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Electric Motors Winding and Repair Electric Motors Winding and Repair Discussion


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Old 03-17-2016, 12:15 PM   #1 (permalink)
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Default LMT torqstar 7025

got a defective 7025 torqstar into my hands.
it is short just with 12V.










SPS winding is made with 16 turns from 3 drilled wires into parallel.
switching is done with a board.

there seems to be only a very thin capton foil between coil and statorpackage.

winded hammers are 5mm broad, the slots 2,5mm.
slots are 8mm deep. inner ring is 3mm.

the 20 magnetpoles are oneparted with 8,8x3x25mm magnets.
they are mounted into very flat slot into the 2,7mm backiron.
no traces of a balancing process into the can.

bearings have 29mm outer and 12mm inner diameter for the 12mm diameter shaft.
I'am looking for an idea to find out the defektive coil without cutting all the solderings.
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Old 03-17-2016, 06:12 PM   #2 (permalink)
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The wire reminds me of
www.smitdraad.nl/index.php/our-products/ctc/ctc-details

Vriendelijke groeten Ron
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Old 03-18-2016, 06:50 AM   #3 (permalink)
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Yes twisted multistrand. I wonder if there was a specific number of twist per foot like Litz?
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Old 03-19-2016, 12:27 PM   #4 (permalink)
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At first I was thinking maybe you could pick up signal strength off a scope based on a emitted signal at a frequency chosen appropriately and brought near each coil then picked up by one end of the wire but then I realized you were looking for a short not a break. Ohm meter sensitive enough to differentiate an extra coil? Basically compare all the coils in and out. The short will be present throughout but maybe enough of a discrepancy to isolate the faulty coil. Just a thought.
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Old 03-22-2016, 06:53 AM   #5 (permalink)
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Maybe too late now but considering the price and quality why not send a "defective" motor back to Lehner? They have all the tooling to isolate de-solder and remove the bad coil and simply replace it .
U could try a wire tracer to find the fault but reproducing the single coil with the same dimensional twisted strand may be a challenge.Not doing so will change the fill factor of the replaced coil.
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Old 03-22-2016, 09:45 AM   #6 (permalink)
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it will run for shure also with unpressed not twisted wire - it is still only a motor.....

http://www.sinusleistungssteller.de/FuriaOne2012.html

have you found some evidence, that the 3-strand twisted wire works soooo much better than single strand?

I was primary interested in meassuring the motor.
mechanically and electrically.
data have been interesting for me and they showed the expected.

was btw. also very interesting to get all the needed real dimensions, if someone wants to copy the "radically new and vastly superior concept".
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Old 03-22-2016, 11:17 AM   #7 (permalink)
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U don't need evidence to know if u take two or 3 parallel strands and twist them that the length becomes shorter than if they were not twisted but the same amount of copper is there.Try it..... To get the same number of turns will require more wire length and thus will increase the dc resistance . Also it is fact that the twist pitch, number of conductors, and their diameter alters the conductors frequency response characteristics and can also reduce the ac resistance when mathematically applied correctly. I posted the link some time ago in another thread.I will find it and post it again if you need but certainly you'd want the coil to be identical in copper fill resistance etc. to the others. I would also like to add after further investigation that the cross section in such a bundle cuts slightly obliquely across each strand in the bundle so those cross sections are slightly elliptical further increasing the dc resistance making it even higher than that that would been seen in a straight lay counterpart.The measurement device shown can find a fault and it cost half a stack.... $500.00 USD when Lehner would likely repair for no cost if it is indeed a defect I would think. If it was an engineered twist the number of strands diameter of the strands and pattern of twist could all play a part in the overall performance characteristic of the coil. Just seemed intuitive to me that if you wanted a way to measure a shorted coil you'd also want to replace it with an electrically and mechanically identical one. Not at all a radical or a new concept to want to replace a damaged part with an identically functioning undamaged one. Certainly what would happen with a factory return on a defect.
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Old 03-22-2016, 03:37 PM   #8 (permalink)
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Quote:
Originally Posted by powercroco View Post
it will run for shure also with unpressed not twisted wire - it is still only a motor.....
www.sinusleistungssteller.de/FuriaOne2012.html...
English version of their Torqstar problem.
With some nice and impressive solar boat racing videos in a very north-Nederlandish (Friesland) setting as well
www.sinusleistungssteller.de/en_FuriaOne2012.html

Testing an SLS controller calibration/tuning
40inch prop




Vriendelijke groeten Ron

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Old 03-22-2016, 03:52 PM   #9 (permalink)
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Quote:
Originally Posted by ron_van_sommeren View Post
English version of their Torqstar problem, with some nice and impressive solar boat racing videos in a very Nederland/Friesland setting as well
www.sinusleistungssteller.de/en_FuriaOne2012.html


Vriendelijke groeten Ron
Nice Ron,
Very encouraging link for hand winders to read perhaps... if they ignore the report details it contains about the potential issues, lack of full power, and additional damage encountered by this particular alternative winding attempt on this high end motor with other than factory specs when it was all said and done. But it worked.... Technically speaking if the motors end plate put it in a wye configuration the motor could work inefficiently without a coil connected at all. So one could have quite easily not been able to see a microscopic cold joint or hairline fracture in the solder joint with the naked eye and that could create similar diagnosis on some test equipment.
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Old 03-23-2016, 07:43 AM   #10 (permalink)
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Here is another interesting video sent to me from Germany showing the power of stock LMT Torqstar outrunner running 12-18 kw for 40 min durations. You can see the motor installed around the 3:18 mark.

Enjoy.

Lampuga electric jetsurfboard (5 min 7 sec)
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Old 03-26-2016, 01:03 AM   #11 (permalink)
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the motor I had for examination has no airchannels inside statorholder just like the one into the link.

also don't know, why they don't use the so much better working segmented magnets or stacked backiron in this high-end concept.

btw.: as more solderings, as more sources for microscopic cold joint or hairline fracture in the solder joint or problems into the platine.

in a special use (another motor) we had broken wires at the soldering points near at the platine - may be by mechanical resonances.
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Old 03-26-2016, 03:15 AM   #12 (permalink)
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I don't know why as those are proven things that work but Their motors are already making much more hp than any other outrunner on the market so for them why increase the price point when the performance and price are already more than any average modeler would ever ask for? Much easier to just except Litz truths about this particular motor special wire processing or why not wonder why the surfboard company after reviews of many different great motor concepts threw them all out and landed on Lehner who just plain makes more power .Alot more and a lot longer. Good solder joints can show lower resistance than the wire itself so its no real detriment. The end plate is multi layer so a good bit of copper there. It would be better in resisting skin effects than large mono wire and in a WYE will probably handle the possible higher triplen currents seen on the neutral lines. Creating larger than the phases neutral conductors traditionally would be quite a challenge without the use of solder. A poor solder joint will always create a problem. Seeing a convex fillet around the wires verses concave one is usually a tale tale sign of a bad solder joint. These on the Lehner appear to have possibly been done by a robot and seem to observe a spec grade but still a stereophonic microscope is used to look at such things if you think it is a possibility. I only use ROHS high temp silver bearing solder on my bundles or single coil winds. No problems thus far with it but balancing always has a place in reducing mechanical resonance....though some feel it isn't necessary or just plain wise. A superior machining and gluing process may not need balancing but we all know brands that are poor in these departments so they do.

If its not a bad solder joint what have you come up with as a solution to replacing a single coil?

Edit.....
Had? did you send it back?
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Old 03-26-2016, 06:43 AM   #13 (permalink)
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I think, it's enough of advertising now.

reading the words comming from CL, someone could think, you are paid by them!
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Old 03-26-2016, 08:59 AM   #14 (permalink)
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Without touching the preposterous propaganda I'll tell you these are engineering principles that any person can read for themselves. There's nothing new about solder, diagnostic equipment, Litz or anything about the plethora of English papers on the subject sofa that needs a German interpreter . If you cannot simply accept real answers to your questions of how to find the coil and replace it with an identical one it is what it is. Go ahead and wind one single coils with your large strand and post head to head with original Lehner. That will certainly tell u what you wanna know if u don't already know with the world that Lehner is an excellent motor beside any. Or maybe you can see no conspiracy in your own posted link and trust the words there as you posted it.... U should read it in its entirety, but then why ask if u know? Lehner and Neu motors holds numerous world records in my hobby . What does Chris need to tell us? What has he told you? In my hobby those two have clearly stood out as the best year after year and still the surfboard companies could not get the other offerings from other manufacturers to hold up. Just the facts I was made aware of no need to hate the messenger it's only fair discussion. Who am I advertising for....lol I'm certainly not affiliated with any company at all so if anything u can trust of all involved I'm the last one trying to sell a thing here.

To make sure we are clear I've included from one semester just one course 3 hours class then 2 hours lab twice a week . U see photos of all the damn labs and empirical research I had to do to earn my engineering degree? I dont need Fabian..... I have shelves full of such work an entire room. Then 25 years of working with linear motors and controls before forums even existed.Thank you all knowing but I'm sorry to inform that You nor Peter, Stefan, or Chris, have a damn thing to do with the non proprietary knowledge in my head. I busted my ass for it! and I choose to share it. So now that the ad hominem is placed back in the spam folder where it belongs the on topic honest truth, without personal insult,is that the idea World Class Lehner needs to be re engineered to Powercroco Scorpion mono wire standards is really something to ponder.
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Old 03-27-2016, 09:19 AM   #15 (permalink)
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Hi,

nothing to worry about . It is only a typical Okon tread ,he is clapping his owen shoulders.
1BOHO is well educated and has much moore know how about such coils and soldering than we all and can speak for himself no need of feeding him.
This is a free forum not like the powercrocoforum where all are advised nothing to tell about the mysterie kitchenlabs.
Wonder wy you are spending a closer look at this motordesign ? maybe the burn 7050 motors ,you scale up force you .
But it's to late for education as there are no teachers for you .
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Old 03-27-2016, 01:59 PM   #16 (permalink)
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Stay civil gentlemen ! Your work and knowledge is fascinating for us to watch and learn from and a great benefit for forum readers, who, like myself, will never come close to understanding the profound science in the multi vs single strand debate! We don't look for winners but the debate is fascinating and should be kept free from a contest
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Old 03-27-2016, 02:44 PM   #17 (permalink)
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Quote:
Originally Posted by CHX2 View Post
Hi,

nothing to worry about . It is only a typical Okon tread ,he is clapping his owen shoulders.
1BOHO is well educated and has much moore know how about such coils and soldering than we all and can speak for himself no need of feeding him.
This is a free forum not like the powercrocoforum where all are advised nothing to tell about the mysterie kitchenlabs.
Wonder wy you are spending a closer look at this motordesign ? maybe the burn 7050 motors ,you scale up force you .
But it's to late for education as there are no teachers for you .
This is not a free forum, it is a private forum where visitors are allowed to access conditional on the principles it was founded on and the policies of its current owner - mutual respect is a major component of these principles. If Dr Okon owns his own private forum then naturally he is at liberty to run it along the principles he chooses!
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Old 03-27-2016, 02:56 PM   #18 (permalink)
 

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As John said, keep the posts civil or lose the privilege to post.

Quote:
Quote:
Originally Posted by powercroco View Post
I think, it's enough of advertising now.

reading the words comming from CL, someone could think, you are paid by them!
Please keep the discussion about the technical aspects and refrain from judgmental commentary.



1BOHO
Respond without attacking the posters here on HF.


Quote:
Thank you all knowing but I'm sorry to inform that You nor Peter, Stefan, or Chris, have a damn thing to do with the non proprietary knowledge in my head. I busted my ass for it! and I choose to share it. So now that the ad hominem is placed back in the spam folder where it belongs the on topic honest truth, without personal insult,is that the idea World Class Lehner needs to be re engineered to Powercroco Scorpion mono wire standards is really something to ponder.
I won't restate this.
Since you have a history of disrespectful posts, this is your one and only warning to again, cease this practice or again, lose the privilege to post.


Thanks in advance.
Mike

Last edited by TowPilot; 03-27-2016 at 04:21 PM.. Reason: Equal time for each participant :)
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Old 03-27-2016, 04:36 PM   #19 (permalink)
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And still all the physics and science behind it remains the same... Beautiful one sided debate in my opinion as there never any supporting evidence from the other side but speedplane motors wound with big mono wire from one company the word of a person with no formal training and data log readings pushing plane props. No harmonic data temperature readings or anything else just that. So scientist waste alot of time then with controls and stuff wouldnt you say? Any one versed in excel can create a plot to say whatever they want it too. The plethora of thesis however are compiled through vast scientific process calculations etc. and receive academic review from many pre exposed before publishing. Forum accolades and running a motor on a data logger is a far cry from this. I don't see any worthy debate myself as all the principles and ideas are shared and have been proven in engineering consortium's like IEEE....... The largest in the world. One guy and his large mono winded motor is going to trump this? If so then their should be a seminar given to bring all these phd's and masters manuals up to speed. The idea that the twist means nothing is gross over cite and doesn't need to leave any reputable motor winding forum without re direction. Nothing comes out opposition censorship in these type threads but scorpion is superior to all others and its just a flat tale..... When people go on senseless dribbles about magnet segments etc they are calling out Gerling and numerous Phd's in and Masters in the field while they are who? No one else is responsible for such foolish self impalement . When all the principles are well thought out and applied correctly by those with the right tools and know how you end up with a motor that can push the surfboard. The entire point. Motor development specifically for only cared about speed planes would not likely have much bearing on what would make a good surfboard motor anyway. Totally different conditions and loading in the first place. This was never a debate about multi strand or mono it was about identifying and replacing a highly engineered LEHNER coil with an identical coil by hand and the facts are as they are. You cannot!!!! So rather than accept it and send it back I tell u all the motor is inferior and needs my improvement when in actuality the probability of sub par performance is likely in such attemps and already been chronicled in one such attempt. If there is a debate it is certainly an asinine one.
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Old 03-27-2016, 06:22 PM   #20 (permalink)
 

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I said to refrain from attacking members.
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