Help pls! New AMP MT owner. Onyx/Kinexsis 4000kv ESC issues

[Guilleshop]

I upgraded my sons Amp to the Onyx 4000kv esc/motor combo. This I believe is identical to the Kinexsis 4000kv combo. Just a rebrand.
I also had to upgrade the Rx so purchased a Radiolink rc4gs. (Nice radio btw)

Because my 13 yr old will be running this rc, I’m sticking with Nimh. No lipo. Running 4200 6 cell Nimh.

Problem! We’re having a very unsettling issue where the car completely stalls, no steering no throttle, for about 5-6 seconds. This appears to happen more commonly after heavy extended throttle. Many times it occurs at close proximity so I am not thinking the transmitter or receiver is the problem.

I suspect the issue is with the ESC. Possibly the fact that I am running Nimh and not lipo. FYI, I know this is not the LVC kicking in, because I disabled LVC on the esc. (It wouldn’t even run properly with any of the low voltage options enabled... has to turn off to run nimh).

Has anyone successfully run this esc with nimh? I may have to buy a lipo to test out but I was really wanting to keep my kid away from lipo batteries.

This setup flies by the way! I added metal gear set too.

 

[Silverado86]

Most likely pulling too many amps and the NiMh can't provide power fast enough, time for a lipo, does your remote have throttle limiter so your kid can use it and grow into it?

 

[Guilleshop]

This is what I’m thinking too. I have a lipo 2S 5200 mah on order and will stress test against it tomorrow when it arrives. If it does not fail then we will know the battery was the issue. If it still fails with the new Lipo battery, then I will have to believe the ESC is the problem, or perhaps the transmitter/receiver. (Doubtful).

The new transmitter is pretty slick. Yes it does have dual rate, so I can lower the throttle down to 70% for my kid. Also, I love that I can tweak the acceleration curve of the throttle via the tx, so that it doesn’t violently pop wheelies every time I start from a dead stop. The Gyro on the receiver helps significantly when starting from a dead stop on gravel and loose dirt. Shoots off straight instead of a u turn. Amazing stuff.

 

[Guilleshop]

Note to admins: please move this to electronics sub forum. Thanks

 

[X]

Note to admins: please move this to electronics sub forum. Thanks

Got ya covered.

 

[P0SEID0N2025]

This is what I’m thinking too. I have a lipo 2S 5200 mah on order and will stress test against it tomorrow when it arrives. If it does not fail then we will know the battery was the issue. If it still fails with the new Lipo battery, then I will have to believe the ESC is the problem, or perhaps the transmitter/receiver. (Doubtful).

The new transmitter is pretty slick. Yes it does have dual rate, so I can lower the throttle down to 70% for my kid. Also, I love that I can tweak the acceleration curve of the throttle via the tx, so that it doesn’t violently pop wheelies every time I start from a dead stop. The Gyro on the receiver helps significantly when starting from a dead stop on gravel and loose dirt. Shoots off straight instead of a u turn. Amazing stuff.

Yeah my friend drove his ecx amp on the same setup but with a 5000mah nimh and it cut out constantly.

 

[Guilleshop]

This is really good info. I guess that settles it then. Nimh not really supported as the onyx manual states. Sucks cause I really don’t want lipo around my kid. Ugh

 

[Lephturn]

It could be thermal cutoff as well. Are you checking motor and ESC temps?

I would definitely go LiPo for the much longer run times as well as the better ability to handle the power draw of brushless.

 

[Guilleshop]

It could be thermal cutoff as well. Are you checking motor and ESC temps?

I would definitely go LiPo for the much longer run times as well as the better ability to handle the power draw of brushless.

I have been checking motor temps at less than 130F and esc at 105F.

Also, I do not think this is a thermal cut off problem, because the ESC light is not giving me any thermal cut off blinking codes. In fact I get no blinking codes whatsoever with the problem occurs.

 

[Lephturn]

Good, you can rule out thermal shutdown.

I am using a 5,000 mAh 50c 2S Gens Ace in mine and it works great and runs for over half an hour. I also have an HRB 2S that runs well. Get whatever you can get next day from Amazon for a good price and pick up a LiPo balance charger.

This video is a good overview and has recommendations for chargers too.https://youtu.be/1gb8Oohhciw

 

[Guilleshop]

Good, you can rule out thermal shutdown.

I am using a 5,000 mAh 50c 2S Gens Ace in mine and it works great and runs for over half an hour. I also have an HRB 2S that runs well. Get whatever you can get next day from Amazon for a good price and pick up a LiPo balance charger.

This video is a good overview and has recommendations for chargers too.https://youtu.be/1gb8Oohhciw

Thanks. Are you running the same motor and esc setup as mine? Onyx/Kinexis?

I have a 5200 mah 60c lipo from Zeee coming today directly from amazon and will be testing.

edit: I do have a lipo compatible smart charger and also I will be enabling LVC on the ESC at 3.2v.

 

[Lephturn]

No, I have not put brushless on it yet as the metal gears are back ordered.

Dont rely on LVC alone, it relies on total voltage. I run a cheap voltage checker and alarm set to 3.4v so it alarms when one cell hits that even under load. That normally means they end at 3.7x volts per cell at rest which will extend life and avoid damage. when you get a weak cell it will drop fast under load and can go below 3v even though when you stop and check it may be 3.5.

 

[Guilleshop]

Update:
Lipo 2S 5200 mah 80C arrived.
Tested for 10 mins several full throttle runs and no issues so far.
I can’t believe people run 3s in this setup. It’s already pulling wheelies like crazy and I have backed up the slipper nut. Still wheelies if I start half trigger lol.

I will keep on testing. So far it seems the issue was NIMH with this esc, sadly. I really wanted the safety of NIMH for my kid.

 

[Doctyler2020]

Update:
Lipo 2S 5200 mah 80C arrived.
Tested for 10 mins several full throttle runs and no issues so far.
I can’t believe people run 3s in this setup. It’s already pulling wheelies like crazy and I have backed up the slipper nut. Still wheelies if I start half trigger lol.

I will keep on testing. So far it seems the issue was NIMH with this esc, sadly. I really wanted the safety of NIMH for my kid.

Just teach him responsibility with lipo. My kids run fine with them. Educate them and you'll have no issues and more fun. Just keep in mine...you may want to do metal gear upgrades...if you haven't already

 

[Guilleshop]

Oh I upgraded to the ecx metal set. BUT!!! Broke teeth in the METAL gear from the differential within 30 mins. Crazy!

Second set has held off fine.

 

[Doctyler2020]

Oh I upgraded to the ecx metal set. BUT!!! Broke teeth in the METAL gear from the differential within 30 mins. Crazy!

Second set has held off fine.

that's crazy. I have done some stupid things to those metal gears..even 6s and no issues. May be you orginally had a set made on Friday ?.

 

[Guilleshop]

Well I spoke too soon. I had a run today and within minutes the vehicle started stalling again, and yes this time with the lipo battery.

I observed the transmitter RSSI and I can see it going to NULL every time it stalls! My receiver connection seems solid at the esc etc and the antena is zip tied to the rear frame, but away from motor or any electronics as per picture.I’m losing my mind here. Any ideas? I may have to exchange he the radiolink Transmitter unit and see if that’s the problem ?

 

[Doctyler2020]

Well I spoke too soon. I had a run today and within minutes the vehicle started stalling again, and yes this time with the lipo battery.

I observed the transmitter RSSI and I can see it going to NULL every time it stalls! My receiver connection seems solid at the esc etc and the antena is zip tied to the rear frame, but away from motor or any electronics as per picture.I’m losing my mind here. Any ideas? I may have to exchange he the radiolink Transmitter unit and see if that’s the problem ?

Disable the gyro. Try to run it without the gyro on. Its built into the reciever. Sorry dont know how to disable your version. I have older version of that radio without gyro. And the gyro style recievers always give me fits. Radio links can use both versions interchangeable.

 

[Guilleshop]

I know how to disable gyro. I honestly don’t think that’s the problem though. Gyro messes with servo adjustments. I’m losing throttle most of the time while maintaining the servo steering. Other times I lose both.

Disable the gyro. Try to run it without the gyro on. Its built into the reciever. Sorry dont know how to disable your version. I have older version of that radio without gyro. And the gyro style recievers always give me fits. Radio links can use both versions interchangeable.

 

[Doctyler2020]

I know how to disable gyro. I honestly don’t think that’s the problem though. Gyro messes with servo adjustments. I’m losing throttle most of the time while maintaining the servo steering. Other times I lose both.

Yeah its problably not...but I was thinking maybe the reciever has internal issues and maybe gyro causing brown out. Have you tried to add a cap for poops and giggles? Just to rule out voltage drop?