Need a Huge 63-74 Outrunner Rewound

[Takedown]

Just as the title says... I will be ordering this outrunner tommoro for my warhead- http://www.hobbycity.com/hobbycity/s...idProduct=3890

Problem is the kv is a little to low. I would like to get it rewound to have around 400-500kv or so but I cant find anyone willing to do it, "including sikeston".

Is their anybody that can help me out with this?

[What's_nitro?]

Is there a machine shop around you that could handle it? Also, why don't you want to use a higher voltage to run it as-is? Do you already have the rest of the power system ready?

[Takedown]

I really dont want to buy another battery. I like my FlightPower 3200mah 30-60c 5s alot! I just need to get it rewound... Thats all.

[What's_nitro?]

I see. Well... You wouldn't need to buy a different battery, just buy another FP 5s 3200. You're looking to have it rewound to about twice the kV, so twice the voltage would run it equally well if not better. I don't know what it would cost to have it rewound compared to the cost of another battery. I suppose a big factor is if you have the ESC yet.

[Takedown]

Ya I have the ESC prepped and ready to be ran with this brick. I would much rather run just my 5s because I really dont have a great amount of money right now to be dumping into my warhead project.

[What's_nitro?]

Have you considered doing it yourself? I imagine the stator is pretty big inside that motor so it may not be that hard to do.

Now, would it be half as many turns for twice the kV, and just use a larger wire? Or is it not that simple?

[Takedown]

Originally Posted by What's_nitro?

Have you considered doing it yourself? I imagine the stator is pretty big inside that motor so it may not be that hard to do.

Now, would it be half as many turns for twice the kV, and just use a larger wire? Or is it not that simple?

Ill be using 22awg wire found in nice 1/10 540 racing motors like sike did. It really doesnt matter what kv range Ill be getting after its rewound as long as its better than what it is right now. If thats the case then Ill try my hardest and maybe Ill have you guys guide me threw this step by step. I really want to pull some power out of my e-warhead conversion and this looks like the perfect motor. Just to low of kv... I also have to grind both ends of the shaft to 8mm to fit the couplers.

[johnrobholmes]

Winding isn't too hard, but speeding that outrunner up might cause problems. What target RPM are you trying to get it to hit, and what is the magnet/stator count?

For small wind changes, the kV is tied to winding in a semi linear fashion. It is really complicated to actually calculate them off the cuff though.

Taken from Reliance.com, but there are other forces to be accounted for.

This equation can be further developed to obtain the voltage for movement of a conductor at constant velocity through a uniform magnetic field:
E = NBLv sin P x 10^-8

where:

E = voltage
N = number of turns
B = flux density in lines per square inch
L = length of the conductor in inches
v = velocity in inches per second
P = the angle between the conductor and flux field



You do realize you just ordered a 2 pound motor right? :D

[Takedown]

Originally Posted by johnrobholmes

Winding isn't too hard, but speeding that outrunner up might cause problems. What target RPM are you trying to get it to hit, and what is the magnet/stator count?

For small wind changes, the kV is tied to winding in a semi linear fashion. It is really complicated to actually calculate them off the cuff though.

Taken from Reliance.com, but there are other forces to be accounted for.

This equation can be further developed to obtain the voltage for movement of a conductor at constant velocity through a uniform magnetic field:
E = NBLv sin P x 10^-8

where:

E = voltage
N = number of turns
B = flux density in lines per square inch
L = length of the conductor in inches
v = velocity in inches per second
P = the angle between the conductor and flux field



You do realize you just ordered a 2 pound motor right? :D

This is why I want someone else to rewind it for me. Im horrible at math and im scared I'll screw up. Oh and no I didnt order it yet. Most likely will though. The motor rpm I want is around 600kv or so... Its a 14 pole, 52/40 size stator.

[johnrobholmes]

If you want 500 to 600KV, just get a motor that is in that target range. A 16 ounce motor would be plenty, even a 10 ounce outrunner is a lot for a vehicle.

What voltage do you plan to use?

[Takedown]

Plan to use 5s. I had a 16oz 50-55 600kv outrunner but it got to warm for my likings.

[lincpimp]

Your motor brand choice is most likely the cause of the heat. Buy an axi 4120 in the correct kv and stick with that. Plus your battery is only going to give so much, so a larger motor may over draw the battery. That 3200 will give a max of 96 amps, and with a lower capacity it will not do that for long. I would stick to a smaller motor, and a better built one too.

Try this motor out, I think this is what sike uses in his revo: http://www3.towerhobbies.com/cgi-bin...?&I=LXPPX8&P=7

[Takedown]

No I mean the 50-55 600kv only got up to about 120 degrees after a good run in the warhead but didnt have enough power for me. I want more power and thats were the 63-74 comes in. I cant find anything with around 600kv that has the stator size of 50/30 or more.

[lincpimp]

Originally Posted by Takedown

No I mean the 50-55 600kv only got up to about 120 degrees after a good run in the warhead but didnt have enough power for me. I want more power and thats were the 63-74 comes in. I cant find anything with around 600kv that has the stator size of 50/30 or more.

In that case it may have been either the batteries or the esc. A larger motor will have more torque, but not necessarily more power. Plus spinning a larger stator will require more power as well. I would try an axi, it will be more powerful than you think.

[sikeston34m]

Hi Takedown,

I just got your PM then I noticed your thread. I think I'll just respond here.

You're right. I'm not really interested in rewinding motors for people. For me, I find it fairly difficult. It's not so hard to actually rewind an outrunner, provided that NO mistakes are made.

What I found to be one of the hardest things, is removing the stator from a motor that is already built. Some Manufacturers use Adhesives similiar to Loctite that require ALOT of heat before they even think about letting go. I baked one in the oven at 500 degrees before I could get the stator off. This melted all the wires together and removed most of the protective coating from the stator.

If you are interested in rewinding a few motors yourself, I do have detailed instructions and diagrams on either DLRK style that you want to go with. Both in Delta Termination and Wye Termination.

On what influences KV in a motor. The larger the Diameter of the stator and the longer the stator, both tend to produce a lower kv motor.

To compensate for this, fewer turns need to be used. This opens up room for more parrallel strands of winding wire to be used. Example: If you remove 10 strands at 20 turns then you can go back using the same Ga. wire for 10 turns using 20 strands.

The goal should be to get the stator poles as full as possible. This makes for a motor that is most efficient and results in cooler temps with less copper loss.

By rewinding, a motor can be changed to perform very different than it once did, BUT.........you also need to consider what you want it to be, then shoot for that.

In raising the kv, using fewer turns and more strands, the internal resistence of the winding is greatly reduced creating a larger load for the ESC to handle.

To achieve a 600kv rating with a 52/40 sized stator is going to be pretty hard. The end result will be beyond your battery's discharge capability and probably beyond your ESC's ability to deliver what it wants. That's a huge motor man.

A custom AXI 4130 using 6 strands of 22Ga. wire and 4 turns makes for a motor that is in the 500 - 550 kv range. This motor has the Wye termination.

The Wye termination makes 1.73 times the torque that a Delta wind does AND makes 1.73 times LESS KV. The amp draw is also 1.73 times LESS than a Delta Wind with the same amount of turns. The Wye also starts better and runs cooler in my opinion. With that being said, this is why I decided to create a 4 turn motor.

It is a hoss! The starting amperage is huge also. Toward the end of the charge, the ESC is getting on the LVC too soon because of the huge amperage (125 - 150amps!) it takes to start this bad boy directly driving the diffs. Consider all of this before you put alot of time into something that isn't going to work.

The 52/40 size stator it TOO big for what you're trying to do. (+ it will explode the diffs). I'm with Linc on this one. Choose something smaller. AXI does make GREAT quality. They use Neo magnets, which is very important when you put one outrunner up against another to compare.

Alot of companies don't use Neo Magnets. This cuts their performance and makes them run hotter.

In cooling this type of setup, think Aluminum for mounts and airflow. I like AXI also because they sell a bolt on fan for "extreme" applications.