1/8 buggy mamba max esc overheat ? - RC-Monster Forums

Jason · 01:52 PM

I just got my 1/8 buggy today ( CEN MATRIX ) and the esc overheat badly .. I tried two different mamba max esc and two different motor still the same both motor is ok but esc can goes up to 200f in maybe 2min ... the bec was disabled ... punch control 50% ... motor timing lowest .. start power low ...

NEU 1509 2700KV MOTOR :

Differential Ratio: 2.888888888888889
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 13
Total Voltage: 14.8
Motor KV: 2700
Tire Diameter (inches): 4.3
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0082
Spur/Pinion Ratio: 3.54 : 1
Total Ratio: 10.22222 : 1
Tire Circumference (inches): 13.51 inches (343.12 mm)
Total Motor Speed: 39960 RPM
Vehicle Speed: 50.01 mph (80.33 km/h)
Effective KV Value: 2700
KT constant: 0.5 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

FEIGAO 8XL MOTOR :

Differential Ratio: 2.888888888888889
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 13
Total Voltage: 14.8
Motor KV: 2084
Tire Diameter (inches): 4.3
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0073
Spur/Pinion Ratio: 3.54 : 1
Total Ratio: 10.22222 : 1
Tire Circumference (inches): 13.51 inches (343.12 mm)
Total Motor Speed: 30843.2 RPM
Vehicle Speed: 38.6 mph (62 km/h)
Effective KV Value: 2084
KT constant: 0.65 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

BrianG · 07.31.2009, 02:41 PM

Speeds over 30-35mph will tend to overheat a MM. Don't forget it's technically a 10th scale ESC meant for lighter vehicles. Gear down is the answer. Unfortunately, the fairly low reduction in the diff makes this difficult. You are already at 13T. 12T gets you in the 35mph ballpark with the 8XL, but still may be too hot.

I normally would not advise this, but try a fan on the ESC.

littlegiant · 07.31.2009, 02:42 PM

Is the Neu a 4 pole motor? If it is, use 15 timing.

It doesn't sound right that your mmm will overheat with your setup.

How heavy is your setup?

BrianG · 07.31.2009, 02:43 PM

The post says a MM, not a MMM.

Jason · 07.31.2009, 02:47 PM

I dont have any fan and no 12t pinion in hands.. do you think it maybe the center diff fluid ?

I running e-revo and heavier truggy on mamba max and no problems at all dont know why got in trouble with this lighter buggy...

littlegiant · 07.31.2009, 03:13 PM

Quote:

Originally Posted by littlegiant

Is the Neu a 4 pole motor? If it is, use 15 timing.

It doesn't sound right that your mmm will overheat with your setup.

How heavy is your setup?

Ok my mistake. I tot you were talking about a MMM.

Jason · 07.31.2009, 03:49 PM

the stock diff ratio is 2.8 how about if I put my kyosho diff the new ratio is going to be 4.3 .. ?

Differential Ratio: 4.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 50
Pinion Tooth Count: 13
Total Voltage: 14.8
Motor KV: 2700
Tire Diameter (inches): 4.3
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0082
Spur/Pinion Ratio: 3.85 : 1
Total Ratio: 16.53846 : 1
Tire Circumference (inches): 13.51 inches (343.12 mm)
Total Motor Speed: 39960 RPM
Vehicle Speed: 30.91 mph (49.65 km/h)
Effective KV Value: 2700
KT constant: 0.5 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

Bondonutz · 07.31.2009, 04:21 PM

Quote:

Originally Posted by BrianG

I normally would not advise this, but try a fan on the ESC.

OMG, can't beleive I just read that.

07.31.2009, 04:56 PM

Maybe someone hijacked BrianG's account and is posting crazy things Brian would never say.

ZippyBasher · 07.31.2009, 05:31 PM

Would adding a CAP work to lower temps?

I just setup my Losi 8b with a MM and CC/NEU.

Doesnt get as hot as Jason's, but about 155-160 after 15 minutes. Dont like running Electrics this hot and was thinking of adding a CAP. Then a fan if still too hot...

Would that help?

Snipin_Willy · 07.31.2009, 05:45 PM

A fan till help the most, but keep in mind they do go bad from the dirt and dust. And 5v DC fans aren't exactly cheap either. If it were me I'd use a fan. I run a small 25mm fan on my MM running 4s in a crt.5 (Neu 1509 motor). I had to use one even with an external BEC. A MM esc just seems to struggle with heat on 4s without major mods.

suicideneil · 07.31.2009, 09:47 PM

An external cap would help a bit, needs to be 25-35v, low esr, 105*C, 2000-4000uf.

A small fan would also help; both these mods are 'bread and butter' things you do to the MM to make it work in a 1/8 setup, I wouldnt use it otherwise and just buy a proper 1/8 esc to start with instead..

As for swapping the diffs to lower the ratio, that would actually work rather well, but then you still cant gear to high otherwise temps climb, so the mods mentioned above need to implemented. Mike sells caps, as do Tekin, or hit up DigiKey.

jsr · 07.31.2009, 10:25 PM

As previously mentioned, a MM will heat very quickly on 4s. Even on 3s, on a 1/8 vehicle it will likely heat up. A fan makes a big difference, but when I had my MM, I found it to heat very quickly even with a large fan blowing above it. 50mph is definitely too tall a gearing and the Feigao may be too inefficient to run the MM on a 1/8 vehicle. Definitely use shorter gearing, but then you give up a lot of speed to keep the MM cool.

glassdoctor · 02:38 AM

What tires are you running? If you have typical 1/8 tires, they are 4.5" and with a little ballooning, you are geared for around 60mph with the 1509... way high unless you are trying to just do some speed passes. Get the 3.3 diffs in it, and drop the pinion a couple teeth. That puts you more like 40mph on the calc which is still fast for a MM/1509 but it's a lot better than 50-60mph

florianz · 08.01.2009, 06:36 AM

you should add an external bec/ubec, and disable the mm's bec by removing/unplugging the red cable. of course you need some good caps and a fan as well. but that's done quickly. I'm pretty sure the main problem is the build in bec, which is simply not made for 4s and therefore it gets very hot. together with a proper gearing that should be working well. for example, an ezrun 150a has a "switching bec", they don't get that hot on 6s.

I always add some extra caps on my esc's, it gives you some extra protection. they compensate peaks in high voltage.

I never had a problem with dirt on my fans, as almost no dirt gets inside the buggy. you plug the fan into the receiver or connect it directly with the ubec. or get a 12v fan and connect it w/ the battery cables.