sag under load.

I would try a known good servo as well as that may be the problem at hand. And with Castle Link now, you can set the the BEC voltage up to 7.4V if desired.
But since a capacitor is basically an electrical component that stores energy and didnt change anything, I would be leery that an external BEC would do anything also.

A Capacitor can't store a current if it's not of an adequate level to store in the first place. Also BEC Voltage is one thing but it's amp draw that causes brown outs.

Well I picked up a Castle BEC today, hooked it up (checked, the green LED is lit) and still nothing...

The motor works 100% -- The steering, not so much. It works very little, then craps out entirely.

Tried a different servo, same deal.

Went back to my Traxxas RTR Tx/Rx that I ran all last summer (the EXACT same setup that I ran last year for 4 months with no issues) and still the same problem.

Scratching my head at this point... Is my ESC somehow just not sending enough voltage to the Rx? I suppose I could try hooking up another ESC to test, but I don't have one with me at the moment.

Any other thoughts/suggestions?

Disconnect the ESC entirely and run just the steering servo using the castle BEC (you did disconnect the red wire from the esc to Rx didn't you before running the external bec???) and check again. If that doesn't work then god knows! Castle ESC's aren't renowned for having a particularly good/stable BEC supply. I have the XL2 in my Baja 5sc and the internal BEC is crap and so I am using an external BEC on that setup.

Personally I think you may have left the red rx wire from the ESC connected to the receiver as thats the only way the esc would still be in the receiver/servo power circuit and could be influencing the system. You must disconnect this wire when using the external BEC, if you don't you stand a chance of damaging the ESC as well.

try another radio. I had my transmitter cause glitching. replaced and all good.