12N8P's ABCX4 STSD winding

[1BOHO]

Modisc,





AAAABBBBCCCC series delta which I see the end to end connection shown in your photo can be driven with a 3 phase esc but I think it is very different from ABCABCABCABC which is different with respect to the pitches and geometry of the commutation flux in the coils. These play a role in designing an "ideal" motor and control for a specific app. It should be very interesting to try these different wind in the same body on an dyne meter. Maybe the wind calculators "winding factor is not just blowing smoke" its described as calculating how much
of the wind in actually contributing to generating torque thats why a 1 would be better than ............" Wrong?"

"Winding factor
The winding factor for a specific winding expresses the ratio of flux linked by that winding compared to flux that would have been linked by a single-layer full-pitch non-skewed integer-slot winding with the same number of turns and one single slot per pole per phase. The torque of an electric motor is proportional to the fundamental winding factor.

The winding factors are often expressed for each space harmonic. If a winding factor is referred to without reference to a harmonic number, the fundamental winding factor is addressed. In the Emetor winding calculator, both the fundamental winding factor as well as the winding factor harmonics are calculated.

The winding factor kw can generally be expressed as the product of three factors, the pitch factor kp (sometimes also called coil-span or chording factor), the breath coefficient or distribution factor kd, and the skew factor ks:
kw=kp⋅kd⋅ks
The pitch factor kp reflects the fact that windings are often not fully pitched, i.e. the individual turns are reduced in order to decrease the length of the end-turns and do not cover a full pole-pitch (also called chorded).
Example:
2-pole 6-slot winding with coil span of 3 slot pitches (i.e. full pitch): kp=1.0
2-pole 6-slot winding with coil span of 2 slot pitches: kp=0.866
2-pole 6-slot winding with coil span of 1 slot pitch: kp=0.5
The distribution factor kd reflects the fact that the winding coils of each phase are distributed in a number of slots. Since the emf induced in different slots are not in phase, their phasor sum is less than their numerical sum.
Example:
2-pole 6-slot winding with 1 slot per pole per phase: kd=1.0
2-pole 12-slot winding with 2 slots per pole per phase: kd=0.966
2-pole 18-slot winding with 3 slots per pole per phase: kd=0.96
2-pole 24-slot winding with 4 slots per pole per phase: kd=0.958
2-pole winding with an infinite number of slots per pole per phase: kd=0.955
The skew factor ks reflects the fact that the winding is angularly twisted, which results in an angular spread and reduced emf.
Especially squirrel-cage induction motors have their rotor bars skewed by one slot-pitch in order to reduce the winding factor harmonics introduced by the slotting of the stator.

According to our definition of winding factor (The winding factor for a specific winding expresses the ratio of flux linked by that winding compared to flux that would have been linked by a single-layer full-pitch non-skewed integer-slot winding with the same number of turns and one single slot per pole per phase.), the winding factor of these single-layer full-pitch non-skewed integer-slot windings with one single slot per pole per phase must be 1.0!
Examples of winding layouts that have a winding factor of 1.0:
Single-layer 2-pole 6-slot integer-slot winding.
Single-layer 4-pole 12-slot integer-slot winding.
Single-layer 6-pole 18-slot integer-slot winding.
Single-layer 8-pole 24-slot integer-slot winding."

~https://www.emetor.com/glossary/winding-factor/~


1BOHO

[modisc731]

Originally Posted by 1BOHO

Modisc,





AAAABBBBCCCC series delta which I see the end to end connection shown in your photo can be driven with a 3 phase esc but I think it is very different from ABCABCABCABC which is different with respect to the pitches and geometry of the commutation flux in the coils. These play a role in designing an "ideal" motor and control for a specific app. It should be very interesting to try these different wind in the same body on an dyne meter. Maybe the wind calculators "winding factor is not just blowing smoke" its described as calculating how much
of the wind in actually contributing to generating torque thats why a 1 would be better than ............" Wrong?"

"Winding factor
The winding factor for a specific winding expresses the ratio of flux linked by that winding compared to flux that would have been linked by a single-layer full-pitch non-skewed integer-slot winding with the same number of turns and one single slot per pole per phase. The torque of an electric motor is proportional to the fundamental winding factor.

The winding factors are often expressed for each space harmonic. If a winding factor is referred to without reference to a harmonic number, the fundamental winding factor is addressed. In the Emetor winding calculator, both the fundamental winding factor as well as the winding factor harmonics are calculated.

The winding factor kw can generally be expressed as the product of three factors, the pitch factor kp (sometimes also called coil-span or chording factor), the breath coefficient or distribution factor kd, and the skew factor ks:
kw=kp⋅kd⋅ks
The pitch factor kp reflects the fact that windings are often not fully pitched, i.e. the individual turns are reduced in order to decrease the length of the end-turns and do not cover a full pole-pitch (also called chorded).
Example:
2-pole 6-slot winding with coil span of 3 slot pitches (i.e. full pitch): kp=1.0
2-pole 6-slot winding with coil span of 2 slot pitches: kp=0.866
2-pole 6-slot winding with coil span of 1 slot pitch: kp=0.5
The distribution factor kd reflects the fact that the winding coils of each phase are distributed in a number of slots. Since the emf induced in different slots are not in phase, their phasor sum is less than their numerical sum.
Example:
2-pole 6-slot winding with 1 slot per pole per phase: kd=1.0
2-pole 12-slot winding with 2 slots per pole per phase: kd=0.966
2-pole 18-slot winding with 3 slots per pole per phase: kd=0.96
2-pole 24-slot winding with 4 slots per pole per phase: kd=0.958
2-pole winding with an infinite number of slots per pole per phase: kd=0.955
The skew factor ks reflects the fact that the winding is angularly twisted, which results in an angular spread and reduced emf.
Especially squirrel-cage induction motors have their rotor bars skewed by one slot-pitch in order to reduce the winding factor harmonics introduced by the slotting of the stator.

According to our definition of winding factor (The winding factor for a specific winding expresses the ratio of flux linked by that winding compared to flux that would have been linked by a single-layer full-pitch non-skewed integer-slot winding with the same number of turns and one single slot per pole per phase.), the winding factor of these single-layer full-pitch non-skewed integer-slot windings with one single slot per pole per phase must be 1.0!
Examples of winding layouts that have a winding factor of 1.0:
Single-layer 2-pole 6-slot integer-slot winding.
Single-layer 4-pole 12-slot integer-slot winding.
Single-layer 6-pole 18-slot integer-slot winding.
Single-layer 8-pole 24-slot integer-slot winding."

~https://www.emetor.com/glossary/winding-factor/~


1BOHO

what you have quoted, i might have read it before, sounds familiar. very nicely stated!

[1BOHO]

Not at all trying to discredit you or your great winds but it just appears that the photo of the series connection of coils is this in a 12N8P:
AAAABBBBCCCC coil span 0?



Winding Factor .21


This is ABCABCABCABC which has a different coil span of 2?



Winding Factor .86

What I was suggesting is that maybe the servo motor wind designed to run with major gear reduction isnt
as concerned with torque output as someone building a motor for a 3d heli....
That doesnt at all take away from the value of knowing how different motors are wound for different applications.
We can always test the various winds real time for confirmation. This is my interpretation based on the different pitches of the wind. Maybe Im wrong but I want you to see that I really get this from somewhere not at all trying to hate on what you do.

It seems for instance for A that the cross should take place from 1 to 4 in 7 to 10 for STSD do u see?

In your photo your terminating leads arent from 1in12out, 4out5in,9in8out



This is why I was wondering did you have something different going on that made this a tru ABCABCABCABC?

I love the wind style and your winds just curious do we see the same things in the photos and why u think wind factor is negligible ? If Im wrong just show me .Im here to learn and teach when applicable.


1BOHO

[modisc731]

Originally Posted by 1BOHO

Not at all trying to discredit you or your great winds but it just appears that the photo of the series connection of coils is this in a 12N8P:
AAAABBBBCCCC coil span 0?



Winding Factor .21


This is ABCABCABCABC which has a different coil span of 2?



Winding Factor .86

What I was suggesting is that maybe the servo motor wind designed to run with major gear reduction isnt
as concerned with torque output as someone building a motor for a 3d heli....
That doesnt at all take away from the value of knowing how different motors are wound for different applications.
We can always test the various winds real time for confirmation. This is my interpretation based on the different pitches of the wind. Maybe Im wrong but I want you to see that I really get this from somewhere not at all trying to hate on what you do.

It seems for instance for A that the cross should take place from 1 to 4 in 7 to 10 for STSD do u see?

In your photo your terminating leads arent from 1in12out, 4out5in,9in8out



This is why I was wondering did you have something different going on that made this a tru ABCABCABCABC?

I love the wind style and your winds just curious do we see the same things in the photos and why u think wind factor is negligible ? If Im wrong just show me .Im here to learn and teach when applicable.


1BOHO

I see your point. I noticed the winding scheme picture i posted is different from what i actually did.
The reason is: the 12N8P STSD winding scheme is for a type of delta connection: arranging two wire ends which belongs to one ESC node, together.
what i actually did for now, is basically exactly the same as 3-wire technique: wind wire_A on tooth 1, 4, 7, 10 in sequence, then wire_B on 2, 5, 8, 11 in sequence, then wire_C...
what i mean by ABCX4, is ABCABCABCABC,. AAAABBBBCCCC is not a viable winding.

what i actually wind, and the winding scheme i posted, are actually the same, they are all ABCABCABCABC. the difference is how you connect them as ABCX4.

[1BOHO]

Thank you very much for you explanation. I will continue to watch your winds as I find them very interesting. Ill really look forward to testing them as well as some of the distributed winds. What would really be nice is to see if I can get a stator that is more suitable with 8 poles than 12N. I found a few Chinese suppliers that will supply you a stator to dimension.They usually have a minimum order though. Ultimately building my own bodies and having the stators supplied would be nice. I have a few older coreless inrunners. In your learning have you stumbled across the technique for laying them out and securing them to the can? I think I saw a patent on it sometime ago. As I remember in the diagrams the coils were layed out in almost a herringbone pattern really neat stuff.....




Your time a patience is always greatly appreciated.

1BOHO

[modisc731]

Originally Posted by 1BOHO

Thank you very much for you explanation. I will continue to watch your winds as I find them very interesting. Ill really look forward to testing them as well as some of the distributed winds. What would really be nice is to see if I can get a stator that is more suitable with 8 poles than 12N. I found a few Chinese suppliers that will supply you a stator to dimension.They usually have a minimum order though. Ultimately building my own bodies and having the stators supplied would be nice. I have a few older coreless inrunners. In your learning have you stumbled across the technique for laying them out and securing them to the can? I think I saw a patent on it sometime ago. As I remember in the diagrams the coils were layed out in almost a herringbone pattern really neat stuff.....




Your time a patience is always greatly appreciated.

1BOHO

I know "taobao" has a lot of stators, cheap. no minimum order. problem is you probably do not read Chinese....
http://s.taobao.com/search?q=hangmo+...ndexz_20141030

i have no experience in coreless inrunners.
good luck.

[1BOHO]

Ive done some reading and maybe coreless isnt the best thing for outrunners looking to produce gobs of torque. Im still in the learning curve on that......

Thank you for the link and maybe I can google translate thats what I did when you linked me to the forum where your winds reside. One of my logic instructors from college Tseng Woo, may also be able to help me with the language barrier.

Your time and patience is always greatly appreciated....
Hugh

[prototype3a]

AFAIK the thing coreless gets you is mad crazy efficiency. I believe the Kontronik Tangos achieved something like 95%.

[1BOHO]

That is a bench mark motor. Lehners run corless inrunners I think but NEU does not these are both two of the most efficient motors . The thought is the 2 pole coreless lehner would be better for rpm and the nue 4 pole 12N would make more torque. So I dont know how that factors into efficiency but it doesnt seem to suggest that the coreless is where the most torque would come from nor does it in the technical brief.

1BOHO