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Old Apr 13, 2012, 03:28 PM
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About 12N14P dLRK DDDD connection

I just finished a winding on a 4120 12N stator, each tooth winding with a single wire. willing to connect as DDDD. I tried twice, but both time, the motor can run but no load current is high. and great friction is felt if i turn the rotor by hand. Obviously, my termination is not right.

Anyone have any idea about a dLRK DDDD connection scheme?

I found dLRK DD connection scheme and 12N8P ABCX4 YYYY connection scheme (http://www.powerditto.de/12N8P4225YYYY.html), but i still cannot figure out about dLRK DDDD.

Thanks
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Old Apr 14, 2012, 11:38 AM
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the stator is winded following "single teeth single direction winding" http://www.rcgroups.com/forums/showthread.php?t=1614226

So i have 24 wire ends, labeled as 1_in, 1_out, 2_in, 2_out....12_in and 12_out.
basically, i can produce any type of winding by connecting these 24 ends properly.

This motor is winded with single strand of 0.64mm wire, 66 turns in each slot (33 on each teeth).
I previously winded a same motor (4120 same stator, same magnets ), using 4 strands of 0.64mm wire, 16 turns, dLRK, delta connection. Kv around 510, no-load current @20V is 1.48A.
For the motor winded with single strand of 0.64mm wire, i manage to input 2 more strands in each slot (66 vs 64). By connecting the 24 ends to dLRK DDDD, in theory, this will produce approximately the same Kv as my previous motor.

Then comes the interesting part: will there be any obvious difference between the two motor.

What i have tried for now, is trying to connect the 24 ends to 2 sets of separate LRK windings: wires on teeth 1, 3, 5, 7, 9, 11 are connected as LRK DD; and wires on teeth 2, 4, 6, 8, 10,12 are also connected as a separate set of LRK DD.

both groups works well separately, producing approximately the same Kv and no load current at the same voltage. But, no matter how i connect these "6 out put ends" of the 2 sets of LRK DD, i always feel the "strong resistance" when i turn the bell by hand, meaning it is not right.

I am trying this, cause LRK has a better winding factor than dLRK. If 2 separately sets of LRK winding on the same 12N stator can work when they are connected parallel as one, then this new double LRK DD for 12N14P or 12N10P will have a better winding factor than dLRK, while maintaining the benefits of winding all the teeth. Sadly, initial attempt failed.
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Old Apr 14, 2012, 03:44 PM
mty
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I guess the problem is that now you have two windings geometrically rotated 30 degree from each other and you can't simply connect them in parallel. How about connecting the two windings to two ESCs?
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Old Apr 14, 2012, 03:57 PM
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Originally Posted by mty View Post
I guess the problem is that now you have two windings geometrically rotated 30 degree from each other and you can't simply connect them in parallel. How about connecting the two windings to two ESCs?
You are right. connecting to two ESC is not my goal...my actually goad is to make this motor the highest Kv possible, and that is why i wanna use dLRK DDDD.
I guess, if the motor can be successfully winded to dlrk DDDD, it may have the same kv as 4 strands, 16 turns, dLRK delta. But it will be interesting to see whether there will be any difference between dlrk delta and dlrk DDDD having the same kv.

another goal is to connect these 24 ends as double LRK DD, which will also have the same Kv. Since lrk have a better winding factor than dLRK windings, i was hopping that the double LRK DD will perform better than dLRK. However, i attempt on double LRK DD fails....
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Old Apr 14, 2012, 04:02 PM
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I have not tried on double LRK yet. donno whether this will work or simply impossible. It could be amazing if double LRK can work, for a 12N10P or 12N 14P motor. this will combine both benefits of LRK's high winding factor, and dLRK's better arrangements of the coils.

actually, dLRK can be viewed as 2 LRK connected in series, not in parallel.
normal dLRK: AabBCcaABbcC
can be viewed as A-b-C-a-B-c- , and -a-B-c-A-b-C, both are LRK. connected in series, to be a dLRK
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Old Apr 18, 2012, 01:06 AM
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I don't think there can be dLRK DDDD or YYYY.

What makes an dLRK magnet circuit is the "V-shaped" flux path on each pair of stator arm, when energize. If my description is even correct. As dLRK is a derivative of LRK which has a "W-shaped" flux path.

If you parallel any of the "phase's distributed wind", Aa, Bb, Cc, the current will circulate in that phases, "un-energized". What you then get is an effect similar to that of induction motor. Or an "eddy current-like" resistance as the magnet passes over the "hammerhead".

Quote:
both groups works well separately, producing approximately the same Kv and no load current at the same voltage. But, no matter how i connect these "6 out put ends" of the 2 sets of LRK DD, i always feel the "strong resistance" when i turn the bell by hand, meaning it is not right.
This could be the reason "PowerCroco" doesn't allow parallel connecting the "phase's distributed wind".
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Old Apr 18, 2012, 09:38 AM
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Here's the page.


Name: Parallel_wind.JPG
Views: 121
Size: 135.6 KB
Description:
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Old Apr 19, 2012, 07:46 AM
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Originally Posted by BoomStriker View Post
I don't think there can be dLRK DDDD or YYYY.

What makes an dLRK magnet circuit is the "V-shaped" flux path on each pair of stator arm, when energize. If my description is even correct. As dLRK is a derivative of LRK which has a "W-shaped" flux path.

If you parallel any of the "phase's distributed wind", Aa, Bb, Cc, the current will circulate in that phases, "un-energized". What you then get is an effect similar to that of induction motor. Or an "eddy current-like" resistance as the magnet passes over the "hammerhead".



This could be the reason "PowerCroco" doesn't allow parallel connecting the "phase's distributed wind".
Thanks a lot, B.S., for your explanation.
I have basically tried every type of connection that I can think of, to get a DDDD, but all the attempts ended up with a "sticky" feeling when turning the rotor by hand, indicating that the current is not flowing right. I have no the knowledge of the theories behind these windings, so the only thing I can do it to try it out.

The best thing I get from all these failed attempts, is that I made two separate half parallel LRK windings on the 12N stator, each taking 6 of the teeth. Both works well separately. But the two LRK can not be connected parallelly. As I stated before, I found that the distributed LRK can actually be seen as Two LRK winding connected in series.

This may give a hint to those who wanna make a electric motor transformer, which is normally composed of two separate motors whith their shaft connected: driving one motor with electricity, get a different voltage out from the outlet wires of the other motor. Why not use a single stator, winded with two separate LRK, which has a very high winding factor? With the number of turns being different for the two separate LRK, it makes a perfect high efficiency transformor, I guess.
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Old Apr 27, 2012, 04:17 AM
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Hi,
Better you wind this two LRK motors with the same number of winds and Drive each with a seperate esc. If you do so you will have a real 6 phase system.Most powerfull motor you can get in the modelbuilder world.
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Old Apr 27, 2012, 09:15 AM
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Originally Posted by Christian Lucas View Post
Hi,
Better you wind this two LRK motors with the same number of winds and Drive each with a seperate esc. If you do so you will have a real 6 phase system.Most powerfull motor you can get in the modelbuilder world.
Thanks for the hint.

Initially, i am expecting to wind the 12N14P motor as parallel dLRK DDDD. So, all the 12 teeth are winded with a single 0.64mm wire, with the same number of turns (33 turns). So i have 66 turns in each slot, and 24 wires to be connected.

As stated above, i have tried everything i can think of, but cannot get the right dLRK parallel dddd if it is possible. Is it even possible to connect all the 24 ends as dLRK parallel DDDD?

Anyway, then i wired the 24 ends as 2 separate groups of LRK DD, as stated before. Both works fine separately. But i have not try to use two ESC to drive the 2 groups of LRK on the same motor yet. I have a few questions:
1, do i need to use 2 identical ESC to drive the 2 groups of ESC on the same motor, to make the motor run?
2, In order to adjust the speed of the motor, do i need to connect both esc to a single servo tester?
3, what do you mean by it will be most powerful? I mean, what advantages do a 6-phase motor have over a 3-phase motor?


Thanks

this is how i connect the 12 ends as LRK DD
http://www.rcgroups.com/forums/showthread.php?t=1614226
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Last edited by modisc; Apr 27, 2012 at 09:22 AM.
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Old Apr 27, 2012, 03:25 PM
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Hi,
If you want to do so ,you have to design an new stator with statortoth with different angel .The problem is that the corosponding teeth with the A and a Winding on have to see the magnet at he same time .The electromagnetic induced volts must be synchron rising and lowering n the corosponding phase and tooth.If they differ you will get short circuit current that will break the rotor .This you can feel when you turn the rotor by hand .In dlrk the both teeth are wind in series wich result in a wave form with a flat peek at the top and thats the reason for the higher kv with this wind.
Magnetical the 12 slot and 10 / 14 Magnet system is a 6 phase system with the LRK and the dLRK winding sytem. The LRK winding uses a 3 phase controller that swing with the double frequenz like the 6 phase.If you want 6 phase you need a 6 phase controller but also two 3 phase controller will do the job.Moore phase will rise the performance. We have build motors called modularer magetmotor that has for each stator tooth a 2 phase controller with it you have the freedom of how many magnets you want to install. You can now install 62 magnets and 61 Statortooth .Only the magnets have to difide with 2 as you need allway north and south but the numbr of statorteeth can one moore or less than the magnets or any other count .That´s the reason in the sub as the sub moor can run with only one 2 phase controller and all other are dead.You see each tooth workes for it self .The German Sub with fuelcell drive has such motor from Siemens , http://www.industry.siemens.com/data...ermasyn-en.pdf . You are on a good way ,keep on thinking.
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Old Apr 27, 2012, 09:31 PM
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Quote:
Originally Posted by Christian Lucas View Post
Hi,
If you want to do so ,you have to design an new stator with statortoth with different angel .The problem is that the corosponding teeth with the A and a Winding on have to see the magnet at he same time .The electromagnetic induced volts must be synchron rising and lowering n the corosponding phase and tooth.If they differ you will get short circuit current that will break the rotor .This you can feel when you turn the rotor by hand .In dlrk the both teeth are wind in series wich result in a wave form with a flat peek at the top and thats the reason for the higher kv with this wind.
Magnetical the 12 slot and 10 / 14 Magnet system is a 6 phase system with the LRK and the dLRK winding sytem. The LRK winding uses a 3 phase controller that swing with the double frequenz like the 6 phase.If you want 6 phase you need a 6 phase controller but also two 3 phase controller will do the job.Moore phase will rise the performance. We have build motors called modularer magetmotor that has for each stator tooth a 2 phase controller with it you have the freedom of how many magnets you want to install. You can now install 62 magnets and 61 Statortooth .Only the magnets have to difide with 2 as you need allway north and south but the numbr of statorteeth can one moore or less than the magnets or any other count .That´s the reason in the sub as the sub moor can run with only one 2 phase controller and all other are dead.You see each tooth workes for it self .The German Sub with fuelcell drive has such motor from Siemens , http://www.industry.siemens.com/data...ermasyn-en.pdf . You are on a good way ,keep on thinking.
Your answer is very inspiring, and confirms some of my guess. why the number of the tooth has to be a multiple of 3, the reason is we are using a 3-phase controller. If every single tooth has its own phase, then there will be no such limit, as long as the number of magnets is a multiple of 2, simple because we only have "south" and "north".
I am still not very sure but when you explain why 6 phase is better than 3 phase, i guess you mean 2 peaks joined together working as one "flat peak" (3phase)is not as good as 2 peaks working separately(6 peak).

I have specific interest in brushless motor and motor design, not in "flying a plane or heli" actually. It is very beneficial to hear from someone who knows what really is going on in the "spinning bell". Thanks.
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Old Aug 18, 2014, 07:56 AM
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Antony (France)
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Hi
Past week-end, a friend of mine and myself we tried to wind a Scorpion 7050 kit
(that is 12N 10P)
We tried single strand (1mm dia. copper)
We wound 12 coils independently (24 endings) all same turns (20 /tooth)

Then we tried dLRK with a connection YYYY
The Kv seems correct, but Io no load is very important and abnormal (IMO)

That seems to confirm Modisc's experiment
All parallel dLRK seems to have "bad functionning"
We have to continue the rewinding study (half parallel test YY .. Kv twice rpm/V)

I have also to think again-about the theoretical approach and the simulation with my own software.

Louis
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Old Oct 04, 2014, 08:41 PM
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Yea. YYYY or DDDD is probably only valid on 12n8p or 16p ABC WINDIngs.
DLRK 12n10p or 14p can only do YY or DD.

I recently would like to get a 7050kit myself. Do you mind sharing me with the exact dimension of the lamination? So that I can figure out what sized wire to use. Thanks. Was thinking about using 12AWG though.

Xiaochen


Quote:
Originally Posted by Fourdan View Post
Hi
Past week-end, a friend of mine and myself we tried to wind a Scorpion 7050 kit
(that is 12N 10P)
We tried single strand (1mm dia. copper)
We wound 12 coils independently (24 endings) all same turns (20 /tooth)

Then we tried dLRK with a connection YYYY
The Kv seems correct, but Io no load is very important and abnormal (IMO)

That seems to confirm Modisc's experiment
All parallel dLRK seems to have "bad functionning"
We have to continue the rewinding study (half parallel test YY .. Kv twice rpm/V)

I have also to think again-about the theoretical approach and the simulation with my own software.

Louis
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Old Oct 05, 2014, 03:27 AM
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Antony (France)
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Hi Xiaochen
Here are some infos regarding Scorpion HK7050 kit
Stator 70.02mm (diam) x 50mm, laminations 0.2mm
Stator weight 570 g (without any copper)
Rotor weight 647 g (with shaft, with magnets)
Louis
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