Big 24N questions (28 Pole) - RC Groups
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Apr 02, 2017, 03:51 PM
Maiden>Confident>Cocky>Crash!
argo-2's Avatar
Help!

Big 24N questions (28 Pole)


Hi All

I've scoured the forum but can't find an answer, wondering if you experts may be able help?

I've dissembled my MP12090 (manufacturers site: http://www.freerchobby.com/product_display.asp?keyno=68 ) with the idea of lowering it's KV from 101 to ~60ish via terminating it as a WYE.

It appears to be wound as a dLRK Evolution . Looking on the brilliant Calculator page ( http://www.bavaria-direct.co.za/scheme/common/ ) and on this forum, I can't see a way to re-terminate an Evolution to WYE (from the 'standard' Delta). Can anyone kindly advise if this is possible?

I may just re-wind this guy and be done with it, but I thought it was worth a shot to try WYE first if that was possible.

Some photos of the capellini spaghetti:
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Apr 02, 2017, 08:41 PM
Registered User
manuel v's Avatar
Maybe on picture.
3 wire left is Phase 1,2,3.
3 wire right are end end phase. (joint fore Y)
Apr 02, 2017, 09:18 PM
Jack
jackerbes's Avatar
I think Manuel has it right, if you enter 24 slots and 28 poles and choose Y at the wind image calculator you should be able to match it up. It is OK if the turn directions look like they are reversed as long as all of them appear reversed.

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

I would not be afraid to try clamping those three leads together and putting the other three leads on an ESC and running the motor. Just give it one or two clicks of throttle and if it starts and runs normally stop and make soldered permanent connections before running it at any higher throttle settings.

Jack
Apr 03, 2017, 02:20 AM
Maiden>Confident>Cocky>Crash!
argo-2's Avatar
Brilliant, thanks guys
I'll give that a go once I prise myself away from work!
Apr 03, 2017, 05:29 AM
Maiden>Confident>Cocky>Crash!
argo-2's Avatar
Well it ran but very 'hummy' with a lot of Amps. I tried various combinations but always with same result

I guess I'll try my hand at rewinding. Any suggestion for a particular winding scheme? Or just go with 'ol reliable dLRK? I did think that Half Parallel dLRK might be good, but for a 24N it might be just too complicated for my brain
Apr 03, 2017, 08:10 AM
Jack
jackerbes's Avatar
It would be nice to get the stator off of the bearing tube and look at the wiring closer, is that possible? The attached image compares them, the one from the generator has been flipped over horizontally and then vertically so I'm not positive I have the turn directions right.

Jack
Apr 03, 2017, 08:13 AM
Jack
jackerbes's Avatar
Here is the 24N28P-Y image before any flipping or turning. I use irfanview for doing that and it can really help with some conceptualizations...

Jack
Apr 03, 2017, 12:41 PM
Registered User
manuel v's Avatar
It is necessary to determine where each of the coils begins and ends.
From the photos, now I see that the winding is not the one that Jack put, which is the same one that I consider.

It is necessary to extend the wires to the place of origin. And then take a picture.
Apr 03, 2017, 01:25 PM
Registered User

find the start and end


wouldn't it be a sure thing to simply hook up a voltage to one group of wires and see where it comes out? a battery and a terminal at one side and a multimeter and the other terminal at one of the other bundles
Apr 03, 2017, 02:41 PM
Maiden>Confident>Cocky>Crash!
argo-2's Avatar
Welcome to my puzzle guys!

Spent far too much of the past weekend looking at this It may shock and surprise you to learn this motor has globs of epoxy on the windings, so unraveling to any degree is a one-way journey. However I did scratch down where the wires come out and have just transferred this to a diagram. Due to the way the spaghetti is wound/globbed, each termination has the appearance of coming out of a slot.

Attached are diagrams. As rightly pointed out, it is was very easy to check winding continuity and this is represented by the colours in my diagram.

As far as combinations go I have:

Checked original delta and its fine as (left to right):
Red/Blue: ESC 1
Green/red: ESC 2
Blue/Green: ESC 3

Attempt Y #1 (bad) left to right:
Short: Red/Blue/Green
Red: ESC 1
Blue: ESC 2
Green: ESC 3

Attempt Y #2 (bad) left to right:
Red: ESC 1
Blue: ESC 2
Green: ESC 3
Short: Red/Blue/Green

Various other combinations just because I could.

Strange! Many thanks for looking at this conundrum for me
Apr 03, 2017, 03:21 PM
Registered User
manuel v's Avatar
I insist this is so.
Apr 03, 2017, 03:36 PM
Registered User
manuel v's Avatar
Now, you say that it is originally?
Apr 03, 2017, 03:36 PM
Registered User
manuel v's Avatar
Then this could be an option. And viceverza.
Apr 03, 2017, 07:58 PM
Jack
jackerbes's Avatar
@ argo-2

You have six bundle ends on the motor right?

Take a DMM set to Rx1 and put one probe onto one of the three ends that are to the right and then check the other ends for continuity. Repeat that for the other two ends and you should be able to isolate the three starts (on the ESC leads) and their ends (joined in the Wye bundle).

As you check those touch all of the leads to verify that none are shorted to one of the others. And touch the housing to make sure you have no shorts to the stator.

Jack
Apr 04, 2017, 06:38 AM
Maiden>Confident>Cocky>Crash!
argo-2's Avatar
Hi Guys, I'm not going to get time to look at this tonight as I have a plane to catch. Thank you again for all your tips and advice. Perhaps when I get back fresh eyes will show me to have made a dumb mistake, wouldn't be the first time

@jack - Yep to 6 bundles. And yep, I used a continuity meter to determine what's what and also checked for shorts. That how I colour-coded that little picture. Its just so darn hard to see where the wires go with everything so thoroughly glued down!

@manuel - I'm sorry I don't follow your 3rd and 2nd to last posts, what are you 'insisting'? However I certainly understand your last post and I very much look forward to trying that configuration when I get back


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