Super simple stator coil protection!

[snakeX2]

OK, i have wound this one CD-motor more than thirty times now and still i have been having shorts against the stator. I was a complete motor winding newbie before and now i feel quite confident even though the motor has only worked once (that was the first ever wind, all the rest have resulted in shorting with the iron stator). I have tried coating it again and again with (pink) nail varnish, tried winding it slowly and loose, quick and tight, made sure the wire going to the next stator was loose and so on. I have a go each day when i feel confident and ususally i find the problem after winding the three phases.
Today i started finding out what caused the problem and began wind a single stator and still everytime i had a short. I even pushed the coil away from the ends but :censored: .
The nail varnish coating is very thick and rather squidgy but when testing for a closed ciruit by pushing the tester pins into a random stator area, there is no connection. I am totally confused and now i know how to wind a stator well as i have done it sooo many times :o .

THEN i fought up this new method; using those food bags as an under-lay when winding those darn coils. Its very thin, flexible, and doesn't cause any problems when winding. NOW it should work, i have had so much trouble winding this stator :rolleyes: .
Good idea or not?

[snakeX2]

:D , I have never wound a stator so quickly, and neatly. I'm sure i could do better with the neatness but i couldn't wait to see if it works. There is no shorting at all and i felt much more confident to pull it tight and push the copper towards the centre to make them more neat.
I guess i'll need to cut away the rest of this bag and place another as the bag material is too tight for another phase of windings. Probably will have to cut all excess material ways afterwards but leave the material around each stator for maximum protection. :)

BTW, i didn't take more than 5 mins to find the first phase, if your looking at my time of first post to the second. Just check the conditions of lighting from picture A to picture B and you'll see. Boy it does get dark early ;) .

James,

[ecologito]

James, it looks pretty cool, I have a question that might be answered once you test the motor, won't the bag will burn once the motor warms up?

[mohillbilly]

it should be alright it might melt abit but will just keep things tight and many people coat the inside of there motors. as long as it protects his winds it did its job.

[snakeX2]

Yes, i got the final wind on. I found another short but that was with the loose end against a tiny corner of bare-metal that was showing, typical!

In the end, i have found it most easiest to apply one bag, single layer only of course. Push the bag material into the gaps and keep winding, trim the bag last. Maybe even after soldering wires just to be extra safe.
Thanks,

James,

[mohillbilly]

Good luck, let us know!

[birdofplay]

Have you RE Used the same wire each time?
If so, the coating might be breaking down after so much use.
Dont stretch the wire whatever ya do, Aa that'll bust the insulation fer sure.

You did say you got it right the 1st time, right ?
1 out of 30 sound like a REAL poor percentage.

Next, how about taking a Small Very Fine Stone on a LOW SPEED Dremel setting
and just smoothing off all the sharp corners.
Then do the epoxy/nailpolish/whatever coating (thinly )
Or your plastic bag idea

Just a thought while waiting - My Komodo stuff hasnt arrived - yet !

[snakeX2]

:censored: :censored: :censored: :censored: . Yup i'm giving up. I've tried everything, checked for shorting. OK. Soldered up the wires and it :censored: :censored: :censored: shorts again. I pushed, pulled the wires in every direction but by then i knew it was useless. I think this stator is cursed. I gave the stator and coils one last, slow death; i grabbed a great dirty knife and spliced every single strand of wire and slowly yanked it off in the grasp of my needle-nose pliers. Sorry for that outrage, I feel midly better now.

I'm gonna keep the (now pink, scratch and burnt) stator as a reminder of how i couldn't somehow wind my first stator. It'll comeback to me someday and i'll laugh on it.
Gooday :censored: .


James,

[olmod]

mmm I have been that route also ,very frustrating ,the crocodile motor build thread has some suggestions worth trying ,for me what works everytime is the right diameter selection of a thin walled heatshrink, cut it a little longer than the depth of the tooth, then as you shrink it hold the end against something(wooden block)to keep a little pressure on the end of the heatshrink so as it is shrinking it will actually cover the valley as well when cooled trim off excess around the head face with a razor blade. cheers :)

[snakeX2]

I also thought about using heat shrink. Hmmm, perhaps as an alternative (i don't have thin heat-shrink) i could just use some thicker plastic material such as black bin bags; that material is slightly thicker than the food-bags. If that don't word, wow i think i'm gonna go nuts!!
Thanks for the suggestion.

James,

[olmod]

Battery pack makers have the shrink.

[jbatch]

http://products3.3m.com/catalog/uk/en002/healthcare/hospital_community/node_CKRGFMCB7Wbe/root_K3BHNB8005gv/vroot_KQ98DZHKZ4ge/gvel_P7FT9L23G3gv/command_AbcPageHandler/theme_uk_hospitalcommunity_3_0

This stuff can be applied to stator teeth to prevent electrical contact between
mag wire and stator. It is available from many web vendors including LensRC.
Also great as hinge material for park flyer size planes.

UPDATE: Spoke too soon...LensRC no longer carries Blenderm. However, the
same product is sold as Du-Bro RC Electric Flyer Hinge Tape by RC vendors.
Try http://www.toddsmodels.com and look under hardware/hinges.

[mohillbilly]

James take your stator and get the thickest wire you can find and put 5 turns on it! it may not be the best but I bet you can get it to work! its a start :P

[snakeX2]

I have some surgical tape but i think it may add too much thickness. Worth a try i suppose. Well anyways i tried black-bin bags but the results were even worse. I suppose it could be my copper but the new thicker 26g i have had similar results but the less winds make it easier to avoid shorting.
I know that it is turns that govern the Kv but i need around 20t and the 26g just don't fit.

My last option is to get an odd CD-R out of my computer. I must have a cursed stator!!


J,

[jbatch]

Must be a sharp edge on the stator you're winding. Try rounding/smoothing its
edges with fine emery, then coating with lacquer or taping with very thin tape.
It's not a good idea to hack apart an old CR-ROM drive, since there are better
options, like GoBrushless products. This company pioneered DIY CDR motors and
they make it easy for you to create a motor you'll just love. (Nice people, too!)
http://www.gobrushless.com/ccp51/cgi-bin/cp-app.cgi

[mike3976]

When I first started to wind my own stators, I thought I had shorts also, but what the problem really turned out to be was poor soldering to the solid winding wire! And trying to use a older CC-25 as my test esc. I've got some stators that have some of the insulation rubbed off during winding, and they work fine! Maby look into what I have described.

[snakeX2]

Well guys, i finally got a working motor :). Took apart my 48 speed CD-R and found a similar motor. It had a small 2mm shaft and the stator was about 1.5mm less thick so i thought it couldn't sustain as much power. But i wound it with 28g, 20t anyways, put the other motors magnet/bell and the centre bearing housing and i got myself a fine motor drawing 7.5 amps WOT spining a Gunther 5x5 up to prop stalling speed.
First wind and no shorting at all.

Still i guess that other stator was just a bit sharp despite the fact i already took my dremel and round most of the corners.

Now to get me some more CD-Rs for hacking!
Thanks all for input and knowledge,


James,

[latrans]

Snake,

I have been down this road before and I have had perfect success with 5 minute epoxy. Apply a thin coat to one side of the stator, let it harden, then do the other side, let it cure, and then fill any spaces you may have missed or reapply another thin coat if needed. Let it cure for 24hrs and you're good to go. I swear this works, just don't get any between the teeth.

Latrans

[snakeX2]

Hi Latrans, that is a great idea. I bet that would provide a tough coating surely would not be penetrated.
Still, i've fancied a method that would just require the entie stator to be dipped, give it a few hours and you got a perfectly coated stator.
Thanks for sharing the idea,


James,

[ImaBiggles]

Hi Latrans, that is a great idea. I bet that would provide a tough coating surely would not be penetrated.
Still, i've fancied a method that would just require the entie stator to be dipped, give it a few hours and you got a perfectly coated stator.
Thanks for sharing the idea,


James,

I tried dipping in thinned down (with isopropanol, 99%) 30 minute epoxy. The problem was getting the darn stuff off the stator heads!! Ended up using a dremmel and diamond bit- that did the trick.

[Chippie]

latrans,
how about coating the stator teeth ends with something like petroleum jelly prior to dipping...the pj should stop the epoxy adhering to the point where you need to dremmel it off.

[latrans]

You really don't want or need to dip the whole stator. You only need to insulate the areas on the stator that are likely to cause a short (i.e. the sharp/pointy bits). Dipping the stator so that it is totally covered in epoxy will 1) thermaly insulate the stator so that it will heat up more quickly 2) add uneeded weight to your motor and 3) take up room between the arms which will reduce the amount of copper that will fit between them. Don't make a simple project a difficult one, just coat the areas where a short is likely to occur, let the epoxy cure 24hrs and you're done.

Latrans

[ImaBiggles]

You really don't want or need to dip the whole stator. You only need to insulate the areas on the stator that are likely to cause a short (i.e. the sharp/pointy bits). Dipping the stator so that it is totally covered in epoxy will 1) thermaly insulate the stator so that it will heat up more quickly 2) add uneeded weight to your motor and 3) take up room between the arms which will reduce the amount of copper that will fit between them. Don't make a simple project a difficult one, just coat the areas where a short is likely to occur, let the epoxy cure 24hrs and you're done.

Latrans

yeah but its easy :)

[latrans]

Good God it sounds like a huge PITA, epoxy between the arms, one the heads of the stator teeth, in the bearing holder tube, etc. I can do a whole stator in about 15 minutes, sounds easy to me.

Latrans

[ImaBiggles]

Good God it sounds like a huge PITA, epoxy between the arms, one the heads of the stator teeth, in the bearing holder tube, etc. I can do a whole stator in about 15 minutes, sounds easy to me.

Latrans

I hear ya, takes about 30 minutes of real work (15 mins on, 15 mins take epoxy of off heads) so it does sound more labor intensive. My eyes may not be as good as yours to paint the edges ;). However if I wanted to save labor time, I wouldnt be into this hobby.

[Roti]

When I started winding motors I found the GoBrushless "Newbie" wire very handy as it has a hard coating (polyamide I think) making it easier to get no shorts. It also comes in three colours for easy phase identification. Come to think of it I still prefer it to the other wire I've got.

Richard.

[rick121x]

When I started winding motors... GoBrushless "Newbie" wire ... hard coating (polyamide I think) making it easier to get no shorts. ...three colours for easy phase identification. ...I still prefer it to the other wire I've got. Richard. That was my experience too. Six or seven motors and no shorts... I like that record. I even bought 22 and 24 gage wire at Frys, and have had no shorts with that either.

I have been using Gobrushless stators - they are coated, and so very cheap at $1.00 or less!

I have had my biggest problems with non-concentric bearing holders causing the armature to hit the magents!

Richard (too...) :cool:

[aeronut66]

James ~ AWG and SWG are of different diameters with SWG being larger. I saw a chart in one of these threads last week giving the data. You'll struggle to fit 26 swg I think. Most of the posts from the US guys refer to AWG I suspect. I have GoBrushless 26 AWG (?) and 28 SWG + 30 SWG from Maplin in the UK ~ send me a PM and I'll mic the sizes for you.

Just wound a 32T x 30 SWG Delta terminated on a standard 22.7 mm GoBrushless setup and it turns an 8x4.3 GWS at 6500 rpm steady off a 3 cell LiPo (good for about 280 grms of thrust according to Babcock Thrust.xls spreadseet). I need to chck the current draw at the w/e but it can't be bad as there is very little heat build up in anything.

I went for the thin wire and delta to give me more room under the can. My first 2 efforts stuttered past a third throttle. Don't give up!!!

David

[Ron van Sommeren]

James ~ AWG and SWG are of different diameters with SWG being larger. I saw a chart in one of these threads last week giving the data... www.powerditto.de
-> English
-> (Tools) copperwire and magnet data

Vriendelijke groeten ;) Ron

[aeronut66]

Ron ~ thanks ~ I'll bookmark this for future reference.

David

[Ron van Sommeren]

A method for detecting short as they occur in the first message here:
http://www.rcgroups.com/forums/showthread.php?t=240993

Vriendelijke groeten ;) Ron

[BAR-STOOL]

Just Thinking
I have never wound a motor but from reading this thread I have something you people could try.
Wind the stator were the wire go's with Teflon tape you know the 1/2" wide teflon tape that you use on pipe threads. It is very thin and conforms to the shape of what ever you are puting it on. One more thing about Teflon tape it is good to about 500 degrees F
All done thinking now.

BAR-STOOL

[aeronut66]

Bar-Stool

Seems like a good idea to me :) but I'm sure I've read in one of these threads not to use Teflon but no reason given ~ can't think why as it's pretty inert :confused:

[BAR-STOOL]

Bar-Stool

Seems like a good idea to me :) but I'm sure I've read in one of these threads not to use Teflon but no reason given ~ can't think why as it's pretty inert :confused:

Can't see how it could hurt anything. Plus it mite help the wire slide around the stator when winding the first wraps.

BAR-STOOL

[Ron van Sommeren]

Alas, Teflon tape is not such a good idea, it 'flows' under pressure. Perfect for sealing a thread, not good for stators.

Do-it-yourself motor homepages, manuals/tutorials, checks and tests in the first message of this motor builders tips and tricks thread. The checks and tests may save you from frying your controller. Thread is active, bookmark it for future refence and subscribe to it:
http://www.rcgroups.com/forums/showthread.php?t=240993


Vriendelijke groeten ;) Ron
• diy motor building tips & tricks (http://www.rcgroups.com/forums/showthread.php?t=240993)
• diy outrunner discussion group (http://www.yahoogroups.com/group/lrk-torquemax)
• int. E fly-in & diy outrunner meet (http://home.hetnet.nl/~ronvans/), June 25 2006, Nijmegen, the Netherlands

[mohillbilly]

Don't use teflon tape for insulation:

Don't use teflon tape: It flows. Use mylar tape.

Cheers,

Peter Stuy

Its in the tips and tricks link above by Ron

[podavis]

Alas, Teflon tape is not such a good idea, it 'flows' under pressure. Perfect for sealing a thread, not good for stators.


I can say that this true as I tried pipe tape but got a short.

I think the hardest thing to learn is to how to apply a consistent amount of tension so the wire is tight but not too tight. I also tend to jam the wire between the last full loop and the underside of the 'T' and I know from watching the ohm meter as I unwind a shorted wire that I've gotten shorts from wedging wire into this 'crack'.

[fly_boy99]

Ron-

What do you mean by "flows"? I've used it and it works fine.

Maybe I'm just lucky but then again I used a higher guage wire with less turns for a lil speed demon.

Guess shrinkwrap can do the trick as well if you don't lose too much area.

Hmmm mylar....

[aeronut66]

Fly-Boy

If teflon is put under pressure between 2 surfaces it will extrude over time. This becomes much more pronounced as the temperature rises. Alas I've had this problem at work with valves for aircraft :( ~ wasn't sure if this was the reason when I did my last post

David

[aeronut66]

Podavis,

I've noticed the lacquer on some wire crack or shell under duress, particularly when adjusting the winding. Shows up with an eye glass if you've got one.

David

[NotAnAce]

Guys, new here and haven't done this yet so have no earned input... but how would a wrap or two of Teflon plumbers tape do in those stators for insulation?

Makes sense to my un-learned mind.

...never mind.. the Teflon "Don't use" posts didn't show until after I posted this.... It flows.. ... . .. . YES, it does.

[fly_boy99]

Makes sense alas I didn't exert much force when winding the stator I was having shorting problems on.

I'm going to give mylar a try or shrinkwrap if the stator isn't too small.

Fly-Boy

If teflon is put under pressure between 2 surfaces it will extrude over time. This becomes much more pronounced as the temperature rises. Alas I've had this problem at work with valves for aircraft :( ~ wasn't sure if this was the reason when I did my last post

David

[podavis]

I've tried a number of paints and the best I've tried so far is a 20 year old can automotive touch-up paint that matched a friend's Chevette. Paint engineered for metal only is harder than any paint that is compatible with wood. I've been trying a high temp engine paint but it's so hard that it's brittle. I had an epiphany this morning, I have a little bottle of touch-up paint, the type the dealership sells that comes with a built-in brush. A plus is that it's thick, I usually have to add a couple drops of laquer thinner before touching up paint chips on a car. I brushed on a coat on each side of a stator tonight and will give it a go in a day or two.

[podavis]

The stator with the auto touch-up paint from the little bottles sold by dealerships worked beautifully. A single coat hardened with a nice thick slippery surface. I used it to glue down the wires too, I think I've had failures caused by the insulation getting worn through because of vibration.

[t-turley]

That is excellent news. I have some of that around here, and some uninsulated stators. Thanks for the tip.

Tony Turley

[floss]

In the winding trade we use a very thin woven glass tape with of course a sticky back, if you have trouble with your winding wire "blowing" on corners of the lamination stack don't forget you can always take a tiny file and round off those sharp edges. The marine industry provides the best epoxy resins for brushing onto the stack if you don't want to use tape, they are 2-pot and with a viscosity of housepaint they can be brushed on with a small brush and provide excellent insulating properties. If brushed on after winding the chances of a turn to turn short will be greatly reduced. The good thing to is that most manufacturers do a small amount for little repairs so you don't have to buy 2 litres. Look for any 2-pot clear epoxy at your local marine store, you can usually buy thickeners too but these are definately not needed. Be aware these epoxies go rock hard and are incredibly resistant to heat, more so than most purpose built winding varnishes.