Direct Drive to Diff E Revo Build

[johnrobholmes]

I have the permatex green, didn't realize it was medium penetrating. I will probably stick with epoxy then. Only place I know that carries loctite brand would be online retailers.


The conversion from Wye to Delta is 1.7 winds, so a 10 turn Delta is equivalent to a 10/1.7 turn Wye - almost 6 turns. This keeps kv constant. The conversion from a 10 turn D at 980kv to a 6 turn Y is as follows: [10T/1.7=5.88T] [980kv x (5.88T/6T)] = 961kv with a 6T Y termination. Substituting the 6 for any other wind count will give kv with Y termination.

Looks like the 3032 with a 6Y on 4s lipo will be pushing it pretty hard. 15k rpm, don't know how well the ring bearing will take it.


One thing I didn't think of for startup is the length of wire and the inductance on a coil. The ESC will sense a higher strand count coil better, so maybe this could cause lower kv motors to start up better. Not a product of motor torque as much as the ESCs increased ability to see a higher wind motors position? The issue with total motor power always gets me when thinking of startup. To me any 1000watt motor should start up the same unless the wind count is on the extreme end of things. Probably not the most accurate assumption.

[johnrobholmes]

Oh yes, the scorpion stators are keyed. If you had the means to mill a keyway into the bearing tube you could easily have a removable stator.

[sikeston34m]

Originally Posted by johnrobholmes

I have the permatex green, didn't realize it was medium penetrating. I will probably stick with epoxy then. Only place I know that carries loctite brand would be online retailers.


The conversion from Wye to Delta is 1.7 winds, so a 10 turn Delta is equivalent to a 10/1.7 turn Wye - almost 6 turns. This keeps kv constant. The conversion from a 10 turn D at 980kv to a 6 turn Y is as follows: [10T/1.7=5.88T] [980kv x (5.88T/6T)] = 961kv with a 6T Y termination. Substituting the 6 for any other wind count will give kv with Y termination.

Looks like the 3032 with a 6Y on 4s lipo will be pushing it pretty hard. 15k rpm, don't know how well the ring bearing will take it.


One thing I didn't think of for startup is the length of wire and the inductance on a coil. The ESC will sense a higher strand count coil better, so maybe this could cause lower kv motors to start up better. Not a product of motor torque as much as the ESCs increased ability to see a higher wind motors position? The issue with total motor power always gets me when thinking of startup. To me any 1000watt motor should start up the same unless the wind count is on the extreme end of things. Probably not the most accurate assumption.

I ran the 3032/10 in an E maxx. It was running pretty warm. It would start good and had great acceleration though. The 3032/10 is 823kv. You might want to back down from the 980kv some.

[sikeston34m]

The 5S1P 4000mah run lasted a little less than 20 minutes. These are older 10C cells. I've ran them pretty hard all summer in the E maxx, so I doubt they are quite putting out 4000mah anymore. I bought these batteries in Feb.

Battery temps are 120 degrees. Motor is at 100 degrees and the ESC is 115 degrees. All still well within range.

The 5S Lipo setup runs exactly like the 6S1P A123 setup. I couldn't really tell any difference as far as performance goes.

I'll try 6S 4000mah Lipo next. We should see some real gains then.

[aqwut]

Originally Posted by sikeston34m

The 5S1P 4000mah run lasted a little less than 20 minutes. These are older 10C cells. I've ran them pretty hard all summer in the E maxx, so I doubt they are quite putting out 4000mah anymore. I bought these batteries in Feb.

Battery temps are 120 degrees. Motor is at 100 degrees and the ESC is 115 degrees. All still well within range.

The 5S Lipo setup runs exactly like the 6S1P A123 setup. I couldn't really tell any difference as far as performance goes.

I'll try 6S 4000mah Lipo next. We should see some real gains then.

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

[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?

[sikeston34m]

The 6S 4000mah Lipo run lasted 22 minutes. Motor is at 105 degrees. Batteries are at 102 degrees and the ESC is at 115 degrees.

I think the Monster Pro 125 would suit the 6S setup better. I believe I seen the 80amp thermal while running WOT in the grass. First time for this, I was a little shocked and puzzled.

This is harder to control. Severe Tire Swelling and a large increase in Top Speed. I believe we have surpassed the 60 mph mark. I was running on the outer road by the interstate. I can almost keep up with traffic!

It will wheelie at speed now, especially in the grass. It will spin all 4 of them on the asphalt.

I'm very impressed with the motor temps. The fan seems to be working to keep temps low. Seeing the fan as an option is alot of the reason why I decided to go with AXI. I think this motor can do well even on 7S Lipo.

I love the Revo. It handles so much better than the E maxx especially at high speed. The suspension is so much better.