Mamba Monster cutting out at full throttle.....
 

I have a 12lbs converted savage that use with the following setup...

Mamba Monster
Feigao 7XL
zippy 4s 4500mah 21-35c

I have been using the Mamba monster's bec and ran fine for me, although I only got to put about 5 minutes of run time on it so far cause I broke a shock shaft, but thats another story. Anyways, when ever I grap full throttle it goes for about a 1/4 of a second and then it shuts off and I have to release the trigger to get it to go again. But if I slowly grap the throttle it powers up to full throttle fine with no hesitation or glitching.

Oh and my old setup that used the turnigy HV esc did the same thing if I geared up too high, but if I ran conservative gearing it ran smooth. I thought the turnigy ESC did this on high gearing because of over current as its only a 100 amp esc, but the mamba monster esc is supposed to be 200 amp and I cant imagine I am drawing that much current. My current gearing is 48T spur with a 16T pinion locked in second gear.

Anyone know why it is doing this or what can I do to make it stop?

Did you check the Cut Off Voltage?

hi

i guess the batteries can not deliver the short amp peaks. so that would mean get better batteries or a motor with a higher winding.
what is your gearing?

bye
rhylsadar

Yes cut off voltage is set at 12.2, I am also using low timing and 100% punch / traction control to help tame wheelies.

My gearing is 16T pinion and 48T spur locked in 2nd gear. I have two of these zippy 4s packs maybe I should try them together in parallel to double my "C" rating.

Although using one pack by itself they have a decent "C" rating 94.5 continous and 157.5 burst.

You could also feel your solder connections after a while of running. If they feel warmer than the wires, you could be getting voltage drop on the connections at high currents.

As others have said;

1: Get batteries that can handle the load without as much v drop
or
2: Get higher voltage and higher wind motor. A 10XL or 11XL on 5s or 6s should do nicely.
or
3: Simply gear down. You won't get the same top speed, but your batts will thank you.

Sounds like the voltage is dropping enough to cause a controller reset. I'm thinking these 7XL setups are drawing a lot more current than anyone is giving them credit for, even though they seem to be setup within reason.

if (MMMCutOut == true)
{
checkLVC
if (LVC == notSetCorrectly)
{
setLVCCorrectly
if (calibrateESC == false
{
claibrateESC
}
elseif (calibrateESC == true && MMMCutOut == false)
{
run that rc
}
elseif (MMMCutOut == true)
{
buyBetterBatteries
}
}
}

In english check your LVC and set it correctly. Then calibrate the ESC VIA manual instructions. If it still cuts out buy better batteries.

Hmm.....

When I ran my old turnigy esc I had this same controller cut off thing when I used my 7XL and 16T pinion. But with my KB45 8XL 1700kv with a 20T pinion it ran fine on 4s and 6s, but my KB45 is dead now due to can popping. I guess I will try lowering my gearing and or using two lipo packs in parallel to have a higher "C" raiting. Eventually I want to get a lower turn motor and run 6s lipo anyway.

hi
yeah very high gearing you have there. that thing must get pretty high amp drawing. gearing down (smaller pinion, bigger spur) would be a first and easy thing to do.
bye
rhylsadar

You outta pad the nested conditionals to make it easier to see the heirarchy. :wink:

Do you know why the cap popped? Caps usually pop from overvoltage or too much ripple current (which heats them up too high). And doesn't high ripple current mean lesser-quality batteries?

I did but the forum automatically left aligns it all. :neutral:

BTW i run 16/47 gearing on my savage with MMM and all is fine. I do have an 8xl in it with a 4s maxamps 5000mah too though.

Might want to reset all of you radio settings and reprogram the esc. Just in case.

I have a few 7xl setups and they can draw some juice. I use trakpower lipos and they can keep up, but with only 4900mah, runtimes are short, like 15min with hard bashing.

"CAN" popping, as in the KB45's skipped over its threads even though I had used JB weld on the end bell threads. It popped over the threads 4 times and the last time finally finished her off. Next time I buy a KB motor I am going to make a motor clamp for it similar to the rc-monster feigao clamp.

I did adjust my throttle trim on my radio after I progamed the esc. Maybe it just needs to rearm with my radio / settings? Maybe when I go to full throttle the esc is seeing it as nothing because the trigger is moving to far or something, I dont know. But my temps arent getting very hot with this gearing.

that is what the calibration is for! Calibrate the ESC and then you know it is not cutting out because of this.
To calibrate the esc to your radio
turn on radio
hold radio full throttle
turn on ESC
it will beep then hold full brake
it will beep again
release to neutral
will beep again and then arm

THANKS!!!

I never did this calibrating like you described. Do I have to do this every time I turn on my esc / radio?

nope only once unless you change to a different radio down the line.

No, It saves the settings. You do need to calibrate the esc to your radio, even if it does arm without doing that.

Your gearing may be too tall and the battery voltage is falling enough to hit the lvc. I just mentioned the radio settings as I had that problem before.

If I change my throttle trim settings AFTER calibrating my radio & esc do I have to re-calibrate the esc / radio again???

just make sure your trim is at center BEFORE calibrating and all will be fine. Besides throttle trim should not be changed. If you had to change it to keep the truck from moving you DEFINITELY need to calibrate it. From what you say i really think calibrating will make a huge difference. If not well it wont hurt to calibrate it.

Yes.

Why would you want to change your trim after you are calibrated? I mean, that's what the calibration is for, after all.

Just set all trims/epa to default and leave them there. You'll have a much happier setup because of it.

Thanks, just wanted to know because sometimes I mess with my brake linkage / servo.

adjusting mechanical linkage will not affect the calibration but trim will.
In your case do this
get your brake servo mechanically as close as possible then trim the throttle to be PERFECT, make sure it is right BEFORE you calibrate. Once it is all good leave the trim where ever it is at then do the calibration.

Cool beans:yes:

Lunch time update....

I did the calibration thingy, it defiantly made it run smoother although I was still getting some random cutting in at out at full throttle. This could be due to this is the zippy lipo's first cycle, I will try my older pack when I get home from work. It defiantly appears as its the lvc which is causing the motor to shut off at full throttle.

good, yeah my maxamps pack takes a few to actually kick in at full voltage. at first it only goes like 1/4 power then it just hauls off into a backflip :lol::lol: I think it is your batteries. Others say the gearing is tall but i run the same gearing and mine is perfectly fine, my truck also is very heavy (full alluminum) Oh and i do run the 8xl not the 7xl.

good, yeah my maxamps pack takes a few to actually kick in at full voltage. at first it only goes like 1/4 power then it just hauls off into a backflip :lol::lol: I think it is your batteries. Others say the gearing is tall but i run the same gearing and mine is perfectly fine, my truck also is very heavy (full alluminum) Oh and i do run the 8xl not the 7xl

Sorry for the double post my work just had a power outage and upon reboot it reposted to the forum. :lol::lol: