Kraton 8s shuts down

[MeandmyRCworld]

After I mounted a 24t pinion the car shuts down after about 5 mins, the batteries are still charged, the car cuts power down and afer a few secs it's good on full power again. What could be the cause?

 

[arrmadave]

Did you check the motor and esc temps?

 

[Chris Lane]

We would need to know the specifics of what your running. If you took a new vehicle and added a 24t pinion. You aren't a newbie, give us all, the details of your rig. Sometimes the simplest thing could cause a problem. Detail your entire setup and I'm sure some experienced people on the forum will chime in.

 

[Notorious J]

After I mounted a 24t pinion the car shuts down after about 5 mins, the batteries are still charged, the car cuts power down and afer a few secs it's good on full power again. What could be the cause?

definitely sounds like a thermal shutdown. Pay attention to the flashing lights on the esc. That will usually tell you what's going on.

 

[Surchaufeur]

24t? Mght be over heating i know with the 23t it does fine so far

 

[SrC]

24T may be too over geared for that Firma 160Amp ESC to handle. If you are running that stock ESC. If the lipos don't have a High enough C rating you may be getting LVC and not Thermal Cut out. Check the light status of the ESC and interpret that better. Get a temp gun if you don't have one. Changing pinions always requires temp checks. Its very easy to push the limits by over gearing

 

[MeandmyRCworld]

We would need to know the specifics of what your running. If you took a new vehicle and added a 24t pinion. You aren't a newbie, give us all, the details of your rig. Sometimes the simplest thing could cause a problem. Detail your entire setup and I'm sure some experienced people on the forum will chime in.

'Max size pinion on the Kraton 8s is 25, so I'm safe. motor and ESC are feeling good, it's 8 degrees Celius outside, so we can rule out overheating. It's bone stock, punch 5, brakes 100%.

 

[jondilly1974]

'Max size pinion on the Kraton 8s is 25, so I'm safe. motor and ESC are feeling good, it's 8 degrees Celius outside, so we can rule out overheating. It's bone stock, punch 5, brakes 100%.

Why are the brakes 100%???? ?

 

[MeandmyRCworld]

definitely sounds like a thermal shutdown. Pay attention to the flashing lights on the esc. That will usually tell you what's going on.

Yeah I thougt so aswell but no lights flashing, nothing is overheated.

24T may be too over geared for that Firma 160Amp ESC to handle. If you are running that stock ESC. If the lipos don't have a High enough C rating you may be getting LVC and not Thermal Cut out. Check the light status of the ESC and interpret that better. Get a temp gun if you don't have one. Changing pinions always requires temp checks. Its very easy to push the limits by over gearing

I'm running it on 2 brand new Gens Aces, 5000mag 50C each.

Did you check the motor and esc temps?

It's about 7 degrees Celcius outside here, didn't bash it I just was runniing it up and dwon the treet for 10 min. No lights flashing, ESC and motor both felt nice and cool.

24T may be too over geared for that Firma 160Amp ESC to handle. If you are running that stock ESC. If the lipos don't have a High enough C rating you may be getting LVC and not Thermal Cut out. Check the light status of the ESC and interpret that better. Get a temp gun if you don't have one. Changing pinions always requires temp checks. Its very easy to push the limits by over gearing

On the stock spur the max pinion size is 25 t. It says so in the manual.

Why are the brakes 100%???? ?

Because I like me some good brakes

 

[Camaroboy383]

I would try some different batteries, we have people getting low voltage dips on 3s rigs with that size mah and c rating batteries.. let alone a monster that big.. I would definitely try it, then call horizon for warranty if it does the same...

 

[phildogg]

I'm going to assume its cutting out because of the amp limiter in the esc.

 

[Clubin]

'Max size pinion on the Kraton 8s is 25, so I'm safe. motor and ESC are feeling good, it's 8 degrees Celius outside, so we can rule out overheating. It's bone stock, punch 5, brakes 100%.

What is stock pinion tooth count?

 

[Hammer Down]

17T stock

 

[SrC]

25T is the max size the motor mount and spur will handle and what Arrma can offer in gearing.
But, it does not guaranty that a 25T will be appropriate for the Firma 160amp sustained load limit. Hence LVC or even Thermal cut will engage. Any one else agree???
There is also a Capacitor Temp Cut Out on this ESC from what I have read. An indication of poor lipo "C" rating if it engages.

 

[Clubin]

25T is the max size the motor mount and spur will handle and what Arrma can offer in gearing.
But, it does not guaranty that a 25T will be appropriate for the Firma 160amp sustained load limit. Hence LVC or even Thermal cut will engage. Any one else agree???
There is also a Capacitor Temp Cut Out on this ESC from what I have read. An indication of poor lipo "C" rating if it engages.

What I was getting at. Put stock pinion back in and run it. See what it does.

 

[Chris Lane]

What I was getting at. Put stock pinion back in and run it. See what it does.

Exactly it's not modified enough to be much else. I've seen one video of the K8s "cutting out" and those were doing deep 60+mph runs.

 

[MeandmyRCworld]

Problem solved! I reprogrammed the esc punch 5 brakes 100% motortiming 11, pulled all the connectors loose and back in. Went out on a ride still with the 24t pinion on and blasted for a good 15 mins top speed up and down the street. The motor and esc were hot but no cut off! What and why it happend is unclear but I'm happy it does what it's supposed to do!