Mamba max getting HOT fast!
 

i dont have a temp gun but i can only hold my finger on the heat sink for 3 secs after only running for 2-3 minutes, I installed the CC UBEC last night and it didnt help the problem, still very hot, its 45 degrees outside and the motor (Feiago 9l) and mambamax temps are WAY up there, my battery (3s 5000 maxamps) is not even warm at all, its almost as cold is the temp out side. Are these kind of temps normal? im gonna get a temp gun asap but what can i do to get it to run cooler? im taking the plugs to the motor off and direct soldering them, maybe this will help and little bit with the low speed cogging but what about temps?

Could be the gearing... it's in the LS10? That should be ok...

Just an idea to throw out there, is it possible that the screws holding the motor to the truck are penetrating the motor windings? That would explain the heat, and the cogging.

You did disable the BEC on the MM, correct?
What is your gearing?
What surface are you running on?
Any fans on the MM?
Do you brake a lot?
What are your MM settings?

Just a question, how hungry are the 9l's? That could be an issue for the MM too?

DANG i bet thats what it is! i thought i needed to trim those some because i knew theyd be close but they could be touching.

-i did disable the mm bec
-gearing is 13/54 its only geared for like 33-35 mph (low compared to everyone else)
-smooth concrete parking lot for testing
-no fans, a rcmonster heatsink on the motor thats all
- the mamba max is setup right according to the book (high start power and all for the 4wd and heavy truck)
-truck is just barely under 5 pounds

ill check and cut my motor screws off 1st and then see how it goes from there.

I did the same thing with a feigao, screws were too long and it did heat up very fast, plus my battery almost puffed! I tried shorter screws, but the damage was done and I had to replace the motor. I did it to a 7xl, but I am sure all of the motors would react the same. Hope that you did not kill the 9l, it is a great motor for that application!

It shouldn't be a problem if they are just touching. The windings have a coating on them (epoxy, I think), on top of the normal insulation they have. So to get to the bare wire you'd have to push past the epoxy and thin wire insulation. But it's very possible that when the screws were tightened down the wires were punctured.

so if the screws left marks in there my motor is ruined?

just test the motor to see if it still works.

if it does then awsome. if it doesnt.... then you need to buy a new one.

It depends. If the windings have been damaged from being shorted out by the screws (assuming the screws are cutting into the windings), then the motor is done. If the screws didn't cause much current to flow through the short, then it's fine. Like t-maxxracer32 said, try out the motor (with shorter screws, of course).

Well my screws had left markings on both sides of the windings, i did cut them and tried it anyways, it didnt cog as much (still a little), it ran like a bat out of hell, but sadly you could have cooked breakfast on this thing after only a minute. the mamba was hot but i could hold my finger on it for 4-5 secs the motor burned my finger after 2 secs (I now have a burn on my index finger, sucks). i guess the motor is a goner? i didnt even bother trying direct soldering the plugs yet, i dont really want to chance puffing my brandnew battery or my Mamba max by continuing to run it if the motor is bad.....

Sounds like the magnet is gone on yours. Does it still have some resistance when spun by hand? If the feigaos get too hot the magnets usually demagnetize, due to their cheapness! Maybe the too long screws caused the high resistance - heat and that caused the motor to cook? Who knows, do you have another motor you can try with the combo to rule out other problems?

nope that the only motor i have/had, it smells now, kinda a burnt oil smell, mamba max cooled down really really fast after i unplugged it, it took a while for the motor.

i have the motor apart now and its definetly the rotor/magnet that smells burnt, the windings in the can right there surrounding the rotor all look burnt too. Ill try and get some pictures up. It still had a little magnet left in it, not much resistance, i spun the motor with the pinion on with my finger and it rotated 4-5 times after i let go before it stopped, when i got it from you james it would stop after 2-3 rotations after i let go.


Mike is out of stock of 9L motors could i use a XL motor of the same kv as the 9L? id like to get another motor pretty quick, if not where could i find a 9L for a decent price with FAST shipping?

Sounds like it is toast. If mike can't cant get you a 9l try steven at www.offshoreelectrics.com. Usually he has the motors in stock and he gets me stuff as fast as mike does. He has great customer service, and a great rep in the rc boating scene. Lots of cool stuff on his site too, mostly boat related. I like brushless boats too, so I usually use him for hulls and equipment.

My dad just took a look at it, (he is an electrician) and he said the magnet may be weaker but that wouldnt have been running like it was outside, he said the windings are shot and it was junk. So i need a new motor......... the next one will be direct soldered and will use extra short scews lol

The direct soldering does help, I have had alot of problem with 4mm plugs myself. Never had a motor react the way yours did, but have had some 380 feigaos just fail out of the blue. I have also had the shafts come loose from the magnets to. The feigaos are good value, but their quality control leaves something to be desired...

they dont have 9L or 10Ls instock ethier. they have a 6xl that about the same KV is that too much motor? what would be the positives and negatives to running an xl? would my runtime be shorter? they have much more torque dont they so would i have cogging issues still? im new to all this shed a little more advice. i need a motor. i wanted to go to this race next weekend but i have to get this thing sorted out first and get some driving time behind it.

I would stick with the l can motors. You could run a 7xl on 3s and gear it up. The increased torque of the xl may make up for the lower kv and higher gearing. Not too sure in that situation, as I have not tried an xl in a smaller vehicle yet. You could try one of the ammo motors that tower has on sale, great price and the 36/56/2600 or the 36/50/3300 may work for your application. Can't go wrong with the price, buy both and give them a try!

http://www3.towerhobbies.com/cgi-bin...MO&S2=&S3=&S4=

I thought in another thread you said you tryed the ammo motors and they werent up to spec, and that you had to gear down alot or they got really hot......i dont want to down grade from a feiago, plus i dont know if the mount pattern is the same. Im gonna call mike and offshore electrics and see when is the soonest they will be getting some 9Ls instock.

im looking at the chart here and
9L= 2731 KV this puts me right at 33,000-35,000 rpms
all the ones near that are
6XL = 2779
7XL = 2382
10L = 2458
12s = 2958
13s = 2730


the XLs and S cans are the only ones instock so if they are not getting any L cans motors soon what would be my best bet, i assume the S cans would run much hotter than an L or XL because itd have to work harder in truck, so is an xl motor of the same KV like the 6XL over kill for a 5 pound truck?

Has anyone else tried an XL in a lightweight, how did it do?

When I tried the ammo motor, my gearing was too tall. I had the emaxx setup for an align 600xl 1650kv and used the same gearing for the 1800 ammo motor. Plus the emaxx is way heavier than the ls10 so it put a higher strain on the motor. I have recently heard other users with more runtime have good success with the ammo motors. I just used the wrong motor and gearing for my application. I am still learning, seems like the lower cost motors are more sensitive to gearing than the high end stuff.

so what do ya think try the ammo 2600 or the 6xl?

Basically, you need lots of power to launch something that big and heavy. Power is generated by voltage and current. Usually, to get high power, it's better all the way around to use higher voltage. Unfortunately, the MM is limited to around 4s. At that "low" voltage, you will need quite a bit of current to launch it with also the top speed you want.

Reducing the gearing would be your best choice. No matter if you get a fast motor and gear down, or get a slower motor and gear up, the same amount of work is being done and the ESC/batteries will be working just as hard. The only advantage in a slower spinning motor at this point would be a slightly better efficiency IMO.

so which motor brian?

if i keep with the 13tooth and get a 7xl id have better efficiency and be geared for 35 ish and under. that long motor would have plenty of grunt on my 5000 3s to get rid of cogging and have plenty of start power right?

I thought my truck was kinda light compared to most 4x4s like maxxes and the 1/8ths.

would this motor work good they have two in stock and it has a heat sink built in. (looks like james already bought one and wrote a review too, lol)

https://www.unitedhobbies.com/UNITED...idProduct=2030

that is the same 9L as i had right just a different can?

I guess i got lucky, I used different screws than provided by Neu and accidentally got into the windings. its fine though

heck i just realized thats from that company in hongkong that take a month or two to get it shipped here.

Im having a very similar problem . When i first hooked up my MM with a 3/4 charged pack & the kit tires it worked fine. Then i fully charged the pack & put 2.2 truck tires on there & now when i pull the trigger the car takes off & then it seems like the MM applys the brakes or cuts in & out . Then i let of the trigger for a second &the pull the trigger again. It will accelerate then it does the same thing over & over again. im using a 7s with 12/46 gear & 2s lipo with the lvc set at 6.4. any ideas ?.

Mike came through and saved the day he had one 9L motor left and i ordered it today along with some battery straps so i can ditch the zip-ties.