I was running my T6.1 after replacing a receiver that just died. The truck now seems to randomly stop after a few min, like it is having a seizure No throttle and the wheels turn slowly on their own. A second later and everything is back to "normal". Sometimes the truck will take a second or 2 to get going if I have to come to a stop. I wonder if I am experiencing brown out and if that is what may have killed the previous newish receiver. This started happening after I changed motors from a Trackstar 10.5 to a Trackstar 9.5.

Thanks


Specs:

T6.1 temps < 130

Motor/Bat: Trackstar 9.5 / 5000mah 2S

Esc: Xerun V3.1 120A (should be good >5.5T)

Servo: Reedy 1206

Radio: spektrum dx5c/sr315

Swap the motors back or first try a different sensor cable, maybe a sensor problem in the motor or sensor wire....

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could be a bad connection inside battery... poor weld. ... been there, done that.

It could be the bec dying in the esc. Pull the red wire out of the esc connector that goes to the receiver. Then power the receiver with a receiver pack. If the problem goes away with the battery, the bec is likely the issue.

I've had a receiver go bad, and it took out 3 different esc's and a motor before I realized that the receiver was the problem. I had a bunch of different cars, and would move electronics around, so it took that receiver killing 2 esc's in two weekends before I figured out the receiver was the issue.

Could be anything, I agree with chuck, swap the battery first to see if problem persists, I have had to repair shotty soldering on LiPo packs in the past as well. It could be a bad sensor wire or possibly a bad sensor board on the motor, if battery swap doesn't fix the problem, then I would pull the sensor wire and run it in sensorless mode. I have seen guys at the track damage their sensor board on the very first battery pack after taking a nasty crash. I have made it a point to always check the gap between the rotor and sensor board on every new motor I buy to help prevent damaging a sensor board that may be too close.. I have seen some rotors that were actually rubbing on the sensor board! I like to have at least 0.1mm gap to play it safe. It will be pretty obvious if the sensor board is damaged when you pull it out, but there are sensor testers available fairly cheap:

If you think you might ever get into any stock racing classes then I would invest in a motor analyzer which not only helps you test your sensor, but offers a myriad of other features which can help you tune stock motors for peak performance, I use this analyzer here:
https://www.rcjuice.com/skyrc-brushl...r-checker.html

Thanks for the ideas. I swapped motors to a Trinity 13.5 and batteries this morning, I didn't try changing the sensor cable yet. I noticed that the power loss occurs If I am heavy on the throttle.
Power always comes back after a few seconds. Makes me think the receiver is loosing power. Perhaps the servo is a hog.

The internal BEC should be strong on a brand new HW v3.1??? I would like to avoid clipping wires for now. The receiver is brand new also.
The shop owner said that Spektrums may need a glitch buster cap in the receiver.

Also be sure to check you didn't lose your EPA settings, not sure how old your Spektrum radio is, but I recall a friend having an issue with his Spektrum where it would inadvertently reset his EPA back to 100% throw and he'd get brownouts because the servo was overloading when the EPA needed to be around 85% instead. Also be sure to set your end points with the front wheels on the ground.

Excellent advice. Ill have a chance to try these ideas tonight and report back.

Checked the servo at the track today. It was fine but the car was still acting up, especially after landing a jump.
I noticed the battery leads were being pulled out of the pack by the battery retainer. Re-positioning them seems to have helped.
Ill have to run a bit more to be sure. Im not a fan of the T6.1 tie down systems

I just read that internal temps will be different then whats really happening on the outside it could be your esc temp settings. cutoff or it could be bad batteries

Checking back in. I had to replace a receiver that went bad and the issues went away for a week and now the truck is acting up again
Im not sure if it is browing out or I am experiencing a glitch.

I found documentation on the HW xerun pro esc and you can adjust the bec from 6v to 7.4. Ill try doing that. Maybe the Reedy servo is power hungry.

Be sure the servo and receiver will work on 8.4v but I doubt it will give a solution.

You can better try a glitch buster. a simple short wired capacitor into one of the receiver free ports.

From what you describe (wheels turning slowly) my suspicion is this is not a brown-out issue and more than likely a BEC issue. The advice above to ensure your receiver is rated for the voltage you are running is spot-on, and you can also measure the voltage coming from the ESC to be sure. If it acts up long enough you can try to measure the voltage coming from the BEC at that time but it could be hard to catch.
One thing you could do to diagnose for sure is to run an external BEC. Just make sure you remove the power wire from the plug going into the receiver from the ESC, and then you can plug a BEC into any empty port on the receiver. The BEC simply needs to be wired directly to the battery wires and will provide the power to run your radio/servo.

I tried a glitch buster cap yesterday but it didnt stop the issue The day before, it ran fine without the glitchbuster. I noticed that keeping the truck below 3/4 throttle seems to prevent the condition.
I'm starting to believe it could be the servo. If it is a bec issue then can someone please tell me why raising the internal bec would not be the first choice over installing an external one. The receiver I am using can use 3.5-9.6V

What's the steering EPA set at?

Also curious if this only happens in far corners of the track with substantial distance, possibly a range issue? I've had range issues with Spektrum, also curious what voltage your Tx was at? Did this problem happen later in the day? Any chance it goes away with a fresh charge on the Tx pack?