Discussion Turnigy T600 880kv Delta to Wye help

 #1 mattyhawk Jun 07, 2011 09:53 PM

Turnigy T600 880kv Delta to Wye help

5 Attachment(s)
So I did a bit of a search, but wasn't finding adequate answers to my question in previous posts.

I have a Turnigy T600 880kv. It has 12 Tooth and 8 Mags, 8 Turns with a measured 900kv actual.

I was planning to rewind it to 500kv, but in my motor winding infancy, I realized it is a delta wind, so I could change it to a wye termination and get to about 550kv. This would work for me.

I took the motor apart tonight and came across something I'm stuck on. Hopefully I can explain myself adequately. I assume there is some directionality that the winds need to be oriented for wye terminate. It is easy enough to find out which leads are the start and finish of each wind, but how do I determine which end of the wind to use? Does it even matter? Do I just trial and error test it in various connections 'til I get it right?

Thanks for the help!

Some pics for your viewing pleasure:

 #2 Ron van Sommeren Jun 08, 2011 01:02 PM

I take it you are an EE of some kind?

edit June 09: oops, this is star -> delta, not delta -> star
The former Star-point connections are the Starts, the former battery-connectors are the Ends:
E1 connects to S2
E2 connects to S3
E3 connects to S1

You can play a bit with Delta/Wye using the winding diagram calculator, graphical output and you'll see the changes:
http://www.rcgroups.com/forums/showt...ght=calculator

Otherwise trial and error with an oscilloscope until you get 120degrees phase difference.

Vriendelijke groeten ;) Ron
diy motor groupRC flight club
Drive Calculatordiy motor tips

 #3 mattyhawk Jun 08, 2011 03:17 PM

Quote:
 Originally Posted by Ron van Sommeren (Post 18449936) I take it you are an EE of some kind?
Haha, nope, does a Biologist count? :D

Quote:
 Originally Posted by Ron van Sommeren (Post 18449936) The former Star-point connections are the Starts, the former battery-connectors are the Ends: E1 connects to S2 E2 connects to S3 E3 connects to S1 You can play a bit with Delta/Wye using the winding diagram calculator, graphical output and you'll see the changes: http://www.rcgroups.com/forums/showt...ght=calculator Otherwise trial and error with an oscilloscope until you get 120degrees phase difference.
Excellent. Thanks!

 #4 Ron van Sommeren Jun 08, 2011 04:40 PM

Quote:
 Originally Posted by mattyhawk (Post 18451220) Haha, nope, does a Biologist count
Let's not open that can of worms, shall we? :D I can hardly handle having a resident geologist in this subforum.

Quote:
 Originally Posted by mattyhawk (Post 18451220) ... Excellent. ...
Alas, no :( I described changing from wye to delta, whilst you want to change from delta to wye. But I think you get the gist, even though you're not an EE, just reverse my instructions.

Vriendelijke groeten ;) Ron
diy motor groupRC flight club
Drive Calculatordiy motor tips

 #5 mattyhawk Jun 08, 2011 05:50 PM

Quote:
 Originally Posted by Ron van Sommeren (Post 18451967) Let's not open that can of worms, shall we? :mrgreen: I can hardly handle having a geologist in this subforum.
LOL, does Kiwi know how you feel? :D ROTFL

I swear, EE's first class in college is "Intro to Life Science and why they aren't really scientists". My father in law is a retired US Navy R&D EE, and I get the same jokes from him. He like to joke with me how biologists are biologists because they are only good at memorization. Engineering is a thinkin' man's profession. :p So I tell him without me, he wouldn't know what genus and species of bird his widget just killed. Haha, good times.

Fortunately for me, he helps me quite a bit in the area of circuits.

Quote:
 Originally Posted by Ron van Sommeren (Post 18451967) Alas, no :( I described changing from wye to delta, whilst you want to change from delta to wye. But I think you get the gist, even though you're not an EE, just reverse my instructions.
Yeah, I saw that, but it still gave me what I needed to get started (in reverse).

I gotta borrow an oscilloscope from the lab downstairs and get on that. It helps I work with a bunch of engineers, but they are mostly structural, chemical and environmental. I'll say one thing about engineers, they have the best toys!

 #6 jackerbes Jun 08, 2011 05:59 PM

1 Attachment(s)
You have six bundle ends on the 12 arm stator so it is a DLRK wind.

The six ends are gathered and joined as three pairs. And, of course, there is no Wye bundle.

Delta System (what you have now)
Point 1: Solder S1 and E3 together
Point 2: Solder S2 and E1 together
Point 3: Solder S3 and E2 together

Note: Point 1, Point 2 and Point 3 are connected to Electronic Speed Control (ESC)

To change that to the star or Wye system:

Star (Wye) System
Solder E1, E2, E3 together
Note: S1, S2 and S3 are connected to ESC.

Just to make sure we are reading from the same sheet of music, you can look at this kit motor assemblhy instruction manual:

And see exactly how the phases were wound and how they are terminated. The stator arms are arbitrarily numbered 1 through 12 in the instructions and you can see the which arm number each phase starts on and ends on. So if you separate your three pairs into six separate ends and use an Ohm meter you can check to make sure where the starts and ends are.

The attached image shows how I think you will find the motor to be wound but, of course, it may be different and this might not work for your.

But if it is the same then it is just a case of joining the three "End" ends together to make the Wye bundle and putting the ESC connectors on the three remaining "Start" ends.

Jack

 #7 mattyhawk Jun 08, 2011 08:40 PM

That is some good stuff there Jack. One thing though, the designer of that komodo motor shows it in a 10, 14, or 16 mag motor by design. Would this turnigy not be in an ABCABCABC wind with the 8 mags?

 #8 jackerbes Jun 09, 2011 07:16 AM

Quote:
 Originally Posted by mattyhawk (Post 18453729) That is some good stuff there Jack. One thing though, the designer of that komodo motor shows it in a 10, 14, or 16 mag motor by design. Would this turnigy not be in an ABCABCABC wind with the 8 mags?
I missed the magnet count in the photo. But you're right, it probably is an ABC wind.

That manual at the link shows the ABC wind in Appendix II and also has the Delta and Wye terminations for it. It says it is for the 16 magnet install but it works with 8 magnets too apparently. So I think you can still figure out the starts and ends with a meter.

I guess the DLRK wind can only be done on the 12 arm 14 magnet motors. I'm still getting older and smarter on motors... :o

Jack

 #9 mattyhawk Jun 09, 2011 09:49 AM

Sweet. Makes sense the 16 mag would be similar, didn't think about that.

I guess I have what I need to make this happen. Let's see what comes of it, shall we?

 #10 jackerbes Jun 09, 2011 11:05 AM

Good luck with it! We'll be looking forward to the details.

Jack

 #11 Ron van Sommeren Jun 09, 2011 12:31 PM

Quote:
 Originally Posted by mattyhawk (Post 18452532) ... I swear, EE's first class in college is "Intro to Life Science and why they aren't really scientists". ...
OTOH, I chose 'Signal propagation in nerves' as one of my MSc classes. A very 'mathy' model that is.

Quote:
 Originally Posted by mattyhawk (Post 18452532) ... I gotta borrow an oscilloscope from the lab downstairs and get on that. ...
Drive motor with a power-drill and it will act as a generator and connect to the oscilloscope.

Quote:
 Originally Posted by jackerbes (Post 18456593) ... I guess the DLRK wind can only be done on the 12 arm 14 magnet motors. ...
Only because it's so by name/definition. 'LRK' stands for Christian Lucas @RCG (huge e-motor design @www.magnet-motor.com), Ludwig Retzbach and Emile Kuhfuss. They did the original diy brushless motors articles in the German ElektroModell magazine in 2000. And those motors had 12statorpoles and 10/14 magnetpoles.

Original ElektroModell LRK articles, translated into English
http://www.aerodesign.de/peter/
-> LRK English
-> 4 EM 2000 articels at bottom of page

Vriendelijke groeten ;) Ron
diy motor groupRC flight club
Drive Calculatordiy motor tips

 #12 mattyhawk Jun 10, 2011 10:36 PM

1 Attachment(s)
Quote:
 Originally Posted by Ron van Sommeren (Post 18458982) OTOH, I chose 'Signal propagation in nerves' as one of my MSc classes. A very 'mathy' model that is.
That looks like a fun class!

Following picture is for my reference. Testing the motor out tonight. Looks like this is going to be a simple as it gets.

:popcorn:

 #13 jackerbes Jun 11, 2011 06:31 AM

Good for you, looking forward to hearing how that goes.

If you look at the different winding schemes for a 12 arm motor here:

http://forumrc.alexba.eu/nutpol_e.htm

The colors on that chart rank the different winds by how well they work, the key is:

"..black- does not work, blue - good combination, white - it works, red - it works, but not very well..."

So you'll have the red "it works, but not very well" wind. If you want to mess with the motor more to make it even better, you'll still have the option of going to 16 or 14 magnets and getting to the better winds.

If you like the lower Kv motor better, you can even get more power out of it by going to 16 magnets later. That will be more work though...

Jack

 #14 Ron van Sommeren Jun 11, 2011 10:07 AM

In fact, winding diagram does not matter, only the Start and End of a phase wire. What 'happens' between Start and End is not relevant for star versus wye.

Jack, that table is also available on Ralp Okon's diy motor building site
translate...www.powercroco.de
-> Construction
-> Combination chart.

Prettig weekend ;) Ron
diy motor groupRC flight club
Drive Calculatordiy motor tips

->

 #15 mattyhawk Jun 11, 2011 08:19 PM

Alright, conversion went relatively smooth. I decided to just chance my esc and guess at the correct combination. I was relatively simple as there really are only 2 ways to separate the wires. Problem though, maybe you guys can help me decipher the following information.

Unfortunately I do not have a solid state adjustable power supply. I will get one eventually, but my batteries will have to do for now.

I also replaced the bearings with semi ceramics.

I took two measurements of the new KV.

V= 11.43
Io= 1.68V
RPM= 5400

V= 15.16
Io= 1.8
RPM=7150

I am seeing about 472kv and relatively the same Io, which seems wrong to me. That means the difference in KV factor is 1.92, and I was expecting about 520kv. I would expect the bearing change to help rpms and lower Io. Did I screw something up? Is it possible this is an esc issue? Maybe wrong timing? Thoughts?

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