Another overkill Truggy : MBX5T MMv3 1520 1Y 6S ;)

[nuz69]

Hello,
Here is finally my MBX5T converted with Mike's stuff. Happy to get the USPS postage today after a long wait and worry about customs ^^
The setup :

MMv3 1520 1Y 6S lipo 4000mAh 40C and 15/46 gearing (10/46 in the diffs)

Somes pictures :D







The motor mount and servo plate are beautiful , I set the punch control to 50% its already to powerfull, I just test it in my appartment and it appears to have a lot of torque. The motor drag is heavy due to long rotor, that mean TORQUE :D

I will test it tomorow, lets get to sleep and dream about brushless Tuggies :D :D

[ANGRY-ALIEN]

POWER!!! ... nice build man... Get some vids during test... that thing should be a handful...

[George16]

Very nice!!! There is no such thing as overkill.

[Semi Pro]

great looking truggy

[What's_nitro?]

Looks great man! I am concerned about the tape you put over the fan on the MMM. That seems counter-intuitive...? I'm sure you did it to keep dirt and things out, but with that much motor the fan may come in handy. :)

[nuz69]

Originally Posted by What's_nitro?

Looks great man! I am concerned about the tape you put over the fan on the MMM. That seems counter-intuitive...? I'm sure you did it to keep dirt and things out, but with that much motor the fan may come in handy. :)

I think not ! Geared for low 40 mph with 6S and 1600kV should mean lower amp draw than a classical 2200kV in 4S geared for same speed no ?
Yes its to prevent dust and thing to go the the fan, I had issue with blocked fan on my other MMv3 case :(.
I did the same for my inferno VE geared for 40mph in 4S and the fan rarely comes on, so I don't think there will be a problem...
Anyway, test in a few hours ^^ Hard to wait ;)

[nuz69]

Test completed !
Torque is insane obviously, but the chassis has no difficulty to handle it. Somes vids will come and will be more significant than long story, but it works great !
I was little disapointed by the temp at the end of the run : 135F motor (ambient temp 75 and i only drove under sun) and ESC Fan always on, but I completely closed my hull. Had the feeling that the ESC ran hot too although runtimes was great : 25 min on grass with 6S 4000mAh.
I will dry some air flow in my hull, reduce timing and punch control (current 50% and still hard wheelings !) and see what the temps are saying tonight...

[ANGRY-ALIEN]

Originally Posted by nuz69

Yes its to prevent dust and thing to go the the fan, I had issue with blocked fan on my other MMv3 case :(.

I was little disapointed by the temp at the end of the run : 135F motor (ambient temp 75 and i only drove under sun) and ESC Fan always on, but I completely closed my hull.

Hmmm... what kind of material are you using to cover the fan? It staying on for long durations could simply mean the airflow has been reduce dramatically and the fan is not
allowed to do it's job efficiently... If you need to reduce the amount of 'dirt' entering the fan, try something like a fine mesh... The temps for the motor aren't all that bad...

I found the below setup in the 1520 thread:

Differential Ratio: 4.6
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 15
Total Voltage: 22.2
Motor KV: 1600
Tire Diameter (inches): 5.65
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 3.07 : 1
Total Ratio: 14.10667 : 1
Tire Circumference (inches): 17.75 inches (450.85 mm)
Rollout: 1.26:1
Total Motor Speed: 35520 RPM
Vehicle Speed: 42.32 mph (67.99 km/h)
Effective KV Value: 1600
KT constant: 0.85 oz-in/A


Maybe if you try a smaller pinion (if it's available) you could see lower temps... ... at a full charge of 25.2 volts (approximately), a 14 tooth will yield 44.84 mph (72.03 km/h)
and 13 tooth will get you to 41.64 mph (66.88 km/h)


Don't forget the vids

Alien

[bruce750i]

Nice! That motor drag blows trying to put a pinion on when the flat spot is down. I run the same cells in (2)3s packs.

[nuz69]

It comes from my Tires !!! F.... ! So much time spent to glue them and they are TOTALLY unbalanced...... F.... F.... F.... !
So at high speed my motor works a lot to keep the speed against the heavy vibrations...
13 T pinions with 1520 1Y, thats just cant be!!!!! This motor with good balanced tires should be able to handle 22T pinions without issues... !
I will have to buy some new tires already glued and balanced... I am sure that is where I lost 20-30 degre on the motor...
Does somo one of you know some good one (tires) ?

[bruce750i]

They all need balancing, try to balance yours.
I take a rear dog bone out to let the tire spin freely on the axle. Spin it and let it stop on it's own to see how much and where to place some balancing weight on the inner wheel. I use lead tape from golf pro shops for weight.

[ANGRY-ALIEN]

Originally Posted by nuz69

13 T pinions with 1520 1Y, thats just cant be!!!!! This motor with good balanced tires should be able to handle 22T pinions without issues... !

Yeah... a 13 tooth is a little small... but I was really looking at the size Spur you're using... how will you be running the truck? speed runs, racing or just bashing?
The motor will definitely handle a 22 tooth, but you will still need a good run up space to get the 60's... Try a few pinions and see which one works the best for you.

Alien

[simplechamp]

Nice build. Get some heat shrink to clean up all that electrical tape!

[nuz69]

I tried with stock wheels, they are perfectly balanced.
Ambient temp 77F with sun, after the run (runtimes ~25-30min) 125F for the motor

[nuz69]

http://www.youtube.com/watch?v=bKltnX8V5JE

More to come ;)