9XL & Mamba Max Shut down!
 

Hey I've been trying to tune my combo recently and been having these problems:
- ESC shuts down after 2 min. of runtime then it would re start
- drilled my pinion to fit the 5mm shaft of the 9xl and lost 2 grub screws already.(I shaved of some meat on the 9XL shaft so grub screw has something to bite on)
by the way my gearing is a 77t spur and 18t pinion
any ideas on how to correct these issues? by the way im still using the stock settings for the MM. Also for your info i'm only using 2x 3300mah ni-mh 7.2V. Would appreciate some help thanks. And if there's any old threads about this pls. tell me which one thanks

Does it get hot? No lose connections?

Locktight in grub screws?

it gets hot but not so cause i could still touch the motor and esc. i dont think its a loose connection cause i wouldnt need to touch anything for it turn on again

tried to locktight the grub screw yesterday and still lost one today

Check for any "error code" flashes on the esc when it happens....

Let the locktite dry over night before running your truck.

Try to drop 3-4 teeth on the pinion to see if that solves your problem.

Sounds like a thermal to me... Can you measure the temps? Or as DR said, any beeping or error codes?

What's the gearing?


Do you have a fan on it, a fan is a must. BEC is disabled as well?

I highly doubt with his 18:77 gearing that it's misgeared enough to cause a thermal problem in that short of a time period. I would be more inclined to believe it's thermalling due to the pinion slipping on the motor shaft when the grub screw falls out.

Opps missed it... Yeah you're right. Its actually geared lower than my 8xl. The prob must be somewhere else. 2 min awfully fast...

What typr of driving are you doing? Grass, street etc?

been driving on grass. im kinda simulating my runs on a race track cause our nationals is cming up and im trying to tune my truck. by the way how would i knw what the erroe sounds like on the esc?

I think 18/77 wouls be too low geared and it would run very slow and might be over-reving. How did you get a 77 tooth spur gear? and what tires are you running?

Can you give us all your setup for the motor and esc?(include the tires as well)

I have run mine with 40 series wabash and bowties, with 17/66 gearing and 12 cells with no trouble for over 15 minutes, with 4.4k's from Maxamps and the only problem i have had was going to a reciever pack because the internal BEC couldn't keep up (expected), but i haven't had trouble with heat or cogging like some others have described.

Seems to me that you are not using an external UBEC/receiver pack.

I had that problem with 8 cells on the MM, i am using a very enthusiastic servo which takes quite some power.

Good thought Serum. Carlog80, you can see if this is the case by turning the ESC on and just turning the wheels back and forth and see how much the ESC heats up. Since the BL motor isn't running, the only heat generated will be from the BEC...

Or just put a battery pack on the reciever and remove the middle wire from the plug.
running 12 cells on mine it would cut, but it would come back on almost imediately, I didn't push it so i don't know if it would stay shutdown for a time if the heatsink got too hot

And if you'd rather not cut wires on your rx or esc you can get an short extesnion and do ths
http://members.cox.net/tg_19/elst6.JPG

If he can touch the esc and hold fingeron that and motor. It can't be but so
hot. I would go with internal bec as well. I had a simaliar problem with a bk.
Unless he has a bending issue. Then that causes problems.

Quick Question - i will be running quark125B and two orion lipos will i need a separate small batt. pack for the reciever and or servo like those triangle or octogon packs like by venom. Or will the lipos be enough to power the motor, esc, reciever, and 333 oz torque servo. And if i do need to use one of these were do i plug it into the seervo or do i use a y conector or something thanks.

You can run a 4 or 5 cell receiver pack for the servo(s) and receiver, but it just adds to the weight and it's just one more thing to charge. Far better is to use a UBEC to bring the main battery pack voltage down to 5 or 6 volts. This lets you use just one set of batteries - your main ones. The power needed to power the receiver and servo(s) is minimal compared to the brushless motor requirements so any difference in runtime will be neglible.

You CANNOT simply use a Y adaptor to directly power the receiver as the voltage would be too high. Even 2s would be too much. You do need a receiver battery pack or a UBEC (but as I said, the UBEC is a better choice IMO).

The ESC has a BEC built-in, but if you are running anything over 3s, you should definitely use an external one. The built-in one is a linear regulator and will heat up.

I think that the drilled pinion might be causing some of your problems. The gears are cut on precision machines so that the hole is PERFECTLY concentric (in the middle). If you think about how fast 50,000 RPM is you can see that the slightest imperfection can cause big problems. Thats how vibrators work. Its just a weight with the whole drilled offcenter. Just for the record im talking about vibrators in cell phones!:005:

No, if this was the case it would had caused binding, which would have lead into overheating. like he says; it's not that hot.

well its a week till our nationals here and ill be joining the ep mt. I wrong about my gearing it a 66tspur/18tpinion. my tires are 40 series bowties on wabash with 23mm hex. Have a question how do u turn of the bec on a MM? will try to tune my truck this week for the big race. ill update u guys during the week if it works out already

To disable the BEC, just remove the red wire from the throttle plug. Either that or use a small servo extension with the red wire totally removed.

so by disabling the bec u think it will solve the problem of my esc shutting down ?

Yes, possitive. You need an external batteriepack/ubec however.

hey thanks guys! u guys are always a big help! thank you! will update you guys as soon as i get things working.

the external battery pack will be connected to the reciever?

Yes, in the battery slot. Be sure to get the middle wire out of the esc plug

so all in all i would be just fine running 2 lipos and i would not need any other source of power than the two lipos to run my reiever and settering servo right.

ok ive locktight my grub screw already and im leaving it over night to dry up. Now by tom. ill be getting a ubec from our local hobby shop. does the ubec brand matter? i've put a fan on top of the mm just to cool it down but my problem is that when i connected the plug to my reciever's batt it didnt want to work? i've tried connecting it staight to the battery and it works. do u think its my reciever that's the problem throttle and steering seems to be ok. Also, ive requested from brianG a diagram on how to connect the ubec in the system. Is there another way on getting the fan going? Thanks for the support! hopefully my mt will be up and running with no problems for the nationals this weekend. Thanks again!!!

You can hardwire the fans... to the esc's main power leads from the battery if the fans are 12v, or to the output leads from the ubec that go to the rx if the fans are 5v.

The ubec is easy to wire up... it will have two input wires that go to the battery and two output wires that go to power the rx. You will have to hardwire or make a connector to hook up the input leads. And you might even have to put a rx connector plug on it to plug into the rx...

...this is so weird...This happened to me last night with the Hellfire!! I came on to try and figure it out and here it all is already laid out!! Thanks forum...Once again you have saved the day!! now to fit all these bits into my machine...

QUESTION: if i DONT have a UBEC and i remove the red wire what happens?

If you don't have a UBEC or a receiver pack, and you remove the red wire, your receiver will not get any power and it simply won't work.

Correct. 2s is only 7.4v nominal, so the internal BEC can convert that to 6v fine without too much heating.

10-4 BG!! Mental note to self: DONT cut the read wire :026:

ok got my ubec today but shop was to busy to wire it in for me. the ubec i got is a 6v & 5v which should i use? 5v? anyway the guy told me at the shop that i have to solder it on the black and red of wires of the esc cause my setup is a series for two pack setup. (do guys get me?) and the output should be connected to the rx right?

that sounds right. 6v will give you more speed and torque for your servo.

So i pretty much have to get the external ubec if i want to be acble to drive and work my motor esc and recever and servos. also if i dont the quark speed control will be shot. thanks

If you use low battery voltage, like 6-10v, the internal BEC is fine. Any battery voltage over that and the ESC will heat up faster just because of the BEC. Whether it will fry the ESC or not is hard to say. Most should have thermal cutoffs to prevent self-destruction, but there have been instances of the internal BEC frying.

In short, I'd use an external BEC for anything over 6 cells/ 2s lipo for best results.

but i am using 2 orion 4800 wich is 4s so i pretty much have to use an external ubec right.

ok guys 1 more day to go till the nationals!!! I finally was able to install ubec and man my esc doesnt even heat up anymore plus have a fan over it! My only problem is that pinion and and grub screw loosens up after one run. i already put some locktight and still lost a pinion and grub screw. Also another problem is the hv maxx that im up against has the same top speed as i do his setup is 72/15 and im 66/18 foor gearing but i only have 12 cell nimh 3300mah 14.4 and he has 2s 4000mah 14.8. so what u guys think should i leave as is for the race this weekend?