Car Cutting Out
 

After some help really, ran my mo9e for the first time today, loved the car but had a specific issue. Every now and again, as I came out of corners the motor would just cut out. It would then come back to life around 10-15secs later or if the car was picked up...it only happened every now and again, in fact it happened early during runs and not later on...am flummoxed though! My electrics are:

Mamba Monster ESC
Thunder power 1900kv motor
I am not running a capacitor

The drivetrain doesn't lock up (it is right but when the motor goes it rolls a to a stop), and the steering carries on working. I am running it at the Clash next week so don mt have masses of time to find a solution!

Has anyone had a similar problem?
Is it likely esc, or motor?
Is it an extreme version of cogging? Should I try a sensored esc with the thunderpower?

Help!!??

sounds like your esc/reciever is cutting out and sounds very similar to the spektrum brownout issue, id first try a cap on a spare slot on the RX and that could clear your issues

It could well be a heat issue Dave, if you running the brakes on max and using motor braking, it will ramp temps up really high.

Its unlikely as Dave states he doesnt loose steering. When i had similar problems on a 10th car last year i lost the steering as well as power so a power cap solved that, but if the steering is still working its obviously not dropping out or failsafing.

What C rating is your lipos Dave?

And are you running V1, V2 or V3 mamba ESC?

Ah yes I over looked that bit :blush: id be likely to look at DCM comment then with some overheating issues

Where's your voltage cutoff set ? Sounds like a thermal issue for sure, but could be the voltage cutoff kicking in as you hit the throttle and ask the batteries to supply current. They'll drop voltage under load and it may be that they drop under the cutoff point.

Raided guys should have clarified, I don mt think it can be voltage or thermal, because it happened within 30 seconds of starting an 8 minute race on Sunday...did 3 times in the first 3 minutes, but then ran the last 5 minutes absolutely fine! So I don't think it's heat related...it could be voltage but I'd have thought that would keep doing it as well...I don't think it's a dry joint as it doesn't do it on jumps, it seems to be if it gets sideways and the wheel speed drops very low, then I apply a lot of power (which I guess DOES suggest voltage).

I think it's a v3 esc, is it worth me disabling the lipo low voltage cutoff in case it is this cutting in? Then trying a cap too (though as mentioned I'm guessing if t was the bec it would kill the steering too)?

The only other thing I can think of is if the esc has a problem..I noticed if its turned on while at my pitting table then it sometimes beeps as if its resetting itself!?

If its V3 chances are its ok, i know the V1 and V2 had issues which were rectified in the V3.

You could try a castle link and do a firmware update and check the settings on there.

Failing that it might be the motor. For a cheap replacement you cant beat the XErun off ebay for the money.

The other thing I'm wondering is as its set on "auto lipo cutoff" whether it's mistaking my 4s for 5s when fully charged early on, so then detects "too low" voltage under load early on?

Does anyone know, of the low voltage cutoff clicks in on a castle esc, does it kill steering too or just throttle?

In terms of isolating the issue, is it muchore likely to be esc/battery related than the motor (it is a sensored motor, running sensorless on the castle as the monster doesn't do sensored)?

Just to be sure Dave, manually set the Lipos cell count just to be sure, it could be as you said over detecting voltage.

Also, if the ESC goes into lipo cut-off, you dont loose steering so you could be on the right track there.

Ok, I now know what it's doing but not what it means, does anyone know:

When I steer quickly you can see slight dimming of receiver/tp light.

However, what happens is when I turn the esc on it initially double beeps and flashes green/yellow, then a couple seconds later it does it again, then a few seconds later beeps 3 times and all green/yellow/red flash together at the same time, then it works! I just tested it on a bench and it stays working as I stop/start at low revs, but if I then wiggle the steering back and forth heavily and let the revs drop it dies...then goes through the beeps/lights procedure again! So it's like it's resetting the esc and forcing it back into startup mode...

...anyone know why!? It's either lipo cutoff or bec voltage I guess??

hmm, try a different servo, sounds like your one is a bit dodgy

I had a very similar problem with my SC on Sunday.

Hobbywing 8th speedo, with a Savox 20kg servo, Futaba receiver.

Would cut out occasionally, and then come back in.

A capacitor helped on the receiver, but not enough.

Seems the Hobbywing BEC isn't man enough for a decent servo.

I'm going to try an external UBEC.

Hmm, emergency external bec purchase! Not looking forward to wiring that!!

Think the servo is just powerful rather than faulty!

Oh crikey. Who's going to solder that in for you mate:woot:
Let us all know how it goes at the clash

I have seen on other forums that your particular ESC has had that problem with others, and it was solved by installing an external BEC - either that or by installing a higher quality ESC.

I have seen those exact symptoms happen only in 2 instances.

1. the internal BEC is faulty.
2. you have the controller throttle endpoints set at 150 instead of the stock 100. i know thats sounds weird but for what ever reason it was lipo cutting out when i did that on one of my cars. After changing everything i adjusted the throttle endpoints back down below 115 and it went away.