Need some motor pole clarification

[Motopreserve]

What's up folks. Hoping I can get some clarification on something I've been researching for the past 24 hours, and frankly, I'm starting to lose my mind...

I have a set of SunnySky 3508-20 580kv motors. They are listed on the product page as "28 pole." By all accounts, it seems these would be considered "high pole count" motors, although I have yet to find a definitive answer to when pole counts switche from being considered low (or normal) to high (is 12 pole low? Is 18 pole low or high, and what about 20+???). When I was first planning my build, I also had a fair amount of frustration finding info about ESCs (and the firmware) that would be appropriate for high pole count motors, with conflicting info/data regarding SimonK, and various opinions about other ESCs that have worked (or not) on these specific SS motors. I was doing all this research based on the assumption that my motor was high pole count.

I settled on HobbyWing Platinum Pro Opto for the build, mainly because there had been great feedback from many of you here that are running high pole count motors. In an effort to fine tune the advance timing, I finally took a look at the motor itself (should have done this first thing, I know!), only to find that based on my cursory count (counting the coils and counting the magnets on the outer bell), the motor looks to be more like a 12N14P motor. Eegads! Have I been barking up the wrong tree this whole time???? Or am I counting wrong???

I found a photo online that showed a disassembled motor (not SS) that has twice the number of stator (inner) magnets as the number of coils/copper wire windings. Lending to the confusion is that a company like KDE lists specs for both stator AND magnet poles, and they definitely do not have twice the number of inner magnets to coils...

So I am looking for clarification on a couple things:

1. What is considered high pole count? What is considered low (or normal)?
2. When people talk about pole count, are they talking about stator poles or magnet poles?
3. When trying to count poles, are the number of coils/windings the stator poles? And would this number represent the total bumber of stator magents? Or does design vary by manufacturer?
4. Without taking the motor apart, if I cont the magnets i can see through the top - is this the number of poles? Or are there magnets hidden in there that would make the pole count higher than I can see???

Thanks for any insight you can provide. My brain is swimming in molasses right about now...

 

[Scott Drysdale]

I am going from memory so for what it is worth. The pole count in based on the number of magnets only. Coil count will always be less. Pole count is relative such that high versus low is not very definitive. But I consider 22 pole motors a high pole count type. The trend now is towards larger radius motors that are shorter for improved efficiency, aka, pancake style motors. I avoid purchasing any ESCs loaded with SimonK firmware at this time. Best bet is to use OPT ESCs that are specifically sold for MRs and do not have SimonK loaded. Many of these having Atmel processors that can be reconfigured in the future with SimonK once SimonK has this issue resolved.....

 

[Motopreserve]

Thanks for the response scott.

I avoided the SimonK flashed ESCs - but that was because I was assuming that my motors were high pole. But if they are lower (14?) as my count seems to suggest, I could have been a little less worried about the particular ESC. Ultimately, I'm more concerned with knowing where to head with my advance timing (up or down) - right now I'm up at 20 degrees which may be inappropriate for a 14 pole motor, but not a 28 pole.

At this point I'm waiting to hear back from both buddyrc and SunnySky to see of I can figure out whether I'm A) counting these motor poles incorrectly or B) due to factory mishap the body/bell is incorrect for the actual innards that I have.

 

[Motopreserve]

UPDATE:

I heard back from BuddyRC about the SS V3508-20 580kv motors. They confirmed that these are in fact 14 pole motors, not the advertised/listed 28 pole.

While in theory, I'm fine with the lower pole count, I'm not fine with having spent the time and money to find ESCs that would appropriate for a motor spec that I didn't actually receive, and most importantly the risk I may have exposed the Hex to by setting the advance timing very high for a high pole count.

Shame on me for not checking the count sooner, guilty of believing what I read

Water under the bridge...

 

[cootertwo]

But we all get to learn! Thank you.

 

[Motopreserve]

But we all get to learn! Thank you.

Thats what I'm hoping for, others to learn from my mistakes.

Honestly, I really think there needs to be a push by consumers to insist that consistent info/data be provided on these products. And a bonus would be correct data!!!

Companies like KDE and T-Motors provide a wealth of information. I know sunnysky is a much cheaper alternative, but I don't feel they are so cheap that we should not be able to expect basic data on the products we are buying.