I made the MOST EXPENSIVE 2207 motor (with 100% Silver Wire) and KILLED IT 😭

Please support battery testing: patreon.com/chris_rosser
Timestamps:
0:00 Intro
0:45 The setup
1:17 Why Silver?
1:47 Unwinding the motor
3:43 Winding diagrams for a 12N14P motor
6:43 Rewinding the motor
10:35 The motors for test
12:57 Test results
14:52 Conclusions and the end of my Silver motor

[@FPVKrash]

Instead on chemically removing a more durable enamel, you could use sandpaper or emery cloth on the ends of the wires to get that enamel off as solder prep. It’s inelegant but it works.

[@SmileyFace01]

wont fire work too?

[@FPVKrash]

@@SmileyFace01 Fire sure would work. Too hard to control where the enamel stops burning off though. You would get much more precice control of where the enamel remains by sanding.

[@SmileyFace01]

@@FPVKrash Well when burning the enamel off I still like to sand it a bit.. so It's probably just an unnecessary step

[@FPVKrash]

@@SmileyFace01 Only time I’ve burned enamel off wire has been when I was rewiring a fencing foil, but it doesn’t matter if a bit more enamel comes off in that process. Having burned enamel off wire, it’s not something I’d ever try on a motor wire. Some folx sanded their wire after burning enamel, I never did and always had great conduction.

[@clockworkvanhellsing372]

​@@SmileyFace01fire may lead to oxidised metal making a bad solder connection. Sandpaper ist better, but at that wire thickness using a silicone abrasive disc from proxxon may be the easiest was.

[@kelvinlee7956]

great experiment Chris! I used to made 4 x 2207 with silver wire for Mr.Steele. I remember he told me the performance is similar to a normal copper wire motor. that's why we didn't make it to the market. it is also super expensive lol

[@robertsmith2956]

It is worth if for winding guitar pickups though. It is more sensitive, and gives you a wider range over copper.

[@computerman4321]

I lost and crashed my quad which left the ESC buzzer on for like 30mins and burnt out three of my motors. I naively thought it's just a matter of buying some cheap copper wire and rewinded all three only for the motors to smoke again! Turns out you have to get a particular type of enamel insulation that's high quality as what I noticed happening was the stator core scratched off the cheap insulation due to how sharp it was. In the end, it worked perfectly and I got my motors back but I couldn't match turns count of the original windings, just not tight enough and the KV was a bit off to the original. But it's good to know that if I ever ruin an expensive set I can get them working again

[@krautergarten4529]

Its highly recommended to press the wire straight in the slot after each half loop and not loose tension. If u don't do that u will have a little slag in each loop, so the wire will be moved by the electromagneitc forces, that rubbing will drasticly lower reliability and increase noise. And u will have a gab between the first layer and the tooth, so u can't reach the maximum possible fill rate. The heat transfere will suffer to. U can fix the slag by adding a drop low viscosity epoxy, but that is not a clean solution but will increase motor life. Epoxy easily peals of if u have to unwind it. A better fillrate with copper will alway beat silver. Copper wires are avilable in finer diameter steps so u can max out the winding space better. 😉 Most potential to increase powerdensity (lower weight per Nm) u will always find in the magnetic circuit. Hind: smaller air gap.🤫 And hand wound motor always beat machine wound because u can always squease more windings in by hand. 🖖

[@krautergarten4529]

Most important tool are broken probs. Use the prob blades to press wires to the teeth.

[@The_1ntern3t]

​@@krautergarten4529Broken props are so versatile lol. Other uses are motor wire protection and of course as a stabby tool.

[@combinacijus]

Assuming motor is designed to the limit, would smaller air gap still increase performance if the magnetic circuit is already saturated at max power?

[@krautergarten4529]

@@combinacijus The magnetic circuit should never be "staturated" in a good design, that would cause high losses ... bad efficency but high torque density in some limits. So u always have some kind of design wiggle room. Smaller air gap will give u higher flux in the air gap. Or the same flux with thinner magnets -> lower weight. These rc motors are never designed for max efficency or power, they are designed to be cheap. U will never find room for more copper in a good motor design. But u are right, u will never know which materials were used for the stator lamination or the flux return ring, so increasing the magnet grade or the thickness has some limits.

[@krautergarten4529]

@@The_1ntern3t If u need a stabby tool for ur last windings u know that the motor will rock🤘 or burn 🤪

[@mbug7973]

This was really interesting! Thanks for investing your time and money to make such a cool experiment!

[@Eleanor25589]

nice to see how much fun you have doing this stuff.

[@butterflyfpv]

Thank you Chris! Great work!

[@sylaswojciechowski6895]

How about an experiment showing the differences of a neat vs loosely wound motor? I remember flying old emax motors years ago and those windings were messy as can be.

[@taavituisk8452]

You can pack more copper into the motor when it is neatly wound.

[@adamrobertson7215]

@@taavituisk8452 Is that the intention though if you need a specific number of windings?

[@toolbaggers]

@@adamrobertson7215 For the same number of turns you are able to use larger gauge wire (more copper) or are able to make a smaller more efficient motor with less air gaps if using the same amount of copper.

[@unknownhours]

@@taavituisk8452 Due to larger air gaps, messy winding will experience lower proximity effect, and thus lower effective resistance (the coil will also be higher Q, if you care about that).

[@superduperjunde]

@@unknownhours so which effects outweigh?? Are there applications where windings are purposely made more loose?

[@KCQuadTronX]

thanks chris for a great test vid

[@sunsetpark_fpv]

Awesome job Chris. Just the fact that they spun after being hand wired was great. So many variables to deal with.... Is there a Chris Rosser signature motor in the near future? 😁

[@victoryfirst2878]

I tip my hat off to you Sir for trying silver windings. I would bet that using teflon insulation on the sliver wire would give you an honest test with very useful information. Good day Chris.

[@JoanMendoza]

Thanks for doing this! I look forward to your video on silvers properties :)

[@MCsCreations]

Fantastic testing, Chris! Really interesting indeed!!! 😃 Stay safe there with your family! 🖖😊

[@razzreal_fpv]

definitely one of the more interesting and better videos, this was cool

[@sethschneider9764]

I've been looking forward to this video since you announced it. Thank you for doing this. I have a few probably dumb questions. How would having multiple layers of winds on a stator affect the motor? I'm not sure if this affects how the motor fundamentally works and is out of the question. This would obviously be pretty difficult on a small motor like this, but you could possibly add another layer just on the outside portion of the stator. You're doing great work man keep it up!

[@rohansully584]

Nice work. Thanks for doing it!

[@Chris-oj7ro]

HAHA, YOU DID IT!! and so quickly too! I love it!

[@michi386]

Hey Cool idea to compare the different material against each other! When the motor doesn't spin up right, like your silver one did, you definitely are having a problem with either a short to the stator or a miss-wound coil. There's also a little trick for winding the AaBbCc style windings. After you completed the first two coils for phase_one, start with the second phase right after that and then the third...With this technique you only have to wind in the middle of two wound coils once!

[@butcher]

Wow maan, what an awesome content, you are brilliant :D

[@bren42069]

little motor gone to fpv heaven, where all the enamel is perfect and there's no resistance

[@silkjamfpv]

Nice video Chris!! I really want to rewind a damaged motor i have just to see if it works like a challenge and to learn more about motors. I got the copoer wire already ....so good timing for this video!

[@stanleydsouza6723]

Beautiful, valuable information and more on using silver..Thanks Brother..

[@tk-maker]

Wow, most useful and detailed info about winding a motor, i got one XING2 awaiting rewind. thanks

[@dekutree64]

I have a similarly expensive 2208 motor on my to-do list, making the stator out of mu-metal foil. Theoretically it should produce much higher magnetization for the current, allowing use of higher torque for the same resistive heating.

[@DavidOwensuk]

I admire your dedication!

[@stefanguiton]

Great video!

[@stanleydsouza6723]

We the enthusiasts the world of innovations always pray for much more and prosperity ..God bless 🙌 you buddy

[@visioneerone]

I see that the patron money be kickin in. 😃

[@BentProp_fpv]

Holy cow! I wanted to re-wind some of my burnt motors but didn't get round to actually do it. After watching your video, I finally started with one of my motors and WOW! It spins! 😳 It's even close to its original KV value! That is such a satisfying feeling! Altough it's really a lot cheaper just buying a replacement, it is definitely something, one should have done! Too bad you didn't capture what happened to your silver wound motor, there must have been a lot of smoke 😅

[@robertsmith2956]

or showed how much easier it is to wind the silver being a softer metal.

[@GrimSpeedFPV]

This was pretty awesome watching!! Thank you

[@adrasx6999]

"I didn't find rewinding the motor was that difficult" - Kinda funny how you start with this sentence and end up with all the little details which make it really fiddly, ending in the conclusion that you rather buy a new motor instead of rewiring it :) The diagram isn't very complicated, it's these little details like wire the coils nicely etc. Great job though! Now I can finally wire my own

[@zunairsajjad7098]

You are really good teacher you deserve better 👍

[@neail5466]

lovely, very much loved your experiment. coul you please tell how did you open up the motors? I don't see any circlips!!

[@gloorfpv1801]

Hey this is a really cool experiment,,, I learned something today

[@cocosloan3748]

Great video 👍👍

[@grapedrannk]

Thank you for your hard work!

[@CarbonGlassMan]

That was a LOT of work you had to do for this video. Cool test.

[@k4x4map46]

Wow!! Just changing a unibell has me sweating lol gonna need a larger motor myself great stuff!!

[@losergene7002]

Thanks Chris. Great job any very entertaining.

[@dalegifford18]

So how expensive was the "Most Expensive 2207" (Not including all of your time)?

[@jtcustomknives]

That’s not a lot of silver. Silver at between $20-$30/oz I’m guessing it’s $5 worth of silver.

[@M-H433]

Hmmm,good question,so 5.00$ is that correct?

[@RCOverKill]

​@@jtcustomknivesyea, but that doesn't include making an enamel coated wire from it.

[@M-H433]

Would actually be good to know actually how much the enamel wire is,just out of curiosity.

[@RidiFPV]

​@@jtcustomknivesplus he said sterling silver, so its not even pure

[@adrasx6999]

I don't know if it's the cheap motors which I've got, but you windings look way better than the factory ones I've seen

[@poiu477]

I just started this video, was interested by the explanation between silver and other metals, so you can imagine my elation finding out the algorithm showed me this vid 20 minutes after the other went live!!!!

[@multentlava]

looking forward to the gold wire test

[@HughCStevenson1]

You can always test a hand wound motor by driving it with a drill and measuring the back emf with a scope!

[@Gavs_rc_hobbies]

Awesome video. I have an old motor off a quad that seems to be faulty. I migjt have a go at rewinding it.

[@FINNIUSORION]

great stuff. I haven't re-wrapped a motor in over a decade at least lol. there's so many companies now making so many different types of motors it's not worth the time and effort anymore.

[@petrokemikal]

Chris you should do a video on a few of the dirt cheap aliexpress motors floating about.. Id love to see what some of them are like.. I just seen a couple of micro brushless motors there recently for like 4 bucks a pop.. Could make for the ultimate budget build..

[@iclazion]

After watching this intriguing video, I couldn't help but wonder if we could create something extraordinary. Imagine taking a long copper pipe, delicately threading silver wire inside, and then drawing the copper tube through a die to stretch and wrap the copper around the silver. The result? A fantastic foundation for winding the brushless motor. The beauty of this idea lies in having the silver securely embedded within the copper, ensuring it stays put even if it approaches its melting point. I hope this idea works :)

[@MetatronsCube23]

electricity flows over the surface of the wire not inside of it, hence the silver coated copper. It melted because there was a flaw somewhere in his winding.

[@thomasmaughan4798]

@@MetatronsCube23 "electricity flows over the surface of the wire not inside of it," Direct current flows through the entire thickness. Radio frequency energy travels mostly on the surface, how deep it penetrates depends on frequency. en.wikipedia.org/wiki/Skin_effect "At 60 Hz in copper, skin depth is about 8.5 mm"

[@benjaming9835]

I used to build my own brushless motors from old CD-ROM motors & Neodymium Magnets, because brushless hobby motor were very expensive or too big. I was very surprised to see your two winding methods! Normally I'd wind each station the same direction and then each other station would be another phase in turn, so the same phase is never next to itself. This is easier to keep track of what's next to wind, I never did mark up the stations, (but good idea). It's good to use different coloured wire for each phase too. btw you burned out a motor, can't be sure of course but if you make mistakes in the windings this will lead to coil miss matches that always end in burning out the motor.

[@adrasx6999]

To get rid of the enamel you can also use sandpaper, or burn it off with a torch. No need for nasty chemicals. I could also imagine that acetone could be used to dissolve the enamel

[@ProximoFPV]

Hey Chris, is it possible you make a video about how to make your 5inch race quads lighter? I've been thinking of ways to cut weight and was wondering if you have any ideas I have not discovered yet. I've seen a few pictures of MCK quads being insanely light with some secret motors? Not sure exactly whats going on there but Im super curious if you have any insights.

[@ColinWatters]

If the number of turns is the same I would expect the Kv and RPM should be fairly similar. Silver has a slightly lower resistance than copper so there should be a very slight improvement in efficiency of a few % as you found. This might be worth it for some competition classes? One issue is the diameter of the wire... a very small change in diameter due to manufacturing tollerance can have an effect on the cross sectional area and resistance.

[@justfly7730]

You killed it with that video. 😅

[@BrightBlueJim]

Did I mis-hear, or was the silver motor erratic even on the initial unloaded spin test? I think it had a shorted somewhere from the start.

[@hanswerner6882]

interresting video subed!

[@Prince_3530]

a great experiment i literally searched this thing many times about 2-3 years ago but didn't found any answer about this . you did a great job but remember your mistake was silver is more conductive hence it will need more turns on each and every pole of the motor then previously wound copper coil . and can you do this again with more turns of silver wire or you can just use thinner silver wire so that we can see that science in a practical way . thanks for this video.

[@guytech7310]

You can try different winding wire formats, such as litz wire & flat wire. I am not sure what the switching speed of the motor coils are, the skin effect can reduce current flow. Probably with flat wire you can increase motor torque.

[@multimargejta123]

Where can I buy enamelled silver wire?

[@dfgaJK]

If winding silver wire why not use the twisted pairs to go to the esc rather than soldering ti copper silicone coated wire?

[@FPVKrash]

Good point. If you’re winding your own motors, why not keep it super clean and not add unnecessary joints. That could end up as a super-sick build but personally, I wouldn’t be able to handle it if I clipped a wire too short when soldering to the ESC. 😅

[@dfgaJK]

@@FPVKrash Imagine, and you know it is going to be the last wire of the last motor that's too short! And the agony deciding between an ugly little extension or rewinding the motor 🤣

[@Inertia888]

@@dfgaJK 😂Stop. Put it on the shelf. Forget about it, and start building an entirely new quad. Get board, and pull it off the shelf, to get winding again.

[@EugeneWangombe]

Where did you purchase the silver wire from?

[@johndeesfpv9289]

cool video thanks

[@conorstewart2214]

You can just sand off the enamel coating too so you don’t need the solderable wire. Or if it needs a higher temp to burn it off then maybe a lighter or mini blowtorch would work

[@williamfraser]

Just wondering about the switching frequency and possible skin effect. If frequency is high enough for skin effect to become a problem, the silver plating on the copper wire would be conducting a higher proportion of the total charge.

[@HolmesHobbies]

In the coils it's just the commutation frequency, as the inductance smooths pwm frequency to be almost nil. So skin effect in this size of motor inside the coils is not really a factor.

[@jsalsman]

In my friend's lab where they use silver coils for micromotors powering biofluidics, they insulate with ceramic instead of enamel or epoxy. I don't think it's for heat, though.

[@bobwatkins1760]

I don't know how England does windings but here in USA we use a poly coated paper in between the stator spaces to assure when we wind or rewind a motor stator there is almost no possibility of short due to sharp edges on the stator area. I was thinking when You were doing that winding that You'll probably get a short.

[@danspratt2]

interesting stuff dude! Do you think you could change your mic settings to lose the lip smacking sounds? I dont know if its just me that finds it hard to listen to (12:57-13.01 as an example)

[@modquad18]

Ugh, why did I have to see your comment. Now that’s all I hear 😫

[@GinTonicFPV]

Hi Chris, do you think we may see axial flux motors for miniquads in the future?

[@marc_frank]

that would be cool i've been thinking about how the stator laminations could be simplified for such a motor, but haven't found a solution that's one of the problems that have to be solved before they are introduced

[@billmcdonald4335]

Next week: Chris tries winding a motor with Cavorite wire. . . provided the dilithium kididdle meshes with the grapple grommet. Wizard.

[@marc_frank]

you can also make 1,4,7,10 one phase then 2,5,8,11 and 3,6,9,12 (for the star configuration) i wonder if connecting a ground wire to the star point would reduce electrical noise

[@PiDsPagePrototypes]

Probably do the opposite, and give the AC 'noise' a direct path in to the DC circuitry.

[@robertrosicrucion]

cool video. Would love to see you go long on some deep dives!

[@laurentbeaulieu2446]

Is that wire also available in gold?

[@williamgambill3922]

silver plate copper works just as well as solid silver with the exception solid silver may run a lil cooler. electricity travels on the outsides of the strands not the center.the differences in winding patterns (how tight and neat)is the biggest problem to keep the test fair. but if two Motors were wound identical one with silver-plated copper and one with just copper there will be a 5 or so percent performance difference in efficiency torque and RPM

[@cch201992]

I like to see people try stuff even if it's expensive because that tech could change the world and would lead to more people working on bringing cost down of the raw materials I like to see what is the best ultimate version of anything I hate when cost was the limiting factor of a design

[@anunnakielohim2727]

Any idea if a braided wire wound motor would be better than a solid wire wound motor?

[@colinjohnson5515]

Solid is better. I think it has to do with higher cross sectional copper density. You want as little air gap between each winding to increase flux density so I assume the air gap in multi strand wire would lower that density. Braided/multi strand wire also has higher resistance which lowers your efficiency.

[@Aar0n2009]

Is it possible to do CCA next?

[@deltapag5051]

Do you have a price comparison of copper, silver plate & solid silver magnet wire? It seems that silver plate is the way to go.

[@jakub9916]

Will you make 7" motor test?

[@annoying_pyro_]

@Chris Rosser Thanks for great educational content. I have a question about motor RPM. As you explained in motor KV video, the motor RPM is limited thanks to back EMF, which is negative voltage that prevents the main voltage from creating a current draw. But what actually prevents us from just applying more voltage to the motor to exceed back EMF and get even more RPM, assuming the power supply/ESC can handle it and motor is free spinning (or, more strictly, the useful power is small enough so that the actual current draw for the voltage applied is below some point where the motor starts to melt)? And if that's actually the way then what is a point of motor's voltage rating aside from just being a recommendation for typical usage in drones? (I suppose this should have been asked under the motor KV video, but now it feels more likely to get some attention here.)

[@thomasmaughan4798]

"But what actually prevents us from just applying more voltage to the motor to exceed back EMF and get even more RPM," Nothing at all prevents it. The KV rating is the RPM *per volt* so if you double the voltage you double the RPM. at some point the motor will self destruct.

[@annoying_pyro_]

Thank you for your answer. I wonder then what the motor voltage rating is intended to mean.

[@yowild9629]

dealing with system losses can improve eficency using switching mechanism that is Reactive to watage instead of current

[@barabolak]

You have to try again and compare the output of solid silver vs silver plated.

[@HughCStevenson1]

Precision DC resistance measurement of the coils would be interesting

[@nickoutram6939]

I would like to see the same experiment but using some of the new Fujitsu 'K107' room temperature superconducting filament.

[@williambrasky3891]

You can use sandpaper to strip enamel off the ends of the wires.

[@DibutilFtalat]

Try Litz wire and compare! It should work better than silver, the conductivity is the minor factor compared to inductive resistance.

[@conorstewart2214]

Technically I think you could wind all coils with a single piece of wire. Wind one phase, leave a loop or tail hanging out then move onto the next phase. Since all phases are electrically connected it should be possible.

[@mark6302]

thats intense

[@TheOriginalEviltech]

Can you try winding a motor with Litz wire? I would love to see how it performs in a motor!

[@luclachapelle3499]

Well done ! You should also compare using Litz wires All tests should be done using the same current

[@simontillson482]

Litz wire is not going to improve anything - the frequencies at which it would make sense are in the megahertz range, and motors work in the low kilohertz at most. The skin effect is almost absent at this frequency, so even using silver plated copper is dubiously advantageous at motor speeds. Eg. Maximum fpv motor speeds are around 30000 rpm, which is only 500 Hz. Skin effect only starts to become significant at 10000 Hz.

[@koolaidsrequiem9646]

Couldn’t you use a fly bobbin to help in winding the wire, I don’t know if it would work but just a suggestion. It would keep your hand from cramping and maybe speed up the process.

[@tanmaymondal69]

amazing

[@guerrillaradio9953]

It might not be your handiwork that failed on the pure silver motor. It could be that due to the decreased resistance, for the same load, voltage, and PWM duty cycle was all the change needed to push the current draw into the danger zone.

[@memejeff]

Very interesting.

[@Athiril]

Theres actually a wire with lower resistance than silver, I've forgotten what it was but it was some kind of doped material

[@ah4quadssake885]

Have you tried comparing motors in a "wye" or "delta" configuration ? Huge differences in output power 🤷‍♂

[@Fleche_FPV]

Cool ! You will try again ???

[@sgodsellify]

You need to make wire that is also laced with Holmium as well as Silver. Holmium has the highest magnetic moment, and combined with the 5% less resistance that Silver brings to the table, then overall a motor that is wound with a wire that is Silver/Holmium, then that motor should use 30% less energy to produce the same results from a copper wired wound motor.

[@JohnDlugosz]

My immediate question is: how does the conductivity (low resistance) of *sterling* silver alloy (92.5% silver) compare with atomically pure silver. The Title of the video says "100%" which is wrong.

[@ssnerd583]

indeed.....925 isnt pure silver

[@elijah4666]

the dust wasn't graphite was it?

[@Plur307]

T motor makes motors with silver windings. I believe older models of the F40 pro had silver wire.

[@1kreature]

One little mistake: You did not test all 3 bells on all 3 motors. The magnets will vary a bit in strength and alignment and the 2% variation can easily come from that. Measuring the motor Ri would have been very nice as one can then easily calculate the efficiency curves.