First time rewind project

[DannyvG]

I did my first rewinding project yesterday.
the victim motor was a old gaui 500 size motor a friend had laying around. I didnt measure original kv, Rm, no load current and such, should do that with the other motors I intend to rewind.
Based on this thread https://www.helifreak.com/showpost.p...06&postcount=3 I chose to do the rewind in 4+4 YY with 0.9mm wire.
Will have to make a motor stand with eagle tree and such to measure kv but the motor has run already shortly and it seemed to run smoothly, at least without flames and smoke

Now after this first attempt I hope to get some tips or pointers based on the pictures below.
One thing I am wondering about is where do you solder the esc wires, do you do that as close to the motor as possible or just twist up the wires and only solder the end?
Do you need to isolate all single strands or wont it matter that you twist them up against each other?

Also when looking at this picture from http://www.powerditto.de/schemamodus12N_YY2.html

what way is preferred? I now used the green method but I noticed that the outer wire will easily slip out of the slot when finishing up the motor.
The disadvantage of the blue/purple way is that I cant put in the wire trough the slot but have to feed the wire through form the top to the bottom.

And what is the best method to remove the enamel from the wires ends? I now used a grinding stone on my dremel but that also removed some copper. Perhaps a wire brush on a dremel works? Or just scrape it of with a knife?

Some pictures of my first rewinding.

[_Dekker]

Hey djamgils,

Welcome to the winder's club!
Nice job done, a working motor gives great satisfaction, doesn't it?
What is the stator diameter and length of this motor?
Most of your questions I already answered through email. About the enamel removal: just scrape it off with a scalpel. make sure it is sharp, that helps a lot. For testing a dremel is OK but for performance you want the whole copper section intact.
I do not twist the wires coming from the motor anymore: you want to minimize wire length as best as possible and also with thick wires you might run into space problems were the wires exit the motor.

Bert

[DannyvG]

Thanks for the tips. It gives a lot of satisfaction indeed, I was pretty surprised nothing went up in smoke This motor was just for practicing, didnt intend to fly it in a helicopter. Hopefully I can put a prop on it to load it a bit.

Next motor will be a bit taller version of this motor and I hope to test it in a trex500 or protos. I will try the blue method next time and probably also use some insulation paper to be safe. Or isnt that needed when the stator is coated properly?
I did test this motor with 1000V and it didnt have any shorts, despite the fact I damaged the coating on some places but that wasnt directly on any wire.

I will check the dimensions of the stator tonight.

[_Dekker]

Originally Posted by djamgils

I will try the blue method next time and probably also use some insulation paper to be safe. Or isnt that needed when the stator is coated properly?
I did test this motor with 1000V and it didnt have any shorts, despite the fact I damaged the coating on some places but that wasnt directly on any wire.

You only need the paper if the stator does not have a nice colored epoxy coating, so in your case no need for paper.
The coated stators are most sensitive to damage on the corners where you bend the wire, so you have to be careful there.

[ZuvieleTeile]

@ djamgils,
nicely done.

in regards to the winding methods.
The "blue" method has two advantages.
- It gives you the shortest wire length
- The outer winding stays better in place and does not tend to slip off the stator.

Sure, a little bit more work in threading the wire, but pays off in the end. . .

[DannyvG]

The stator diameter was 35mm, stator height 19mm.

I did a no load testrun on 3S yesterday.
I found a kv of 1760rpm/volt and a no load current of 6.5A @11V. That no load current seems a bit high? I removed the stator to check if I soldered everything correctly but cant find any problems.

[DannyvG]

I did the second gaui motor yesterday but I have some problems with it.
When testing the 2 partial motors I get 1440kv and 6A no load for 1 side and 1600kv (with changing rpm) and 20A no load current on the other side.
So probably there is a short between some of the windings?
Any tips to find out which one, my voltmeter only measures down to 300mOhm so no use with that one. Are there more accurate ways to check the resistance of the separate coils?

[KingofQueens]

You need a megger.
Most of those can measure up to 2000 Ohm and you are able to shoot 1000 Volts through the windings and test this way for shortages.
For Europe maybe you have a look here:
http://www.ebay.de/sch/i.html?_from=...All-Categories

[DannyvG]

I think its a short between the windings directly not towards the stator. Because I did test it with a megger for shorts from wind to stator.
I got the tip from dekker to put a certain load, 3A or so on the wire and measure the voltage drop. In this way you can pretty accurately determine the resistance of the wire itself and you can check for wire length and thus shorts between windings.
And the best part is, it seems I can use my icharger for it because it has a DC motor test program and a foam wire cut program where you can set voltage and max amperage.

[HeliFX]

Nice

"One thing I am wondering about is where do you solder the esc wires, do you do that as close to the motor as possible or just twist up the wires and only solder the end?
Do you need to isolate all single strands or wont it matter that you twist them up against each other?"

As dekker as stated.

method I use now is very board twist maybe 2 or 3 twist with some heat shrink tube.
scrap insulation on tips, cover with glass braided electrical sleeving and solder ends

[DannyvG]

Originally Posted by djamgils

I did the second gaui motor yesterday but I have some problems with it.
When testing the 2 partial motors I get 1440kv and 6A no load for 1 side and 1600kv (with changing rpm) and 20A no load current on the other side.

I found the problem -> I am stupid
I failed to notice the second Gaui motor was a 8 pole and not a 10pole so I simply used the wrong wiring scheme. That partial motor that seemed to work correctly was actually terminated wrong so I was just lucky it did something reasonable.
I now rewind the motor as 4+4YY for a 8pole and it works very well.
nspec is 1590rpm/volt and both partial motors where within 2%
no load current is 5.5A.

This motor will be tested in a Trex500.
Next motor to rewind will be a 700MX in 7+7YY with required nspec of 470rpm/V for a logo 600.
I tried one group with 1.24mm wire but couldnt get it in properly. I noticed some tricks on powerditto and dekkers dutch topic to handle such things so I will try them but if I fail at that I will go with 1.12 or 1.18mm wire.

[HeliFX]

I did the very same mistake on my first rewinding motor

[Vinger]

Originally Posted by djamgils

I found the problem -> I am stupid
I failed to notice the second Gaui motor was a 8 pole and not a 10pole so I simply used the wrong wiring scheme. That partial motor that seemed to work correctly was actually terminated wrong so I was just lucky it did something reasonable.
I now rewind the motor as 4+4YY for a 8pole and it works very well.
nspec is 1590rpm/volt and both partial motors where within 2%
no load current is 5.5A.

This motor will be tested in a Trex500.

i have both the shorter and slightly taller Gaui motor, have not opened the taller one, but the short one has 12 poles and 14 magnetic poles. These two motors will be my first projects and am looking for about 1400 KV for both. Are you sure the taller one has only 8 magnetic poles? If so what winding pattern did you use for this? Thanks

[HeliFX]

Now that you've got one under your belt.
You can try 1.4 mm for the Align 700mx. I've done a few these motor and 1.4 mm
will produce some great results.

Originally Posted by djamgils

I found the problem -> I am stupid
I failed to notice the second Gaui motor was a 8 pole and not a 10pole so I simply used the wrong wiring scheme. That partial motor that seemed to work correctly was actually terminated wrong so I was just lucky it did something reasonable.
I now rewind the motor as 4+4YY for a 8pole and it works very well.
nspec is 1590rpm/volt and both partial motors where within 2%
no load current is 5.5A.

This motor will be tested in a Trex500.
Next motor to rewind will be a 700MX in 7+7YY with required nspec of 470rpm/V for a logo 600.
I tried one group with 1.24mm wire but couldnt get it in properly. I noticed some tricks on powerditto and dekkers dutch topic to handle such things so I will try them but if I fail at that I will go with 1.12 or 1.18mm wire.

[DannyvG]

Originally Posted by Vinger

i have both the shorter and slightly taller Gaui motor, have not opened the taller one, but the short one has 12 poles and 14 magnetic poles. These two motors will be my first projects and am looking for about 1400 KV for both. Are you sure the taller one has only 8 magnetic poles? If so what winding pattern did you use for this? Thanks

The shorter one that I have is completely filled with magnets back to back and there are 20magnets. But I presumed they are 2pairs and thus effectively a 12N10P motor

The taller gaui is a 12N8P so I used this scheme
http://www.powerditto.de/schema12N8PYY.html

Originally Posted by HeliFX

Now that you've got one under your belt.
You can try 1.4 mm for the Align 700mx. I've done a few these motor and 1.4 mm
will produce some great results.

seriously? did you get 7+7 in there with 1.4mm, you got some pictures of that?

I was looking at this page http://www.scorpion.powercroco.de/12N10P5035georg.html
and I noticed it says to first do everything with 6 winds and then finish with the 7th wind at the end.

Zuerst wurden alle Zähne mit je 6 Windungen versehen.
Gewickelt wurde jeder Zahn von innen nach außen um alle Enden außen zu haben.

Did he use the red, green or blue method for those first six winds?
http://www.powerditto.de/schemamodus12N_YY2/12Nz.gif

I also saw dekker doing something similar
http://www.modelbouwforum.nl/forums/...ml#post1991232

Because I now immediately tried 7+7 but that was just ugly


another attempt with different crossing

[Vinger]

Thanks djamgils!! Will have a closer look at the ones I have once home, work interferes with winding some test motors!!!

[HeliFX]

Sorry no pictures but possible

Align 700mx 11 x 1.6mm 550 kv
or
Align 700mx 12 x 1.5mm 500 kv

basically no room for error. Making your coils nice and tight and even