Why Cutting Brushless Motor Wires can Destroy your Motor (Or even ESC)

You may want to cut your brushless motor wires back to either save some wiring room or just to benefit from the performance gain. Either way, before you do so, you must know if its safe.
In fact, cutting the wires on your brushless motor could turn your motor in to a paper weight if you can't undo the damage.
Many brushless motor have the winding termination actually completed outside of the motor. If you were to cut the wires, you would effectively remove this termination point. Should this go unrealized, the next time you run power to the motor, you can ultimately destroy the ESC through short circuits created in the winding.
However, if the termination of the windings is performed inside the motor, then cutting the motor wires is safe.
To ensure you may be able to cut the motor wires located on your motor, it is recommended that you contact the manufacturer.

[@chrisstoddart8376]

I had no idea this was a thing! Added to the list of handy RC stuff I've learned from you. Thank you!

[@RCexplained]

Glad to help, thanks for the awesome comment!

[@bramnelissen9106]

I think 1 rule is easy: If the motor has soldering points, where the wires are connected to the engine, then you are sure the termination points are inside the can, and thereby you can cut the wires.

[@RCexplained]

Absolutely. Very good point!

[@GT-po6by]

I've always wondered why people call electric motors engines?

[@joshuajkoplin]

Combustion=Engine Electric=Motor

[@iShootFast]

Man I learn so much from this channel.

[@baxrok2.]

Great information! Since I only run cars, I don't have this concern. However, I can see how this can be a tricky situation for those who use these types of motors.

[@RCexplained]

Thank you for the comment! If you can avoid cutting motor wires that's best!

[@ynzeselders4184]

there are rc cars that use motors that are terminated at the bullet connector. the slash 4x4 vxl for example.

[@2XRC]

Great vid! Was going to cut wire on my Arrma motor. Will definitely research more. Zip ties work too. 😁

[@RCexplained]

Thanks for the comment Randy. Zip ties work well. I bought a used motor that had cut wires. I realized when I wanted to switch the motor in to another RC that the wires were not long enough to reach the ESC by about 25mm or 1 inch. I had to change plans to make it work.

[@ramadavince6611]

I've shortened motor wires without problems, from what I understand the wires are sometimes tinned back to the motor and some are enameled, as long as you scrape of the coating before you solder it should be fine... I've done this with a 450 and an mcpx bl.

[@richardhayes2514]

Very informative and interesting. Thanks.

[@RCexplained]

Glad it's helpful. Thanks for the comment Richard.

[@Chris558576]

Thanks for this, i never knew this was a thing.

[@RCexplained]

Glad it helps

[@79Blazer]

Thank you! Very helpful

[@dnml4713]

Love it, great info. Would help if we could zoom in on the two types of motors. Don't think I'd know what they actually look like. Looks like you have them in hand, anyway!

[@RCexplained]

Great suggestion! Thanks for the comment dnml471!

[@MRPCB-qb2ge]

I wind my own motors, as long as you make sure you re-terminate all the windings, It's perfectly safe and easy to do. Often times these motors are wound with solder through insulation/ lacquer. If not just burn off the lacquer. This video should have focused on how to do this safely instead of just trying to frighten your viewers into avoiding this procedure.

[@bashaz8559]

Thanks for all your vids man they're really educational. I've installed a 5694 sss motor into an oc8s and needed extensions as the original wires are only 8 cm long. I've gone with 8mm bullets and everything was perfect but after a few rides the car started cogging, only on Immediate FULL throttle. I'm suspecting the extensions which are made of 8awg silicon coated wires. Is it advisable to solder the 8awg onto the original ?8filament copper motor wires or is it better to get a same diameter copper wire to extend them? I've been thinking to replace the whole wire but I'd need silver solder and more than my 80w solder for that, IF termination allows that is, haven't opened the can. Thanks for your help!

[@perre___]

Hi, where are you buy the extension?

[@diemturner5755]

What about saddling the horse from the other side...are the similar issues if you were to lengthen the motor leads?

[@ejonesss]

1. unless you are being judged by the assembly neatness you should have room between the body shell and car platform in witch to fold the wires up into. 2. cutting into the windings could effect the inductance and may cause performance and even current draw issues. 3. some motors are big enough to have solder points or plugs on the back for a delta or y configuration. some of the bigger boat motors will have 6 connections in witch you can configure y or delta.

[@StevenYDG69]

If one of my bullets has 1 prong broken out of the male connector, is it safe to run?

[@andyroo8uk685]

brill video ....i have a 1/14th car and brought a 60amp hobbywing esc and the wires are as long as the car can these be cut down if so how much

[@RCexplained]

You can cut down the ESC's 3 motor leads as far as you require.

[@ddegn]

It would have been really nice to show some examples of termination types.

[@RCexplained]

Here is a video: kzbin.info/www/bejne/f5rSoKeHqcd5a5Y

[@SpeedSyko]

Ouch, I do this all the time! I only had a problem with a traxxas vxl motor. I cit it right at the bullets to fit a different size. Now it overheats fast. It was tarnished so I’m going to try and reduce it and try again. Not smart. I was in a hurry. Or I ruined the termination. I’ll get ride of the enamel at the termination point. Worth a shot. Thanks buddy. 👍

[@DoRC]

This doesn't make any sense to me. The wires that lead to the termination point are going to be separated out by the insulator in which they reside. No matter how short you cut the wires as long as they still reside in the same insulator there's still terminated the same. Maybe I'm missing something

[@RCexplained]

Motor wires are copper with an enamel coating, look inside the motor and you will see these. Multiple wires of this nature could be beneath the wire insulation that you see coming out of the motor leading to the connector. The winding termination in some motors (less these days) can be at the connector.

[@DoRC]

@@RCexplained Yeah I get that. What I don't understand is why removing that connector shortening all of the wire that's inside the insulator then removing the enamel insulation re-terminating and putting a new connector on would make any difference. You're not actually changing the orientation of any of the connection you're just moving the connector along the entirety of all the wires within that insulator. In order to actually cause a problem you would have to pull the strands of magnet wire out of the insulators, rearrange them and stuff them back into the insulators in a different configuration otherwise electrically nothing is changing

[@Caseytheradioguy]

Thanks sooo uch for this

[@RCexplained]

No problem! Thanks for the comment Casey!

[@nts323]

Do you know how to repair damage motor wires.

[@Siphonife]

My Dad is building a drone and I'm building my first plane just waiting on parts. My Dad without any of this knowledge has small multirotor motors he said soldered just fine after cutting. Tining was easy and throttles just fine after completion. Which leaves me wondering do some manufactures leave off the coating when the wire leaves the motor and perhaps more motors no matter the size are terminated internally than not. I'm still very new into all of this and just doing as much research as I can while I wait on my parts. I'm building a 3D printed twin prop and I'm 99% sure I won't need to cut any motor wires anyways. 31.4 in. wing span. It's going to be very challenging.

[@RCexplained]

Hi Siphonlife, I'm not entirely sure which way most manufactures go. I know that I have 3 motors and only the one in front of me has an internal termination. All 3 are out runners. In general I do everything possible to avoid cutting the wires.

[@drevilatwork]

Can you please tell me what model is the biggest motor you hold in your hand in this video at 1m 25s ? I have a hard time find double shaft brushless motors...

[@RCexplained]

turnigy sk3 series. The green motor makes more power.

[@kitchenbriks3685]

How about replacing the bullets on a castle motor without cutting the wires? I want to use a castle motor that has 6.5mm bullets but the hobbywong esc only has 4mm bullet sockets. Would desoldering and replacing the bullets make any difference?

[@RCexplained]

Castle motor is fine. You can swap connectors

[@rogerbeam3364]

Would it be safe too cut about a 1/2 inch off the brushless motor wires the solder the connectors on ?

[@RCexplained]

Hey Roger this really depends on your specific Brushless Motor. If winds are terminated in the last half inch, then you could be cutting right where a termination point is.

[@furiouswolf777voodoo4]

When you add wire to motor will this cause power loss. If I solder wire to wire will will solder add resistance? Thanks

[@RCexplained]

Any addition you make to the circuit, (series connection) will add resistance. The real question is how much resistance are you adding? What is the length of wire to be added, quality of solder used and the quality of the soldered joint?

[@xnoreq]

A very simple rule of thumb is that solder has about 5x the resistance of pure copper. That sounds much but doesn't really matter if you solder the two wires properly as the distance between the strands of the wire will be tiny. Think of it this way: if you bridge a 1mm gap with solder at the same thickness as your wire then this would be similar to just having 5mm added wire.

[@thomaswalton9089]

My esc wires got hit by the spur gear the wire that goes from esc to the battery still runs fine just covered it with eletric tape but i ordered some 10 gauge silicone wire 200c and was going to try to replace the wire but i wasnt sure if i should or not whats your opinion? My esc it the blx 185

[@RCexplained]

If you'd rather not replace the wire see if you can solder cut stands where the gear hit it. Then use heat shrink over this section, not tape.

[@thomaswalton9089]

@@RCexplained what our cut stands? This would be my first soldering project I did buy a kit came with a bunch of stuff been watching videos how to solder but have not heard of those yet

[@RCexplained]

@thomaswalton9089 the wire is not solid it is stranded. Many thin pieces of wire make up one motor wire. Is the wire cut,?

[@AJ-js1yw]

on the flip side: is it always safe to cut esc wire shorter?

[@RCexplained]

Yes, I'd prefer to cut or extend the ESC to motor wire's if I must and have no other options available to me.

[@AJ-js1yw]

@@RCexplained thanks!!!

[@SpeedSyko]

Hmm I cut my 800 kv with an XLX2 without issues. I’m sure some may not be able to cut.

[@diemturner5755]

After watching this video one might get the idea that castle creation motors are terminated within the motor housing which would mean that cutting the wires is not an issue. Or what did you think the green motor was that he was talking about?

[@SpeedSyko]

@@diemturner5755 I have no issues with castle and hobby wing. Only traxxas. I’ll clean off the enamel and try again.

[@furiouswolf777voodoo4]

Will a bad ESC fry a brushless motor? I noticed my fan wasn't working on my MM2. I ran my Typhon for about 4 min...Poseidon 2200kv died temp was 203 locked up tight. I was checking my steering for a few minutes then drove it down the street . GPS 59 mph, gear 19/50 has run over 70. I'm shocked motor blew cool day 70s esc temp was 130 IAM asking because I don't want to blow another motor...Thanks retired adult owned and baby this setup

[@RCexplained]

Hey FuriousWolf, what was wrong with the ESC? It is a lot more common that a bad motor takes out the ESC vs the other way around.

[@furiouswolf777voodoo4]

@@RCexplained ESC fan stopped working.Its a Castle mamba monster 2. I'm using 2 100c 8000mah batt in series. Motor temp 203 was very high for a few minutes of running.Geared 19/50.... I have run 40 minutes hard and temp is only 120 to 130. Esc ground connector 8mm was burned also...Hope this helps Thanks!🤔

[@RCexplained]

Hey FuriousWolf, if it's just a fan that quit that's not too serious. The motor temp of 203 does sound very high, that is concerning. Is the 120 to 130 on the motor on a typical run? How was the connector burned? 8mm is huge and can handle over 150A continuous. Do you have a data log of each run?

[@furiouswolf777voodoo4]

@@RCexplained amass 8mm connector the tip burned ground side. Need to replace ... Positive connector looks like new. When I turned the ESC on I noticed the fan was off hmmm I thought then checked steering worked fine. Put car down and ran it and it felt normal except car pulling to the left. I roll down the street adjusting trim maybe 1/4 throttle this took a few minutes. Ran it up to 60 mph then it locked up. 203 temp??? How why? Not a speed run car just my when bored car something to do lol New motor on the way I was checking with you to see if I should order a new Esc? I have a 30mm fan yeah racing I can mount on the mm2. Whatever you feel is best. I love your chan! Your tips help alot. My limitless hit 89.8 the other day thanks to your tips it's a easy 100+ car sooo Thank you so much!!!!! Sorry little long lol

[@RCexplained]

There is nothing apparent that leads me to believe the ESC is a problem. You will want to monitor your setup very carefully next run. Use very short time intervals to check temperature. Don't run the body so that you can check temperatures very frequently. It sounds like the motor was the problem, but you will have to confirm this on your next run with the new motor. Monitor heat on battery, esc and motor.

[@karenowen2242]

Can I cut the wire on my castle 7700kv

[@RCexplained]

I have not owned that motor and can't be sure. Can you avoid cutting the wires?

[@wally6629]

ALWAY PREMIUM INFORMATION on this channel.! I have a motor that has Blue/Yellow/Red leads coming from it which match the colors found on the ESC, and I also have the same Motor that jus has 3 BLACK wire, these are both the same motors, how do I determine which wire goes where on the ESC... sense there all Black? Thanks

[@RCexplained]

If it is not a sensored motor, it will not matter.

[@luigibellantoni6828]

I just let out the magical smoke from a brushless motor from cutting the wires.

[@RCexplained]

Oh no! That's not good!

[@MrsRabbit8]

Hello, do you have any videos on brushed motors. I have a separate smaller motor that i need to run along with my main motor, both with the throttle. Can I just run some smaller gauge wires back to the smaller motor? The esc has plenty of power. Please pardon the off topic question. Thank you for your vids! Great info. I havent dabbled in brushless though.

[@RCexplained]

I don't have any videos on Brushed motors. Quite frankly, I haven't used them in a very long time. Is your main motor and separate smaller motor both brushed? Are both motors ok to run at the battery source voltage? Is the ESC also brushed? What is each motor driving?

[@MrsRabbit8]

@@RCexplained awesome! Thank you for the response, much appreciated. So the tow truck is an scx24 that i dropped a wpl all metal 2 speed transmission into. (370 brushed) The trailer is a micro Barrage frame, with aluminum & balsa flat bed built ontop. Flipped around so that front tires are in back, and able to turn with tow truck tires (i got a servo reverser). The motor is the stock micro Barrage motor, most call it a 180, but actually i think it's a 050. The esc is the Hobbywing 1080 Quikrun. Usually used for 1/12 to 1/10 sized trucks... so LOTS of power, and awesome programmability, and control.

[@MrsRabbit8]

@@RCexplained both motors are brushed.

[@ddegn]

Brushed motors aren't nearly and finicky as brushed motors. The main danger in your proposed setup is burning out the smaller motor. You're probably better off using a separate (lower power) ESC for the smaller motor. You can use a Y-harness to connect both ESCs to one signal line.

[@MrsRabbit8]

@@ddegn thank you for the info. I ended up going with the same motors. I haven't purchased my esc yet, but was planning on purchasing the Holmes Hobbies torquemaster br mini dual motor esc. When going through the building plans, I realized that the rpm and gearing ratios would have been different with the different sized motors, and so that would have some issues. Probably other issues too. But I had another question: Will the volts be different after traveling through up to 16" of wire to get to the other motor, as opposed to the 4 inches...? And if so, then how much difference will cause similar issues as before? Maybe I need two esc, one for each motor, with a Y splitter to go to one RX, as you said. Maybe there are also other considerations.

[@tvon4966]

Cut my wires too short and sat there with a wire brush for 20 minutes scraping it down so I could solder it 😐

[@RCexplained]

It happens!

[@alwaysflying6540]

I cut wires on a helicopter motor years back and couldn't solder the bullets back on. They just wouldn't take to solder. Nothing that myself or friends with years of soldering experience could fix properly. I never cut wires again

[@RCexplained]

Oh wow, what happened with the motor?

[@xnoreq]

Did you remove the enamel?

[@ddegn]

Big wires can be really hard to solder. You need a very powerful soldering iron. Often times flux will help. I wrap the wires in a wet paper towel to protect electronics on the other end of the wire. I've soldered big thick wires many times but I almost always hate the experience.

[@alwaysflying6540]

@@ddegn I think you might be confused big wires are easy to solder but it's the motor wires that come directly off the motor have some sort of a coating on the wire strands that makes them extremely hard to take to solder if cut short. I highly recommend not cutting motor wires. I've soldered 8 and 10 gauge with no issues. For the most part you are right. In some helicopters you are extremely tight for space and at times you want to make the wiring as short and clean looking as possible.

[@ramadavince6611]

I have to 😂😂😂 so hard on this one.

[@RCexplained]

If you have no other choice, just make sure you are not harming the motor by doing so.

[@ramadavince6611]

@@RCexplained I cut most of my motor wire. Also I usually wind them myself, so I can cut anywhere I like if I make sure cutting after the winding part is over. (If I Don't cut them wire in the winding wire)

[@ramadavince6611]

@@RCexplained i im not harmimg my motor. insted im miproving it, i see no reason on how,why my motor should get bad coz of wire cut

[@ramadavince6611]

@@RCexplained I've shortened motor wires without problems, from what I understand the wires are sometimes tinned back to the motor and some are enameled, as long as you scrape of the coating before you solder it should be fine... I've done this with a 450 and an mcpx bl

[@ramadavince6611]

@@RCexplained see no one has a problem only you and your fellow noob had problem!!.

[@ramadavince6611]

I have to laugh on this one once again🤣😂 May be I'll come back to 🤣😂. In future 😃😂

[@diemturner5755]

You're a bit of a tit, aren't you.

[@ramadavince6611]

it clear why you has very less subcriber