Feb 13, 2012, 07:56 AM who put that tree there Joined Jun 2010 809 Posts 16 mags and 12 teeth would like rewound to use 8x4gws on 2s lipo 26awg wire.. looking at chart i see 16 turns in delta term most suited to what i need is there a diagram for this termination thanks daren
 Feb 13, 2012, 08:29 AM Jack USA, ME, Ellsworth Joined May 2008 17,583 Posts Did the table say what wind it was? I think with 12 arms and 16 magnets your only choice for a wind is ABCABCABCABC. Have you ever seen these pages (ignore the German, click on EN where it is offered): Winding scheme table - http://www.powerditto.de/Kombinationstabelle.html Winding scheme calculator - http://www.powerditto.de/bewicklungsrechner.html Jack
 Feb 13, 2012, 10:14 AM who put that tree there Joined Jun 2010 809 Posts yeah same as link abcabcabcabc winding not sure what wires get soldered to where.i found 16 turns bit tricky after 4 or 5 goes i got it.. edit...found it wye term and delta term shall try both to see which suits better.. Last edited by dazza44; Feb 13, 2012 at 10:42 AM.
Feb 13, 2012, 10:56 AM
Jack
USA, ME, Ellsworth
Joined May 2008
17,583 Posts
Here is a good manual with images for both DLRK and ABC and both types of terminations:

The attached images were copied from there...

Jack

# Images

 Feb 13, 2012, 11:04 AM Jack USA, ME, Ellsworth Joined May 2008 17,583 Posts For the same number of turns and wire thickness: DELTA gives 1.73 higher power and amp draw than WYE DELTA Kv (RPM) = 1.73 higher than WYE Kv while the Kt (torque) = 1.73 lower If you go the other way, from Delta to Wye, the factor is 0.58 and it lowers the power and RPM.by 0.58 and raises the torque by 0.58. Jack .
 Feb 13, 2012, 02:27 PM Dave North USA, CA, San Jose Joined Apr 2004 5,254 Posts Murman: Are you absolutely positively sure there's no short from a wire to the stator? That's pretty much what it sounds like. Of course you're right to suspect the mags, but I assume you've checked polarity by now. Other than that, nothing obvious comes to mind. Nice looking work by the way ... Dave
Feb 13, 2012, 03:16 PM
Registered Aircraft Offender
Carmichael, CA
Joined Feb 2007
3,545 Posts
Quote:
 Originally Posted by Murman ...Could the mags be the problem? I guess it could be possible that they glued a magnet or two in backwards? What else can I check?
I highly doubt it would even start with a flipped magnet. It is possible for a misaligned magnet to cause inefficiencies and add to heat. From your photo, as expected the factory didn't do a super clean job on your rotor, but I don't see anything that stands out from the norm.

Heat:
I avoid mentioning the fact that the term 'easy wind' implies 'mediocre efficiency'. 10t-24awg is still an improvement over stock, but it won't be nearly as capable as a 10t-23awg. That said, 24awg is going to get very hot on the bench if you run it much longer than 5-10seconds. This isn't a problem as long as you keep bench testing short, and ensure the motor gets lots of cooling while in flight. Though you may want to check amps in case you have to prop down a bit.

Stuttering:
Is it losing sync (prop suddenly stops and the motor screeches), or is it more like random hiccups in RPM? Does it seem to happen more with gradual increases in throttle... less when you drop the hammer? Does it appear to happen at the same RPM every time? If everything checks out, it's usually a esc issue. OTOH, aren't you using a plush? Those are pretty bullet proof as far as high rpm sync goes.

Kev
Last edited by Truglodite; Feb 13, 2012 at 03:23 PM.
Feb 14, 2012, 07:34 AM
USA, NC, Huntersville
Joined Jul 2008
4,255 Posts
Dave and Kev, to best answer your questions, I decided to make a short video of what the motor is doing. I was slowly increasing the throttle during the 3 motor runs. Notice how it seems to start up correctly, but then hiccup. If you watch closely, you will see some smoke during the second test. I checked again before the test to make sure there wasn't a short from the leads to the stator. And I also checked to make sure none of the phases were shorted together. I ran this test with a Plush 18, and previously with an esc I got from Don's Rc (which also happens to work with the same programming card as the Plush's). The motor reacted the same way with both esc's.

 Turnigy 2730-3000 issue (0 min 56 sec)

Edit....Ok, now I feel a bit embarrassed. After posting this video, I started wondering if mounting a prop and testing the motor with a load would make a difference. It did. The motor now spools up nicely (even after letting out some smoke) and produces 14.5oz of thrust at 256 watts (peak) and draws 24a with a freshly charged NanoTech 850mAh 3s battery and 4.75x4.75 prop. I'm now debating whether I should go ahead and rewind it using 23awg.
Last edited by Murman; Feb 14, 2012 at 08:54 AM.
 Feb 14, 2012, 11:01 AM Registered Aircraft Offender Carmichael, CA Joined Feb 2007 3,545 Posts Heck yeah, go for it! Just keep everything as tight as you can. The last turn is a squeeze, but no special tricks are needed for 10t-23awg. BTW, weird what happened earlier... must have been hitting the esc switching limit with no load. I mentioned before... my no load testing stops above 3000kv 3s. Kev
 Feb 14, 2012, 01:12 PM Dave North USA, CA, San Jose Joined Apr 2004 5,254 Posts Interesting. I've done very short no-loads on a couple of high Kv motors without any problems, but when I say very short ... woo! Dave
 Feb 14, 2012, 04:44 PM Someone get me a ladder! USA, NC, Huntersville Joined Jul 2008 4,255 Posts You guys have, once again, taught me something. I didn't know I had to test a high kv motor with a load. Thanks for sharing your knowledge with the rest of us. Latest blog entry: My new favorite plane...the SlowBoat
 Feb 14, 2012, 05:05 PM TeachSeventh Houston Joined Dec 2008 133 Posts check your timing on your ESC or maybe try a different flavor of ESC,
Feb 18, 2012, 12:39 PM
homo ludens modellisticus
Netherlands, GE, Nijmegen
Joined Feb 2001
11,447 Posts
Quote:
 Originally Posted by jackerbes For the same number of turns and wire thickness: DELTA gives 1.73 higher power and amp draw than WYE. ...
Kv goes up with factor √3 = 1,73. But Jack, power for propellor goes up cubed with rpm, therefore power wants to go up cubed with Kv, by a factor (√3)³ = 3√3 = 5,2.

Same for motorcurrent, wants to go up cubed(³) with Kv, ideal components, worst case (hence the wants to). Of course this does not mean that the motor can handle that current.

Motorcurrent wants to go up squared (²) with voltage, again worst case.

Prettig weekend Ron
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Last edited by Ron van Sommeren; Feb 19, 2012 at 03:06 PM.
Feb 20, 2012, 12:13 PM
USA, NC, Huntersville
Joined Jul 2008
4,255 Posts
I twisted up a 16mag 12t 23awg wye motor this morning to see if I could do it. Actually, I started out trying to do a 21t 26awg, but gave up after losing count a couple of times. I've only been able to do it once and it's my favorite motor. Anyway, back to the 12t, it was a success. I figure what I lost in efficiency by not doing the 21t, I maybe gained by using 23awg on the 12t.