MAX Continuous Current on MMM?

[BL_RV0]

Anybody know? I'm wondering because I'd like to run one with a Neu 1521 1.5d with pulls a max of 110a. It will be in a fairly light truck ~10lb rtr. On 6s.

[BrianG]

Reports had it for 200A and 6s...

[BL_RV0]

WOWSERS!!

[BrianG]

Yeah, 4,440 watts or almost 6HP is nothing to scoff at.

I just hope they someday make a 12s version rated at about 150A - better yet, just slap car software on their HV-110 and call it the MMM-HV. 7,104w = 9.5HP.

[BL_RV0]

When I calculate it, it says only 2442 watts. I need more power than that. Suggestions?

[legobrains]

So from the rumored specs, it seems it will be closes performing to the 22418 MGM controller:
http://www.rc-monster.com/proddetail...22418CP&cat=21

It supports up to 6 cells lipo, and 224 amps continuous, and 260A burst.

Is this right?

[BL_RV0]

What if i ran a 1527 1.5d? What's the max current on that? I can't find it.

[BrianG]

You need more than 2442 watts??? Are you gearing really tall for high speed runs or just like replacing drivetrain parts?

[BL_RV0]

Both. I SHOULD not be breaking too much... Muggy/LST diffs, center diff with steel spur, custom made 8mm CVD's.... I think you get the idea. I will be gearing high occasionally but fur the most part, it'll be set for about 45 mph.

[BrianG]

legobrains: Knowing how Castle underrates their ESCs, I would expect at least 50% headroom for bursts. So, that 200A continuous would be something like 300A bursts. Just speculation here. But TBH, currents that high are inefficient and if very high power is needed, would be better off going with a high voltage and lower current setup.

BL_RV0: max current rating is a fuzzy thing to calculate. Not many setups will pull the max current all the time. Cars are peaky, so there are going to be high current bursts that level out for most of the run. But anyway, you can guesstimate the max current. Let's say a motor is rated for kv=2000, power=3000w, and max rpm of 60k. To get 60k rpm, you need 30v. To get 3000w at 30v, you need 100A. But then, you could go lower on the voltage and up on gearing to pull more current to get that same 3000w. rpms would be lower though as well. See how it gets kinda fuzzy? And then, the max power rating is usually for a relatively short duration. 3000w is a LOT of power for a small motor!

[BrianG]

Originally Posted by BL_RV0

Both. I SHOULD not be breaking too much... Muggy/LST diffs, center diff with steel spur, custom made 8mm CVD's.... I think you get the idea. I will be gearing high occasionally but fur the most part, it'll be set for about 45 mph.

IMO, normally a 1515 should be fine for that setup, a 1521 would be overkill, and 1527 just plain silly. But since you want faster speeds over 45mph, the 1521 as a baseline would be fine.

[jzemaxx]

In an emaxx a 1521 1.5D will push you over 70+ mph on 8S. ;)

[BL_RV0]

Is there a way that I can get more current= more power without exceeding the ratings of the MMM?

[BL_RV0]

Originally Posted by jzemaxx

In an emaxx a 1521 1.5D will push you over 70+ mph on 8S. ;)

That's 8s though. I would not like to burn a new MMM!! If they're anything like they're little brother, 8s should be just fine. I have a feeling I'm going to see a lot of "MMM Overvoltage Testing" threads. Or so I hope.

[BL_RV0]

How about this setup?

Differential Ratio: 2.8461538461538463
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 50
Pinion Tooth Count: 10
Total Voltage: 22.2
Motor KV: 1900
Tire Diameter (inches): 6.5
Tire Ballooning (inches): 0
Motor Current Draw: 110
Motor coil Ω: 0.005
Spur/Pinion Ratio: 5 : 1
Total Ratio: 14.23077 : 1
Tire Circumference (inches): 20.42 inches (518.68 mm)
Total Motor Speed: 41135 RPM
Vehicle Speed: 55.9 mph (89.79 km/h)
Effective Speed Rate: 2.52 mph/V (4.04 kmh/V)
Estimated Adjusted Speed: 52 mph (83 km/h) - 8% loss
Effective KV Value: 1852.93
Motor Torque: 0.41 ft-lbs
Final Torque: 5.8 ft-lbs
Final Power: 2442 watts (3.3 HP)