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? :oh:

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

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.

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".:lol:

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. :lol:

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!:na:

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

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

I dont know what I will put it in. The only ride big enough is my x1 CR and I still haven't gotten satisfactory battery trays made up for that one yet. I am going to try a smaller outrunner in a wheely king rig first I think. I messed up the winding on my first try today, and I could fit another strand or two in as well.

i wouldnt get the 125b, it has the same overheating issues that the 80b does, unless you do the mod, but that voids your warranty.

I'm pushing alot of power through the 80b, and I know there is some seperation from the heat sink inside. I've had it apart a bunch of times.

The Monster Pro 125 has a higher rating because it has more FET's on the power card. This also means less resistence, so more power flow. :yes:

I really like the Quark line, mods or no mods.

I switched to 5 strands of 22 awg wire. Crikey it is hard to wind tight! Took more than an hour for one phase of the motor, only 2 left. With all this work I will leave all 6 ends open so I can switch from D to Y termination on the fly. Just so happens that a 8D on 3s is almost exactly the same rpm as an 8Y on 5s (wattage should be the same too). Time to test this kv VS startup torque thing.

I've been doing some more research about this on my own.

Delta has 1.72 times the kv as Wye Termination but draws 1.72 times the amps.

Wye has 1.72 times the torque as Delta, but draws 1.72 times less amps.

SO, correct me if I'm wrong, but to make the Wye termination put out the same wattage and KV, You must use 1.72 less winds on the stator.

There are two big advantages of the Wye termination IMO.

1. More Torque! 1.72 times as much torque. I think this is mainly due to the fact that 8 magnets/poles are in use at any given time, rather than 4 magnets/poles on the Delta.

2. More EFM feedback to the ESC at lower rpm's. I just discovered this today as I was reading about this. The Wye should run/start MUCH better in a Car/Truck Application.

I'm thinking about taking a short cut to the entire winding/experimenting thing. AXI motors says "If you have a custom motor in mind, do not hesitate to contact us."

I think I'm going to ask them if they can do a custom wind for me. I want a 4130/8 with a Wye Termination. I want to shoot for 700kv and with a Wye Termination, this should be a BEAST! :yes:

That is correct, a delta terminated motor needs 1.72x the winds to match a Wye terminated motors KV. The D termination has less resistance since there are two parallel current paths in any phase.

I think you are getting a bit ahead of yourself on the torque though. While yes you will have 1.72x the torque with a Wye termination (per amp), the amp draw will go down. If you don't change your voltage the torque (and wattage) will actually be lower since torque and amp draw are directly proportional. If you volt back up to the same motor speed your torque will again be the same, but at a lower amp draw since the kt is of higher value with a lower kv motor. A 1200 watt motor is a 1200 watt motor, and the torque curve is almost perfectly linear for a permanent magnet motor no matter what the wind or termination.


The increase in EFM feedback should be correct though, plus higher voltage motors give better feedback anyway. Although the motor doesn't have higher torque, the ESC should see the motor better in effect making more efficient use of the torque.


It really wouldn't be hard to take a motor apart and just change the termination.

I feel like there must be a good torque bonus if only based on the fact that it's pulling on 8 magnets with each phase instead of 4.

Yes motor timing will be more accurate especially at low speeds.

I've thought about taking one apart and changing the termination, but let's look at an example.

The 4120/14 that I'm running is 660kv. By using the same 14 turn winding and changing the termination, I'm cutting the kv to 384kv. Even though torque would be increased by 1.72 times, the 384 kv isn't enough to do the trick. Unless I wanna go HV. Hmmmmmmm.........there's an idea!

The is where more strands and less turns comes in.

I plan on consulting with the winding guys at AXI about this. Let's see what they say. :yes:

John, there is alot of valuable motor building information here.

Just trying to pass along some tools that I plan on using.

http://www.bavaria-direct.co.za:80/m...motor_info.htm

I don't know if theory alone can explain this well, there are so many variables. When any phase is excited, delta energizes all three coils at a time whereas Wye only excites two. If kv is the same between termination styles the amp draw will be the same, and since kt and amp draw will be the same the motor torque will also be the same.


Change the magnet count or stator count- motor power will change. Change the size of the motor, motor power will change. Change the winding of the motor, motor power only changes in respect to voltage.

One thing that I thought was very interesting is at the bottom of that page. It's how to figure the kv of any motor that's already built.

"Drive your motor with a power drill.
Measure RPM and voltage generated.

Kv = RPM / voltage"

I spun the 4130 at 930rpm with a drill. It was feeding 2.9 volts into a volt meter on the AC scale.

930rpm/2.9volts= 320kv

Pretty close to the factory rating of 305kv! Which maybe with the load of the motor, the drill wasn't quite spinning at 930rpm. I think this is a good quick method though.

The generator method gives you the kv with consideration to efficiency losses in the motor. Factories do not always do this, and it could explain the small difference you found. Pretty darn close though.

Yes, there are many variables.

Total Power output also changes in respect to Amp draw. Total watts of power.

The way I understand it, on a 12 pole motor:

A Delta Winding has 4 poles energized at a time.

A Wye Winding has 8 poles energized at a time. but they are 4 x 2. 4 sets of 2. The amp draw is lower for identical turns because the pairs of windings are in series to each other. This drops the amp draw by 1.73 times along with the kv. but raises the torque by 1.73 times.

I guess what I'm really wondering is, if we drop turns to raise the kv back up in a wye winding, will we retain the added torque bonus along with the improved EMF feedback?

Here's what Lucien had to say about this when we were discussing a high kv wind on a 4045 Scorpion motor. (note: 700kv wye wind will be easier on a 4130)

Here's what I asked him:
"Would it be possible to wind a 4045 to around 800kv using larger diameter wire, such as 22 awg, using a wye termination for a 1.73 torque bonus? (Minimize copper losses and keep operating temps to a minimum?) I noticed that with a wye termination, it uses 8 magnets, 8 poles at any given time. I'm not too concerned about amp draw or total efficiency at this point. I'm just looking to have some fun and learn more about 3 phase windings and how they perform."

Here's his answer:

"It would be very tough to wind a 4045 with a Kv of 800, especially with a Wye wind. THe current 4045-10 has a Kv of 360, the 4045-12 has a Kv of 315, and the 4045-17 has a Kv of 270. These are Delta wind motors, so if you switch to a Wye, the Kv will be lowered by a factor of 1.73. A 4-turn Delta would have a Kv of about 800, but you would have to wind about 50 parallel strands to get enough copper in the slots.

The larger motors are made to run on 10-12 Li-Po cells to be able to get enough power to run the motor, and that is why they have a much lower Kv.

Think that over and let me know what you think."

I keep notes on all the information I've collected. :lol:

Now keep in mind that the 50 strands that he is referring to is 31awg. Total Cross Section area of the wind and total resistence is what we need to look at. In other words, we can use a much larger Ga. wire and eliminate the whole 50 strands thing.

I'm sure the end product of what I'm trying to put together will DEFINATELY be a high amp draw motor. But that's ok, that's what I want. Total Watts is Total power.

I want to run this on 4S Lipo or more. It's ok if it draws 100 to 150 amps continous.

I asked AXI about motor kits for the people who want to wind their own motors. Maybe they have those.

If you raised the kv back up to negate the wye termination, you would indeed lose the torque bonus.

Kt = 1352.4 / Kv By this formula the torque constant and kv are directly related for any and all electric motors. Like I said before, if the overall construction of the motor is not changed the power of the motor wont change. Different terminations or winds only change the voltage and amperage that the motor will produce said power. The torque curve won't change, the wattage wont change, the motor is still the same motor.

I have fought this issue with guys at RCC for a while now. People thing a 65t motor will produce more torque than a 55t motor. Geared for the same wheelspeed they will produce the same torque and power if the rpm of the motor is also the same. This means a different voltage for the two setups. On the flipside, if gearing and voltage is held constant the 55t will have more power since it spins faster and has a higher amp draw. A third example is when wheelspeed is kept the same through different gearing with fixed voltage. A 35t motor on 3s lipo geared way down will have a ton more power than a 65t on 3s lipo geared for the same wheelspeed. Lower turns, but more torque through amperage and gearing. In your case you cannot change the gearing except with tire changes, so we have one less variable to deal with.

Between two identical motors with different winding:
Same gearing, same wheelspeed (indicates same rpm at motor), different voltages to hit said rpm. If the vehicle hits 60mph it will take the same wattage no matter what the motor if vehicle weight is constant. Same power, just at different voltages.


The aspect we are really going for is a better low speed commutation of the motor, correct?. Although the motor will have the same performance capability no matter what wind or termination, the ESC might do better with certain ones.


The 4045 is a huge motor. Getting a kv so high will be very tricky.

I understand what you're saying where different winds of brushed inrunner motors are concerned and I aggree with you completely.

Outrunner motors are different creatures with more magnets floating around. In the Delta, when the 4 magnets are being attracted to their energized poles, the other 10 magnets are just waiting their turn to do their work.

What makes me wonder, 8 magnets versus 4? My theory is, the 8 will win the tug of war.

If I'm wrong, then I just am. But if I'm right, why aren't they building them this way? For one thing, heat buildup. Wouldn't the heat be 1.73 times greater also? I'm willing to try this, since the motor in the Revo has ran so cool.

But yes, even if it's just the better low speed commutation of the motor. That would definately be a benefit worth pursuing.:yes:

They act no different than any other motor type. They are just permanent magnet motor and abide by the same rules as inrunners and brushed motors alike.

Even if one of us is wrong in our assumptions, it is still a great conversation! :lol: Until we get some real quantitative testing done we can't do much more than chat about it anyway.

Yes it is a GREAT conversation. You bring things to the forefront that I haven't considered.

I would like to stick with the AXI motor because of the cooling fan that I've mounted to the rear of it. Hopefully, AXI will answer my email soon.

Even if I can just get a Delta wound 4130 that makes 700kv, it will outperform this 4120 since it's stator/magnets are 10mm longer. It will make more torque.

The Revo runs well. It's powerful and efficient. I'm happy with top speeds and even the low speed driveability. I just want some more torque with the same top speeds. Along with the extra torque will come more acceleration.

With the 4S 5000mah Lipos, RTR weight is 10lbs 3 ounces.

I think more outrunner power can be had on the 4S setup with a custom higher kv wind on the 4130 motor.

The 4130 motor would match the top speed of the 4120, possibly even more, if I had the ESC and Lipo's to put it on 8S to 10S. But even then, we are talking more weight.

I'm really considering going with the Quark 125 amp Monster Pro. I should see a performance improvement because of the increased current handling ability. It also has less resistence accross it's power board.:yes:

I can barely imagine what kind of power a 4030 will put down. It will be interesting to see if the gearing or rollout threshold for startup will can be changed much with the extra motor size. Getting any more speed from your revo as-is takes a taller tire,hotter wind motor, or higher voltage. I really think the simplicity will help understand the limits of sensorless motor control.

I think I am right at the threshold for startup with the 4120.

It was surprising to see that the 4130 was only generating 2.9 volts at 930 rpm. I wonder what the lower and upper limits of the EMF feedback "window" really is?

I'm sure the design of the ESC has some reasoning in it that matches most setups out there. There is a resistor in each of the 3 lines on the EMF feedback leads going to the brain board. I'm sure those are there to raise the upper limit of the EMF "window", but it also raises the lower limit that can be seen by the ESC. I wonder what would happen if those were removed? I believe they traded some "lower" to increase voltage operating range. The Quark tends to cog more on fresh fully charged 6S Lipo. I'm sure it has to do with this. Removing those would probably make for better startups, but also might lower the voltage operating range to perhaps 4S or 5S.

I have a Quark 125 Monster Pro on the way now. Once it gets here, I may try to bypass those resistors on my 80 amp ESC as a test. Do something that is reversible just to see. I need to ask Griffin about this.

Vehicle weight has alot to do with this also. The ESC blindly (no EMF feedback) sends a "kick in the pants" to the motor for startup. If vehicle weight or gearing is so great, that the motor doesn't give the vehicle enough movement to get some EFM return, the ESC is "lost" as to armature position. This is when cogging occurs.

The 4130 did startup better than the 4120, but the top speed wasn't there so I switched. This leads me to believe that kv and stator length has something to do with this.

Aaaah, look at this.

"Kv = RPM / voltage"

I spun the 4130 at 930rpm with a drill. It was feeding 2.9 volts into a volt meter on the AC scale.

930rpm/2.9volts= 320kv"

With the higher kv of 660, using this formula, the 4120 at 930rpm is only going to generate 1.4 volts. :surprised:

The first EMF pulses must be VERY small and hard to see. Longer stator/magnets/winding changes that.

Hmmmm............This is where experimenting with different winding configurations could pay off. :yes:

AXI emailed me back!

"both ways are possible to provide you with set of parts for this motor. This we make really rare but in case you have it for some special application it is possible. Or if you tell use the winding we can make for you custom made winding."

What wye wind should I get to make 700kv?

Here's what I wrote them back.

"With a Wye wind, the torque is 1.73 times greater than the Delta wind but the kv is 1.73 times lower. If we negate the kv loss with fewer turns, will the torque bonus still be there?

Excellant! How much for the custom wind 4130? How much will the kit be?"

This should be interesting! :yes:

get a vid when shes done!

Well the custom wind from the manufacturer is pretty much out of the picture. I can buy two regular motors for what they want for that.:surprised:

I have a second 4130/20 here that I can use to experiment with different windings. But how do I get this stator off the bearing holder?

Hmmm, I wonder if I could trim the stationary endbell down to allow enough room to do the winding and make the terminations?

I was thinking about modifying a pair of needle nose pliers to aid me in this. Grind the teeth off the jaws, then wrap them with black tape. I know I can't tear the insulation on the winding wire as this will create shorts.

Get some kits from Lucien. Although he doesn't have any 40 series kits yet, I know I could get just the stators and bearing tubes from him. Then you could just swap out the bell from stator to stator and save some cash on buying magnets. You would need to use a specialized bearing puller to get the stator off the bearing tube otherwise.

I just ordered a 500 foot roll of 22 Ga winding wire that's rated at 200C.

With this first round, I'm gonna try to rewind this second 4130 that I have. I would rather stick with AXI to start with, because I don't know how hot this is going to run. The cooling fan will help with that since it moves alot of air.

I'm thinking about a 6 or 7 turn wye termination with as many strands of 22Ga that will fit. Once wound, I can do the spin voltage test to get a close approximation of the kv for the wind.

I intend to wind it just like this.
http://i160.photobucket.com/albums/t...tarWinding.jpg

Any thoughts?

Check out this Wye Wind on a Scorpion Motor.

It's in German, I wish I knew what they were saying about it.

http://www.powercroco.de/12N14P3032scorpionalt.html

If you have 14 magnets you have to stick with LRK or dLRK. http://www.southernsoaringclub.org.za/

Where did you find the wire? I need some with a coating I can count on.

Is there a different magnet arrangement for this 12 pole wind? Thanks for the website, I'll check it out.

I got a 500ft spool of 200C from this Ebay seller. Looks like the last 500ft spool they had listed. I'm sure if you drop them a line, they have more.

http://search.ebay.com/_W0QQsassZswordandtreasure

OK, Now I THINK I understand! :lol:

The winding pattern I displayed earlier is for a 12N16P configuration. 16 magnets.

I discovered this after ALOT of digging and research. Here's the wind that I believe I need to go with. Please correct me if I'm wrong.
http://i160.photobucket.com/albums/t...ermination.gif
The Wye termination will connect the ends marked "ende"

I also did some reading through a translator about the scorpion 3032 that this german guy wound. He has test results displayed there.

It is an 8 turn with a wye connection. 550kv. I'm sure that is a torque monster. :yes:

Yeah, that is how I am doing mine. If you have more room between the stator and back plate of the can LRK winding works, but most 12 slot hobby motors are meant to be wound dLRK like that pic shows. The scorpion motors can't be wound LRK, not enough room lengthwise.

The powercroco site is awesome, I wish my german was better.

I wonder what size wire he is using. He does it all with only one strand! :surprised:

http://babelfish.altavista.com/ is a good translator.

Just copy and post the PowerCroco url to it and you can navigate the website in English.

Pretty cool :yes:

I thought something looked funny about the german guys wind in thinking it was a wye termination.

After reading some more, it's a Delta winding. He just made the connection across the stator by soldering.

I'm waiting on my 200C 22Ga. Winding Wire to come in, looks like it's going to be early part of next week. *sigh* The AXI 4130 is just sitting here waiting.

In the meantime, I have spotted a couple of motors to practice winding on. They are outrunner motors that I've used with the E maxx.

One is the 650kv that I do the E maxx outrunner conversion with. The other is a discontinued Lightning 600 Helicopter motor that I was running an E maxx with.

I just unwound a Lightning 600 stator. It was wound Delta DLRK style with 20 strands at 5 turns per pole.

The stator on this motor is 35mm in diameter and 30mm long. Each pole was really full wound this way. It's a little puzzling to me because this motor was rated at 715kv. Being a 5 turn motor, It seems like the kv rating would have been much higher than this.

@JohnRob - Did you get your wire ordered?

I haven't ordered wire yet, and I still have one last phase to wind on my 3032. I fell on my head monday so I can't really do anything if front of me for very long periods of time yet.


the kv on that 3530 seems about right. 5 turn delta, big and long stator. The bigger or longer it gets the slower the motor will spin with any given wind count and termination.

OMG, Are you ok? I hope so.

With the 4130, I'm thinking about a 4 turn Wye with the 22Ga. wire. I'm gonna practice wind the 3530 and try it out in the E maxx a couple of times first. Get some trial and error testing in so I can make a more educated guess at knowing what the 4130 will do with what wind beforehand.

The flip side to the bigger and longer the stator is, the slower it will go, is the more torque it will have. :yes:

The mail lady came today bearing gifts. The Revo Will get the ESC and the BEC, the fan motor cooler is for a Electrifly Ammo 36-56-2600kv inrunner motor that I want to try on the E maxx. I know it's gonna run hot with 20/76 gearing on 4S lipo, but the fan should help.

http://i160.photobucket.com/albums/t...m/DSC06677.jpg