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glad you lot have sorted this one out between you. I *think* I see the light, only it's not bright white, it's more a murky light with a few dribs and drabs of fog in front
How about I wind one and you tell me if I'm going about it right?! |
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Brad |
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Last edited by arx_n_sparx; Sep 03, 2004 at 09:44 AM.
Reason: edited out a mistake
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Not so sure about this one though. I can see what Ron is getting at, but I suspect it should be ABCabc = aBcAbC ... and this would be as you see the start/finish epic Brad, but not my method. Brian .. Ignore my comments please. We will talk monday |
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Last edited by Mr DIY; Sep 03, 2004 at 09:59 AM.
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Brian: I understand your point now, but it seems to me that you don't understand mine. Take 17 Tylenols™ and read through what the posts say. Nah, I wouldn't want you to hurt yourself - make it 15 "Meanwhile, back at the ranch" (this is another weird expression - don't ask) I think I will try to find an ostrich farm so that I can bury my head safely. If it's covered in sand, the risk to the public is low when it explodes..... Brad |
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[QUOTE=Eljimb0]I would like to add my thanks to Max as well. However Max's assembly procedure winds all teeth in the same direction and then connects the leads to each tooth to accomplish the desired pole (N/S). It clearly works but it leaves the door open for potential misinterpretation. Can somebody familiar with LRK give the definative star (Y) hookup of the six wires. I know what Brian is saying and I believe he is correct. In the past I tried (123 together) (4) (5) (6) as the three inputs and it worked poorly. From my experience I concluded that the star hook up just sucked. The drawing below is the LRK winding tecnique ABCabc. It is not for debate. thanks
jimbo jimbo, My additions to your posted sketch. This is the way I have wound and hooked up my 31.5 mm LRK's. However, I have never used Star (Y) for any of my finished motors as they performed poorly. If I tried to maximize the torque by minimizing the air gap and connecting star the motors exhibited more heating and reduced efficiency. I now use only delta and .5 mm minimum air gap. I believe this is why you do not find star connections for 12 (6 wound) tooth, 14 magnet LRK's. You can find star diagrams for 6 tooth stator with 4 or 8 magnet rotors. BobK |
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Last edited by Skinner46; Sep 03, 2004 at 04:42 PM.
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Bob,
My experience with the wind you described was the same as your's. Not much power, more heat than expected. That is why I have been interested in Mr. DIY's finding. His explanation complete with oscilliscope data is too far out for a simple carpenter/musician/artist like me to fully comprehend. I realize I could get myself up to speed on electronic engineering with a few good books and a concerted effort....But..... I am just interested in getting the answer out there. thanks, Isn't this great jimbo |
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Brad ... ignore my post no 48 as said in edit. Too late on Friday for that one
Skinner46, now you know why your Star motors performed poorly. As I said earlier in this thread, I wander how many people have wired up a STAR LRKs incorrectly and don’t know it. Eljimbo … that goes for a Mr Matlock on Yahoo groups as well. Would you agree that the answer you got does not = max.ferra's explination? The answer to the Eljimbo's diagram question is simple. As all teeth are numbered 1 to 12 sequentially, you do not need any reference to ABC notation or to know which wires are starts or ends as we all agree than an LRK can only be wound one way .. or it is not an LRK. How you wind it, being by notation or a diagram makes no difference, as long as we all end up with same looking windings scheme that would create North and South poles on opposite teeth. So take every second wire and connect it to a center point. That could be 1,3 and 5 or 2,4 and 6. In Brad’s terms, Tooth numbers 1,3 and 5 would be the starting points for each winding and the notation for such would be AbCaBc. So Brad would be saying, connect the ‘ends’ together. If you like to keep all your ‘starts’ on one side of the stator like me, the notation would be ABCabc and you would connect teeth as detailed already. Whose form of notation is correct though, well we could probably argue for many more hours, but I think we should have a poll somewhere on these forums and let people vote on it. Brian |
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I think I might see the problem.
If that last diagram works for you, it is because one of your "starts" is effectively an end. I noticed in one of the diagrams that Mr. DIY posted (post #23) he didn't wind consistently. In the LRK diagram, the starts of each leg of a stator always begin at the hub. In the DIY CAD diagram, he would start a wind from the end to the hub, then continue on the opposite side and start at the hub and finish at the end. Its not wrong, but not the way a motor is usually wound. As I said, the published diagrams are correct and work properly. If they aren't working I would always suspect that you didn't wind according to the diagram. Rick. |
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Last edited by rpage53; Sep 06, 2004 at 05:14 PM.
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How do you insulate the wire from the stator edges? I'm rewinding an AXI 2820 (equivalent to TM280-20) and can't seem to insulate the stator properly from the copper... 3 layers of Kapton and 2 layers of masking tape, and it's still shorting!
I need all the space I can get, winding 15 turns of dual 0.55mm diameter wire isn't easy... |
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Last edited by simingx; Sep 07, 2004 at 10:49 AM.
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After a little real thought and study, I agree with Brian (MrDIY). If you look at the drawing below, consider the following. If we assume that where the current enters each phase is a South Magnetic Pole and where it exits (the star center) is a North Magnetic Pole, then it becomes obvious the only way you can achieve 120 electormagnetic degrees between Phases is to connect as both Brian and Max have indicate. I obviously made my error by looking at the stated combinations ABCabc winding and assuming ABC were all "starts" and abc were all ends. This obviously is not true!! Bob K |
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an start/end and "a" does not mean an end/start. We may need to get back to some definitions here. The chart that shows the alphabet soup on winding motors to the best of my knowledge uses this convention. A=wind the stator tooth, looking at it from the outside-looking at the hammerhead, in a CLOCKWISE direction. a=wind the stator tooth, looking at it from the outside-looking at the hammerhead, in a COUNTER-CLOCKWISE direction. A sequence of ABCabc only gives the sequence of which tooth is wound in which direction and A/a, B/b, C/c referring to which "phase" is being wound. Also, correct me if I'm wrong here Ron but for a 12 tooth stator LRK motor this wind sequence would actually be written as A-B-C-a-b-c-, where the "-" indicates an unwound tooth. From Skinner46's post it's just starting to sound like we have some people using one definition and others using another and because of that the confusion keeps growing. In my reading on R/CGroups my understanding was that the abc's was only a shorthand notation as to which tooth was wound in which direction. It's only shorthand guys, don't make it any more than that. Maybe looking at MrDIY's picture from post #52 this way will make more sense. The second picture I think was also posted be MrDIY earlier. Okay, now I've probably muddied the waters even more, but please let's see if we can get to calling the same things by the same name. And Ron K, I'm not trying to rag on you at all but your comment raised a red flag to me and want to see if this may be the problem here. Oops, looking at your picture again, by definitions I've picked up, I'm seeing all stator teeth wound in the same direction-ccw. Here we go again! Martin Sorry, I got the pictures reversed. |
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Last edited by Martin C Wendel; Sep 08, 2004 at 02:01 AM.
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hey guys the GB 25mm 12 pole stators will be available in the next 24hrs from GoBrushless
GB 25mm 12 pole stator, 24.98mm outer diameter 9.3mm inner diameter 1.73mm thick 10 plates $0.90 ea phil |
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Last edited by Happy|Harry; Sep 08, 2004 at 11:11 AM.
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Last Time
I'll try one last time to offer some clarity. The LRK winding diagrams and their associated Y-Star connections are correct.
However, I keep seeing other people posting diagrams that without exception are wound differently. The LRK diagrams (and the way I have always wound) start every winding on every leg at the hub (center, middle) of the stator and end at the end (outside, periphery). These self-made diagrams start and end on the periphery -- I'm not surprised that they require different connections. Skinner46 did the different winding. Hope this helps, Rick. |
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