Couple of issues wih my Mamba Max
 

#1
I've had my MM for about 2 months. I've had the following problem sinice i got it. After a little bit of running my MM will stop working all together, then after a couple of seconds start up again. I'm using a UBEC with 14 cells & a 7XL with a 13/46 gearing in my MBX5.

#2
It thermaled for the first time today after only 5-6 minutes of running at the most. My fan broke so the temp reading was 200 using a ofna temp gun. I normally was using a 5 volt fan getting power from the reciver worked fine. Then i switched too a 12v fan getting power friom te speedo the part of the fan with the blades popped off last week & i popped it back on. Bu today it stopped working altogether. The temps outside were great less the 80 degrees & the body was vented very well . Do you guys think the gearing or the fan not working is the reason for the thermal shut down ?. My gearing is a 13/46 with a 7XL on 14 cells.

That gearing doesn't sound unreasonably high. I wonder why it's getting so hot?? What do you have your MM settings at? I would lower the timing and lower the starting power to help ease up on the controller a bit. What is the temp on the motor and batts?

I think the fan breaking was a factor. As for motor i forgot to check.


What do you think about the speedo cutting off after a little bit of running. I think it has to do with the UBEC because i had no steering when it cut off. Then maybe 3-4 seconds max it would start back up & run for a while.

Well, if your BEC is cutting out for whatever reason, it will affect steering and throttle. The ESC gets the throttle signal from the receiver and if the receiver loses power, then there goes the signal. Who knows, the BEC could have a bad solder joint, not rated for the current the servo and fan needs, etc. You can always try a receiver pack to verify that it's the BEC.

I plan on trying a reciver pack on my next outing When i had my BL mbx4 i used a reciver pack with no issues. I'm hoping the UBEC is the reaon for it cutting out.

Also i just reprogramed my speedo. I lowerd the timing from normal to LOW & start power to low.

What BEC are you using? Sometimes a properly sized capacitor can help a lot to even out the bec voltage, smooth out current pulses, and filters any noise from the bec output...

Im using a UBEC that i bought from mike.

It's kinda rare, but I've heard a couple people have a problem with them. Could be a loose solder joint or something equally simple.

It sounds like a ubec prob.

I hope thats the problem leroy . Brian thank's for your repliys.

yeah hopfully the bec a lot easer do deal with.

Yeah, I hope it's the BEC too. Good luck, and let us know what it turned out to be.

Hippie; You did removed the red wire from the ESC, right?
Seems to me like the UBEC is loosing signal.. Either that, or the receiver is not working properly. That thermalling you had last time is result of the fan going off-line, but IMO it should run longer without a fan. It can be the timing indeed. Sometimes a softer timing makes the motor hotter than it was.. (noticed this with my schulze/plettenberg setup) if i recall this correct; a 2 pole (hacker) needed a harder timing than the 4 pole plettenberg.

I would think if its the UBEC, the truck will be freaking out and cogging badly as well. That usually goes hand in hand. The fan breaking will do it also, its holding the dead air on the controller. No fan is much better than a poor fan or broken fan.

It's not that a fan isolates a heatsink. it's not helping the airflow, i agree.

A ubec can just drop out, it's not said it's stuttering, it's just stopping. A ubec with a thermal problem or such, might just loose it's power. Not necessarily causing a stuttering/cogging problem.

It's quite simple; if it's not the UBEC, it must be an error in the receiver. Steering doesn't work, truck won't move.. First thing I suspect is the UBEC. If you have got an external pack, test it.. If it still does the same; replace the receiver.

I went to the track today with the UBEC removed & a reciver pack installed. It still lost the signal after about 5-6 minutes of running.

if it shuts down it will cause a shuttering problem, indicating it has shut down.

Got the red wire unplugged going to the Rx??

Did you loose steering to when it happened with the rx pack?
If so I say rx is faulting.

No stuttering just looses signale for a couple of seconds then kicks back in. Temps were around 140 on the side of the MM heat sink , & i still had steering. Yes i have the red wire unplugged.

Ok. Have you tried to change the gearing a little?
I may be thermalling and the fan is cooling it off before you get a accuall reading of temp.

Leroy i've thought that maybe the issue but i dont have anymore gears . Can i call you ?.

You got pm.

I dont think its esc related.

I think there may be something wrong with the esc... I have one that does something similar. It's going back to CC but I haven't sent it yet.

Mine will start doing it after a few minutes... and once it does, it happens over and over. It "reboots"... shuts off and back on. It does a beeping/flashing thing like when it's first turned on... I'm not sure if it's exactly like the same or not. I guess I should have paid closer attention.

I played with it the other day and it will even reboot with just a slight throttle input if there's a high load on the motor, like a foot in front of the car. :)

It can't be a failsafe kicking in... like low voltage, over current, thermal... all vital signs are good. Well, it could be a failsafe, but it's malfunctioning.

It's not supposed to do this and it's never done it before.

Edit: Oh, and I have tried 3 ubecs, 2 batteries, 2 rx's, 2 servos... no luck. Only thing not changed out was the motor and esc.

incorrect; if the UBEC would shutdown, you would not neccesarely have a stutter, as simple as that.

Weird thing now the UBEC is replaced with an external pack, that you keep the steering. while the esc shuts down;

Mike, here are a few q's;

-Did you tried another set of batteries? and what batteries is it that you are using?
-Is your LVC disabled?
-have you got another receiver to try?
-did you tried reprogramming the esc?

I talked to hippie on phone. The buggy he used to run was geared lower than
the buggy with problem. Higher gearing more amp draw more heat. Yes the
fan helps cool the esc but it is still cooling while you are trying to get temp gun
and a temp reading. He can't drop the gearing for way the buggy is set up.
Well he can but it is not easy or cheap. How else could one tell if it is a
thermal problem if you can't change gearing?

Maybe use some smaller tires somehow?? I would also decrease the start power as much as possible. That should also be a little more gentle on the ESC...

Rene in answer to your ?

Yes 3800's
Yes
Yes i will try a different reciver latter.
No

mabey try reprogramming the esc because that is the only thing on the list you did not try.

@ rchippie; 3800's of what brand?
Please let me know what the other receiver does.

wrong. Its highly likely that it would stutter. :028:

My MBX 4 had a 7XL with a 12/51 or (4.25 ) gear ratio & 9920 no problems. My MBX 5 has a 7XL with a 13/46 or a (3.6 ) gear ratio & MM. Both on 14 cells could that be the issue.

No, it would run hotter for sure, but not going to stutter because of that gearing assuming your last one ran good. Change 1 part at a time on the electronics, you will find it. Make sure the servo and esc wires arent pinched or insulation bad, that will do it also.

Its either

ESC
Tx
Rx
Rx batt
UBEC
servo
Battery

swap em one by one.

Brian if the controller ran to hot would'nt thermael ?.

Not always. Never count on a thermal for anything, they will often smoke before they thermal. I have had one get extremely hot and not thermal, then never build power again and glitch and shutter. It still worked, but the upper RPM range wouldnt work. I would check all the simple stuff before you jump to conclusions though.

Hippie, Yes, a controller would normally thermal, if it runs too hot due to overgearing or such

If a weird short-cut is occured (or an error in the controller itself), it can actualy burn down. But if it gets hot because of a 'normal' situation, such as overgearing, the controller would shutdown, there is a PTC or an NTC in it which measures the temperature, and tells it when to shut down to prevent a meltdown.

Trust me Hippie, ask Jeremy as well, he can back this one up....

In a perfect world they all thermal and bunnies run free.

Not sure if Serum is disagreeing just to disagree or what, I would like to see some facts to back up this information. Then I can send you several bags of "facts" also. I have seen it numerous times in person, controller smokes...regear, try same new controller, runs for a year.


Now for my facts....
Here is a Hacker ESC in perfect working order, overgeared and nothing else.
I guess this is a "thermal"
http://www.bomb-proofproducts.com/im...r/DSCF0094.JPG

Not trying to fight with you serum, but you are giving incorrect advice that can be a costly mistake for someone who takes it as fact.

You are both right, and both wrong.. lol.

For example, the boys at CC swear the MM will protect itself, and they have tortured them with gearing, etc and it will not just self-destruct.

But we know from experience that a controller can self-destruct before it's self-preservation devices can kick in.

Maybe the MM has superior current/thermal overload protection than other escs... but I have seen a controller shut down like it's designed to do, and then one day it just smokes instead.

There is no absolute one way or the other.

I havent smoked the MM, and glassdoctor, I would be extatic of you are correct and hope you are. But, I have seem some of the best of them go up in smoke....And this includes Castle's controllers that were also suposed to be unsmokable, and only issue was gearing...and it was off by 2-3 teeth on the pinion. So, CC's almighty baracuda didnt thermal (mechanical brakes used, esc set to no brakes), and it was suposed to the the most robust esc in its class. It smoked violently after 2 minutes. Not a single thermal.


Exactly glassdoctor, thats why I said never count on a thermal to save it.

Disagree; in fact that picture of an ancient speedo isn't realy helping, do you think? and a hacker or a schulze isn't an MM either.. Hackers where not known to be the most stable ones available.

If you simple read a bit better, you would observed there are more words in my sentences i use.

if you read it, you would have seen the word 'normally' i typed in that sentence..

But i personally think you bring along a rather large amount of attitude in your posts.

Just read my earlier post a bit closer than you did, and you will see there is NOTHING in it that isn't right. (perhaps some grammar errors, but that is not the point right now)