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Rewind HobbyKing cf2812 motor

Foam Addict

Squirrel member
At the cost of a fatherly lecture and a burnt out phase, I figured out how to get the reading: 1 volt over one phase. Unfortunately I plugged in the wrong mess of batteries I had dumped on my work bench, and got 50.93 amps at 9.03 volts. Oh well, it only took 3 min to rewind the phase.
 

jetpackninja

More combat please...
Mentor
Love these little red motors.
Here's what I'm getting from the stock configuration:

IMG_20140708_214143_922.jpg

And this is what I get from 8 turns of the MicroDan wire.
This should give a pretty decent performance boost to my rebuilt Assassin project!

IMG_20140708_215559_809.jpg
 

RAM

Posted a thousand or more times
Am I reading that right? You went from 212 watts to 400 watts??

I just purchased a meter like that but haven't had a chance to set it up yet.

Is the red motor the Emax?? Have one of those too.

If it is the Emax, what size of MicroDan wire did you use??

thx
 

jetpackninja

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Yes. A significant power increase. But also went up in amp draw, from 17 amps to 32.
The Emax cf2812 is the motor discussed here.
8 turns of 24 guage MicroDan wire.

6 Minutes of spirited flying brings the motor down pretty warm, may try with a 6x4 prop.
 

jetpackninja

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The next weakest link with these motors is the bearings.
I have a couple of these that I believe are having bearing related issues and I want to replace them before they disintegrate.
Sourcing some now and will post the links if I'm happy with them.
 

RAM

Posted a thousand or more times
Yes. A significant power increase. But also went up in amp draw, from 17 amps to 32.
The Emax cf2812 is the motor discussed here.
8 turns of 24 guage MicroDan wire.

6 Minutes of spirited flying brings the motor down pretty warm, may try with a 6x4 prop.
Thanks for the info. I'm going to order some microdan.

Also, will be interesting if you find a good replacement bearing. Good luck.
 

jetpackninja

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Bearings are 3x7x3 (front smaller bearing) and 3x8x4 (rear bearing) (id,od,width).
www.advantageracingproducts.com is the place I ordered from.
Had some issues with the website but was able to get it done with some help from one of their friendly sales people.
Will update again when the bearings arrive.
 

jetpackninja

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The bearings from Advantage Racing arrived and appear to be good quality.
I think I'm just going to replace the bearings as SOP when I take the time to rewind.
One of the gotchas with these motors are that the bearing sizes and motor mount size has changed from time to time.
If you get one of the older motors, the bearings may be differently sized.
Time to go have fun for Saturday flying tomorrow!
 

jetpackninja

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A couple of snaps.
My latest rewind mounted on a CrashTestHobby Scythe.
9 turns. Upgraded bearings. Should keep me happy for a while on the Scythe.
It already felt very fast on the stock little red motor.
Should be interesting.
IMG_20140721_214007_444.jpg
IMG_20140721_214038_479.jpg
 
Windings

Im new to rewinding. I just rewound a 2822 with 15 turns of I believe 26 gauge wire. It starts up and runs wide open just fine but only show about 7 amps on my meter. does the larger number of winds decreas the amp draw? If I go with fewer winds does it increase the Kv and amps along with added heat. I can run the thing wide open with a 9x6 or 10x5 on the bench and it barely gets warm.
 
I know this is a old thread, but Im just learning about rewinding brushless and found it.
I have a near dead 2822 and a few new 2812s I found the thrust on my versa wing is just barley enough to keep it flying, but nothing for real punch outs.
that pic of the watt meter 200w - 400w thats a huge increase, what wiring config was used, and what prop ?
 

jetpackninja

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Yes! Got the combat wings going. A friend who moved out of the neighborhood gifted me a small Edge 540 plane and I got that going.
Ninja Jr built a baby blender and I liked his so much I built one too. So winter is approaching but still mange to hit some nice days out here and there :) Sorry I didn't see your post sooner!
 

jetpackninja

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Oh, to keep on topic, I just got an update and my friend Dan still flies his combat-corro f22s with one of the first few motors that I rewound :)
And to jump back off topic, blenders :)
bb1.jpg bb2.jpg bb3.jpg bb4.jpg
 

jetpackninja

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Welcome back stranger! Winding our own sounds interesting. You been flying lately?
Yes.
Got AMA.
Joined a local club.
Flying whenever we can.
Just rebuilt one of my original rewinds and haven't had an opportunity to test it yet.
I intentionally bashed and overheated this motor with back to back runs in 100 degree sunshine.
I wasn't nice to it, eventually burnt a phase.
We'll see how it goes ;)