The flame/heat gets in between the winding nicely. I may have been lucky with the epoxy used on the spaghetti, but once heated the windings came off easily. No gloves needed, just a rag for the odd bit of hot copper

Next step is to borrow your great trick of doing a fast temporary motor-wind, to test windings for a new KV. Just to check, using this technique your final permanent-wind KV was exactly the same as your temporary-wind KV?

Exactly the same, since you need to check kV unloaded even a thin wire will suffice as current will be very low.
I almost forgot this is not a discussion thread so please contact me in one of my threads or blog if you need.
Ron, please feel free to delete posts that you don’t find relevant to this thread.

You are discussing a method, not a build
But I suggest Argo start a dedicated thread for his build to keep this FAQ lean and mean. More viewers/input as well.

The calculation for the 'quick and dirty' method is explained in the opening post under
16. Calculating number of winds for desired new Kv.

Wees voorzichtig, Ron

Here is a 'tool' I put together when I was looking to twist multiple parallel strands together.

Old news to use a drill, the 'twist' (pun alert ) is to tape a magnet to the chuck and your phone to the top. Use an app that senses magnetic fields (the app in the photo is: iOS "Turns Counter". With the right settings, every time the magnet goes past the phone the count increments by one.

There are also some great 'Event Counter' apps for keeping track of the number of turns when winding onto the hammerhead.

Removing a shaft using a vise, washers and nuts, in pictures - RCG

Click to enlarge


Still cannot edit (copy to) opening post

Vriendelijke groeten Ron

Great tip Ron. I've done it a few times using a small PVC pipe instead.

I think that maybe your problem was the size of the image. It was 3333 pixels high, I used irfanview to resize it to 500 high and that is attached here and you should be able to copy and save that. You might want to choose a more meaningful name for it...

Jack

Picture size is not the problem here Jack, it's just a small (RCG) picture that links to the larger (RCG) picture.
It's a frustrating problem, since more than a year, RCG knows the problem, knows how to circumvent, but alas ... policy.
My problem report and RCGs reaction:
new type of sorry you have been blocked error message

Vriendelijke groeten, en wees voorzichtig, Ron

I just had an odd thought on this problem Ron. Can you quote your first post and edit the quote?
If so, maybe you could start a new thread with that quote and request it be be stickied and merged with this one if all else fails.

Originally Posted by Ron van Sommeren

Picture size is not the problem here Jack, it's just a small (RCG) picture that links to the larger (RCG) picture.
It's a frustrating problem, since more than a year, RCG knows the problem, knows how to circumvent, but alas ... policy.
My problem report and RCGs reaction:
new type of sorry you have been blocked error message

Vriendelijke groeten, en wees voorzichtig, Ron

Ron, have you ever done an inrunner? A friend of mine has and has a thread on it in a different forum.

His thread has lots of good things in it and if interested I can link it somewhere you may feel it is most appropriate... or not?

TIA.

Inrunners, outrunners, who cares, as long as it's diy

Prettig weekend Ron

Great thread btw. Thank you!

In runner rewinding.
https://forums.offshoreelectrics.com...ass&highlight=

https://forums.offshoreelectrics.com...p-report/page3

Hi all. My name is Ron Frazier. I'm a newbie to the forum and a newbie to BLDC design. I've been doing lots of research on these BLDC motors, including reading much of this thread. I've learned enough to be dangerous and I thought I'd share. I'm very much a newbie at this, and certainly don't know enough to really explain things. But maybe I can at least explain what I'm posting. If some of you know more than me, please share and be gentle if I mess up.

I am trying to identify the basic structure of a BLDC that I may build if I can get, and afford, the parts. Two of the most critical attributes are the number of slots in the stator (stationary part with coils) and the number of magnets, or poles in the rotor.

I found this article that describes the trade offs involved.

https://things-in-motion.blogspot.co...-and-slot.html

Based on this, I've concluded there are three factors I want to initially keep in mind.

The ratio of slots to poles or Q, accounting for a 3 phase motor, is one. Poles always increase in increments of 2. For a 3 phase motor, slots always increase in increments of 3.

As far as I can tell, the formula for this is Q=Slots/Poles/3. This relates to how much surface area of the magnets is adjacent to how much surface area of the slots' teeth. He says to keep Q >= .25.

So, as an example, if there are 12 slots and 16 poles, designated 12N16P, then
Q=12/16/3=.25 If the poles increase any higher, then Q drops below .25.

He has a chart for this in the article.

https://1.bp.blogspot.com/-rwnA057Rf...00/q-vales.jpg

So, my first criteria is that Q >= .25.

The second criteria is the number of cogging steps per turn. As the magnets rotate past the iron teeth of the stator, the magnets attract to the iron. This resists rotation. This creates vibration. If you're manually turning the motor as a generator, each cogging point is where it will resist the motion.

I have arbitrarily decided that I want 90 or more cogging steps per turn, or 1 every 4 degrees. According to the article, the higher the number the better, and the smoother the rotation.

The third criteria is the winding factor. According to the article, the winding factor is a number between 0 and 1 which represents the fraction of the armature current which is used to produce torque.

You want this as high as possible. As a practical matter, it stays under 1. I've decided I want the winding factor to be above .9.

He has a chart for this. This chart shows the winding factor for slot and pole combinations which also meet the Q >= .25 criteria.

https://1.bp.blogspot.com/-PquAnXA2q...han%2B0.25.jpg

So, I wanted to determine what slot and pole combinations would meet these three criteria.

I used this motor calculator.

https://www.emetor.com/windings/

I'm looking for green items on this chart. Other colors include Integer-slot winding, Fractional-slot winding, and Unbalanced winding. Green means Concentrated winding, which is what I want. This means I'm winding the wire around each slot's tooth.

The controls for this calculator identify the middle row and column. But you can read lower numbers than those.

Slots are listed on the left and poles are listed on the top.

I set the controls so I can see the row for 3 slots. The maximum number of poles to keep Q>=.25 is 4. Neither 3N2P nor 3N4P have a winding factor above .9, so I pass them by.

I look at the row for 6 slots. The maximum number of poles to keep Q>=.25 is 8. Neither 6N4P nor 6N8P have a winding factor above .9, so I pass them by.

I look at the row for 9 slots. The maximum number of poles to keep Q>=.25 is 12. Both 9N8P and 9N10P have a winding factor above .9.

Now I go to this calculator and plug in these numbers.

http://www.bavaria-direct.co.za/scheme/calculator/

For 9N8P, I get 72 cogging steps and .945 winding factor.

I reject that because 72 cogging steps is too low.

For 9N10P, I get 90 cogging steps and .945 winding factor. I add this to a chart of possible configurations that meet the Q>=.25, 90+ cogging steps, and .9+ winding factor.

Using these procedures, I check every possible combination.

Here are all the combinations which meet these criteria from 3-33 slots.

9N10P
15N14,16P
18N14,16,20,22P
21N20,22P
24N20,22,26,28P
27N22,24,26,28,30,32P
30N26,28,32,34P
33N26,28,32,34,38,40P

So, as far as I can tell, motors of all these configurations should run with reasonable torque due to Q, reasonable efficiency due to wiring factor, and reasonable vibration due to cogging steps.

Now, I just have to figure out which one to build and how to get parts.

Hope this helps anyone who's interested in the topic.

RonF

Finding the individual parts for a typical brushless motor like we use in RC is not easy. A good way to get started on learning more would be to rewind a motor you already have in hand. That would give you a stator, base plate/bearing tube, magnet housing with magnets, and the bearings and other bits and pieces.

Then you could experiment with and learn from the different winding methods and winding termination methods that could be tried on that particular combination of stator arms magnets. There can be significant differences in the results on the different choices. And if you work more neatly than the workers at an average Chinese motor maker's plant, you can use the same wind they did and you'll almost always get a better motor

The first image is a factory wound 12 arm 14 magnet motor with a dLRK Delta wind and to the left of it the motor has been rewound to 2PdLRK-Y (half parallel dLRK Wye terminated). This thread explains how that rewind was accomplished:

hexTronik DT750 Motor 2PdLRK Rewind for Multicopter - https://www.rcgroups.com/forums/showthread.php?1892195

Here are a couple of the posts or threads that compare the benefits of rewinding and changing winds from one type to another:

LRK Wind on DAT-750 - It's a good one! - https://www.rcgroups.com/forums/show...postcount=1409

Outrunner Disassembly and Stripping - Gimbal Motor Rewind - https://www.rcgroups.com/forums/showthread.php?1823636

As you browse threads here you'll soon spot the forum users that have the most knowledge and interest in a topic and if you click on their user name you can look at their blog page. And from there you can see their threads, posts, and attachments and there will be more info to be learned from that.

As an example, my blog page is here: https://www.rcgroups.com/forums/member.php?u=211021

Here is a web page that was a great help to me, I think maybe the second image is from there:

https://www.flybrushless.com/

I don't claim to be the smartest or best at any particular aspect of this hobby but I've been posting here since 2008 and it has been wonderful entertainment for me in my retirement years.

Good luck with your pursuits here and don't overlook the value it can be to others of when share what you learn!

Jack