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        Discussion Emax 2210/30 excavation

#1 zeroback Jan 12, 2013 04:34 AM

Emax 2210/30 excavation
 
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I bought this little Emax 2210/30 a while back for testing and an then an autopsy.The motors literature advertises it as machine wound I was curios as to the pros and cons of "machine winding". http://www.headsuprc.com/servlet/the...ushless/Detail I first bench tested this motor and it squeaked buy meeting the advertised specs.
In a nut shell, 14T delta 3 strands 2mm/.008" (bare) .22/.009 1w/coating 64 and 3/8" long. Although one phase had a broken conductor near the center of the wind. No glue was used to secure the windings so the unwinding was a breeze. Although the lack of glue on the wires has visible consequences.

Previous reviews of this motor in it's 1400Kv form clearly indicated marketing license was used when creating the advertised specs. At $25.00 bucks a copy it wasn't a great value. .
The machine winding did a perfect turn count on each arm BUT there is allot of empty space on the stator.

#2 wim5150 Jan 12, 2013 07:02 AM

zero please post info and test results on the re-wind.

#3 jackerbes Jan 12, 2013 09:26 AM

Nice autopsy!

Thanks for that. That motor was the 2nd motor I ever rewound but I did not do as well or was not as lucky as you in getting the original windings off. I would up with a bare or any coatings stator and a stack of loose laminations. You can see the details here:

http://www.rcgroups.com/forums/showthread.php?t=1248742

Good luck with it!

Jack

#4 zeroback Jan 12, 2013 09:43 AM

I think this a version/generation two Emax . Jack was the motor you did machine wound?
My plan is to wind it LRK with a Kv around 920. The last 2 ( LRK and a dLRK 2215) motors I wound using STC came out quite acceptable power wise but were higher or lower. Kv than I calculated, or tried to predict I may have messed up. My 6T dLRK star 2215 came out around 680Kv, takes a 12X3.8 to load to 200 watts good thrust but lacks snappy throttle response. I was aiming for 1000Kv. The LRK was allot closer to the 1K mark coming in at 1040Kv. Little to fast for my target 11"SF prop but it swings a 10X4.7 with a vengeance. I plan on doing a side by side with the 2215's against stock wind. Just need the rainy windy day and a few hours.
I plan on posting my math before winding so if I get it wrong someone may point it out. When it's all together I'll test it and post the results.

#5 jackerbes Jan 12, 2013 06:49 PM

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Quote:

Originally Posted by zeroback (Post 23790910)
I think this a version/generation two Emax . Jack was the motor you did machine wound?

No I think not. It was a mess of epoxy saturated windings made it a monster to strip. In the end it spent several days soaking immersed in Acetone and that is what removed the stator coating and loosened the stator into a stack of loose laminations.

In the end the motor ran OK and I was much older and smarter about almost everything we do to rewind a motor. If there was any part of the process that was not done wrong once or twice I would be surprised. But the guys here gave me a lot of good advice and it was a good learning process for me.

The motor was laid aside eventually and I think it had suffered from my efforts for long enough. I think the magnets might have been getting puny and the stack of not properly glued together laminations were combining to make it not worth any more work.

Quote:

My plan is to wind it LRK with a Kv around 920. The last 2 ( LRK and a dLRK 2215) motors I wound using STC came out quite acceptable power wise but were higher or lower. Kv than I calculated, or tried to predict I may have messed up. My 6T dLRK star 2215 came out around 680Kv, takes a 12X3.8 to load to 200 watts good thrust but lacks snappy throttle response. I was aiming for 1000Kv. The LRK was allot closer to the 1K mark coming in at 1040Kv. Little to fast for my target 11"SF prop but it swings a 10X4.7 with a vengeance. I plan on doing a side by side with the 2215's against stock wind. Just need the rainy windy day and a few hours.
I plan on posting my math before winding so if I get it wrong someone may point it out. When it's all together I'll test it and post the results.
Sounds like you have a good plan and it should be a good little motor. Since you now have a known Kv result from a LRK wind, I think you can use the Simple Turn Calculator to generate wind chart for the LRK winds. Turn Calculators 5 and 6 need to have the info from a dLRK wind to generate the other winds (including LRK).

The attached image is Turn Calculator 5 and gotten from entering the Kv from the specs and the turn count that I got as I stripped the original dLRK-Delta wind on the motor I did. You can see the 1450 Kv from the specs in cell G20.

I did an 18 turn LRK wind on the motor later and measured it's Kv as about 1170. The spreadsheet predicted 1154, the raw Kv's as I measure them will normally read a little bit higher, so it looked to me like the TC5 calculations are right on the money.

If your motor was 13 turns and dLRK-D maybe the predictions will work for you too.

I'm not really impressed with the quality of the machine windings. They might do better than the Chinese work force but any of us here would not brag about having done what I see there.

Jack

#6 jackerbes Jan 12, 2013 06:59 PM

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It occurred to me that you had told me the turn count on your motor so I ran TC5 again and changed the Kv to 1300 (current specs) and the turn count to 14. That should give you better predictions.

Cheers,

Jack

#7 Dr Kiwi Jan 16, 2013 10:30 PM

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Whoa! I just realized that I had tested this E-max 2210/30 motor back in '06... though it was said to be 1400Kv, my test stand measurements indicated that it was ~1695Kv!

#8 zeroback Jan 17, 2013 08:04 AM

The Emax's of that era apparently were hand wound, Jack's tear down of one was a gooped up mess. This Emax was machine wound, not much wire BUT the turn count was a perfect 14 turns on each arm. This one is sold as a 1300Kv and when tested was within 20 rpm. It did perform to the specs available at Heads Up RC. Although at that power level it was heating up and would be a considered a burst verses a constant power level. The unwinding revealed a phase that one of the three conductors was broken., with that wire in tacked the motor would have done better.

#9 zeroback Feb 06, 2013 10:09 AM

E-maxed out
 
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I'm thinking about mounting the motor with the wires hanging out so I can check the Kv terminated delta and star. Depending on which termination looks best for this motor. (I have a feeling it's going to be a Zero motor) I have a 3D or a Zero it will go into.

#10 zeroback Feb 06, 2013 12:13 PM

If I read the chart correctly this should be a 1382Kv terminated star

#11 zeroback Feb 06, 2013 12:22 PM

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First test) 1374Kv on 2S .8A Io .044 ohms. 6 RPM different than prediction, not bad.

#12 zeroback Feb 07, 2013 02:20 PM

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Installed some Boca ceramic hybrid bearings the no load current dropped to .7A 1373Kv 2S

#13 Fourdan Feb 10, 2013 02:16 PM

Hi Zeroback
No load current is dependent of lams temperature and so of running duration (no load)
Did you compared 0.7A against 0.8A in the same conditions ?
Louis

#14 zeroback Feb 11, 2013 08:40 AM

Once I had the bearings I hooked up the Emeter repeated the Io test ( run a few seconds on a half charged packed). Swapped out the bearings in about ten minutes and repeated the test w/ the new bearings. I have 3 2205's I'm running with these bearings (lube free) Emeter could detect no difference between stock bearings and ceramic. But in this case the OEM bearing's were bottom of the barrel and I installed the creme of the crop. I think that is why there is a detectable difference.

#15 zeroback Mar 02, 2013 04:10 PM

Impressive ?
 
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Or is it?


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