Direct Drive to Diff E Revo Build

[sikeston34m]

Originally Posted by aqwut

What's Amps is that motor rated for?...

Here are the specs from the Manufacturer's website.


4120/14 Specifications
No. of cells 12 - 16
4 - 5 Li-Poly
RPM/V 660 RMP/V
Max. efficiency 85%
Max. efficiency current 20 - 40 A (>82%)
No load current / 10 V 2 A
Current capacity 55 A/60 s
Internal Resistance 41 mohm
Dimensions (diameter. x lenght) 49,8x55,5 mm
Shaft diameter 6 mm
Weight with cables 320 g

The addition of the cooling fan increases it's current handling ability I believe.

[johnrobholmes]

Outrunner ratings are near useless for car use I have found. On startup we burst a helluva lot more than the ratings, and our throttle use determines the average amp draw. The only numbers of interest to me are the Io, kv, and rpm ratings. Just because it is a 55a motor doesn't mean it wont pull 80 amps continuous or more when accelerating. The continuous ratings are more useful in planes where the prop load is very consistent. Prop to the continuous rating and the motor won't overheat.

I don't doubt you cut the ESC out with that motor. Im actually surprised you are getting such top speeds without overheating it.


I can fit 5 parallel strands of 24awg wire in the 30 series stator, with 4 winds per slot dLRK style. 8 turn with 5 strands.

[sikeston34m]

Originally Posted by johnrobholmes

Outrunner ratings are near useless for car use I have found. On startup we burst a helluva lot more than the ratings, and our throttle use determines the average amp draw. The only numbers of interest to me are the Io, kv, and rpm ratings. Just because it is a 55a motor doesn't mean it wont pull 80 amps continuous or more when accelerating. The continuous ratings are more useful in planes where the prop load is very consistent. Prop to the continuous rating and the motor won't overheat.

I don't doubt you cut the ESC out with that motor. Im actually surprised you are getting such top speeds without overheating it.


I can fit 5 parallel strands of 24awg wire in the 30 series stator, with 4 winds per slot dLRK style. 8 turn with 5 strands.

8 turns with 5 strands?

What do you estimate the kv as being on that with a Delta versus a Wye termination?

[johnrobholmes]

710vk with 8Y if the starting kv of 980 is correct. Luciens site states the 10D wind is 980 kv, don't know if they changed specs a bit since you got yours.


Now I know why they use 30awg. Getting just one strand of 24awg wire neat against the stator is a pain.

[johnrobholmes]

Just realized I was looking at the wrong motor specs, so the kv would be 604 for an 8Y wind.

[sikeston34m]

Originally Posted by johnrobholmes

Just realized I was looking at the wrong motor specs, so the kv would be 604 for an 8Y wind.

That's not a bad place to be IMO. So are you going to go with the Wye termination?

What truck are you planning on going with? The Revo?

I just did another run "test".

4S 10,000mah Lipo yields 52 minutes of pretty hard runtime.

40 minutes into the run, I thermaled the ESC again. This wasn't showing up with the lower capacity batteries. I think this Revo will be getting a Monster Pro for Christmas.

Maybe do a small Cap mod, then attach it to the Aluminum mounting plate with some thermal compound. That should work well for this system.

After the 52 minute run, temps are:

Motor = 125 degrees
ESC = 105 degrees
Batteries = 95 degrees

These Lipo's can give 100 amps continous with 150 amp Bursts. It shows in the performance too. I can tell there's alot less voltage sag under a load, especially compared to the 4000mah Lipo's.

After seeing how things went today with the different voltage levels, I prefer the 4S Lipo Best. With this motor, anything above that, it gets hard to control.

With this setup On 4S Lipo, You will find Nitro parts in it's droppings!

[sikeston34m]

Hey BL Revo, need to clear some messages out of your box. I can't send you a PM through there.

PM me your email address and I'll send you the videos.