How to Rewind a Brushless Motor for More Torque
ฝัง
- เผยแพร่เมื่อ 14 ธ.ค. 2017
- Here is a video tutorial on how to get more torque out of a brushless outrunner motor by converting from a delta to wye phase termination. This will get you ~1.7 times more torque but 1.7 times less rpm. This tutorial should be applicable to most hobby outrunner motors. See links below for ones I recommend! The trickiest part is removing the stator from the housing. If people find it very difficult, comment and I will post another video on how to fully disassemble the motor. Thanks and enjoy!!
Here are some links for High Torque Brushless Motors and corresponding ESCs that I have used for my projects:
Turnigy SK3 5055 280Kv: amzn.to/3vDQK9c
Turnigy SK3 6364 245Kv: amzn.to/2ZnW05b
Turnigy SK3 6374 192Kv: amzn.to/3Ean72d
Flipsky 6374 140Kv: amzn.to/3EfptNE
Flipsky 50A ESC: amzn.to/30Na7kK
Generic 60A ESC: amzn.to/3pyBdXa - วิทยาศาสตร์และเทคโนโลยี
Thanks, I have been looking all over to find the differences in Delta and Y configurations, repurposing a 3 phase motor for use in a dirt bike build ...
Been trying to do the same. I wanna get more torque out of my 750w fatbike.
"Let's send it" I love it, great video
wow from Colombia i apreciate your help and going yo try with my e byke motor thank you
how did it go?
Wow....mind blowing and very useful content.
It's just changing the kV by √3.
So either you are going up in kV by √3 or down by √3.
No real magic to this.
If you really want to improve the motor you need to actually rewind it carefully and increase the copper fill percentage.
Most motors have a copper fill of about 60%.
70% is possible with hand rewinding.
80% is nearly impossible... but if you are good sometimes you can pull it off.
Yes, to achieve better efficiency rewinding is required to fill the gap and prevent losses.
Eric is correct, this works and is common practice. Before the days of power electronics, induction motors would commonly be started in Wye and run in Delta.
When you wind a motor Delta the winding voltage becomes the line voltage and the winding current is 1/sqrt(3) the line current. Wye is opposite, the winding voltage is 1/sqrt(3) line voltage the winding current is the line current. This is intuitively correct just looking at the diagram.
Electric motors are simple animals, the more current through the winding, the more torque. Voltage needs to increase to increase speed (counter back emf).
Be careful with this one though, the winding will be carrying sqrt(3) times the current they where designed for. Resistance losses and heating will increase by the square of the current (I^2/R).
The heat generated in the motor could raise by a factor of 3!
I did the C5045 KV900 brushless motor rewinding around 3 years ago and i did´nt take care of electrical measurements but i noticed that the nominal temperature increased fast ...... Brock Kocyan you are right and it's a big miss because the changed was made to use de BLDC as a CNC spindle, the motor stays many time turned on an overheat in around 15 minutes.
For you to increase torque and lower rpms you need smaller gauge wire and way more wraps. You pretty much added resistance to current path
Great lesson, even the sound is different
There's nothing great about it, because he's completely wrong. The torque drops by the same factor as the amps. The two setups will be capable of delivering the same total wattage, but one does it running high current and lov voltage, while the other does it running high voltage and low current. And seeing that current is torque, well, there you go.
Great idea! Thats what we need more torque generating motors. Frequency driven if that helps on startup.
Run a larger prop.
speed raser you may think I'm stupid for making this comment but I actually prefer brushed motors if something goes wrong it is so easy to rebuild them you can rewind to get just about whatever you want more torque more RPM Anyway You Want It more torque used bigger wire but shorter windings when we race slot cars we used to experiment all the time with the windings on these little Motors but of course we did fry a lot of them but when that happened you just unwind the copper add a bigger gauge wire or a little bit more of the same gauge
Hi, unfortunately you are wrong. In wye connection you are using less voltage on each windings, what equals in less power, and so on also torque. Delta connection is more common because of that it give the motor more power, and more torque than wye connection, but also it causes in more current flowing through windings. If you want confirmation of my words, there is simple way, just look at power of motor in 5:17 and then in 10:31 when you changed connections to wye. It's exactly √3 times less than it was at the beggining with delta connection.
for torque only the current really matters - and at no load the power reading is pretty meaningless. Wye windings are commonly used to increase torque and decrease the rpm.
yes ，correct
That's a nice result! Do you have some sources you used know the process of rewiring to wye? I'm now thinking of doing this on a 5065 140kv racerstar for use on an e-bike i'm building. The shady chinese 48V controller I bought actually works on this motor, but I found out that it's probably not very suited for higher RPMs so this would be a good solution. Also any reduction I can get in motor RPM is useful to get to a usable RPM on the bike's big wheels.
Thanks for your video efforts, but at 5:37 you state this is a 14 pole motor, and I assume that info is used when using a factor of 7 to calculate actual RPM from Electrical RPM.
At 09:30 you show an image of a stator complete with windings, there are 12 poles not 14 poles visible in the image.
Can you confirm that is an image of the same motor being tested, or was the motor under test 14 poles?😉
So these BLDC motors are basically just 3 phase AC motors with some variable frequency circuits and use magnets instead of induction.
The Q, yes. And they use hall effect sensors instead of pre-determined frequency.
@@abrarborno2629 Only some use halls, these ones do not. Sensorless motors use back emf (noise from the phase wires) for the esc to figure out where to put power next
The Q that's the way I see it when I got my first brushless motor I noticed there was three wires and changing two of them would change the rotation and being an electrician that told me hey this has to be three phase and it is a c I can't remember if the ESC is where it changes to DC are not
@@popwall4297 The ESC also functions as the invertar.
I like your video, great way of pointing out on how to find common Nth on a stater. Grab your fancy calculator let's go over a 3-phase wire circuit. A> is red 1 B>is green 2 and C>is blue 3 that = D> Delta
So let's take Delta and Wye = what? 3 to 2 ratio. That's all we can play with🤣
With your fancy calculator let's run some numbers.
A,B,C = D Delta that is (red wire) 1 face.
+
E,F,G= H Hotel that is (green wire) 2 face.
+
I,J,K= L Lima that is (blue wire) 3 face.
Mathematically I think I figured it out. Na+Sa=A Nb+Sb=B and Nc+Sc=C ×9
Kv.... 0.5 at the most 🤷♂️
*Voltnator gobel TM*
If you had enough space in the stator, you could rewind the stator in a distributed pattern instead of the concentrated windings, the efficiency would increase.
I only have a very loose grasp of 3 phase power. Have you done any testing to see if the change had any effect on efficiency? If I understand the configuration correctly the phase to phase resistance should be about tripled when changing from delta to wye configuration. Is that right?
What do I need to do to my 83100 brushless motor to maintain up to 250 amps? Im using it for a watercraft project.
If you reduce the number of winds and increase their cross sectional area proportionally you can get more amps into the motor with the same amount of heat generated. This also increases the Kv proportionately and therefore also reduces the torque per amp. Ultimately, it just means that the motor becomes optimized for a lower voltage/higher current.
If you want more actual power, you can very carefully rewind the motor to fit more copper in the stator, this will reduce the amount of electrical resistance for a given number of winds in the motor and allow you to run more amps through it.
Another thing you can do is (if you have some gear reduction) run more reduction and a proportionately higher KV motor. You do end up running into mechanical inefficiency at high speed (bearings and gears don't tend to like 10s of thousands of RPM). Everything has tradeoffs.
By the way, those esc's are open source customizable esc'c called vesc's
Can you please shot how to do this with a Hoverboard / balanceboard Motor??? Thks
The increased torque gives greater lift, right? I mean with regards quadcopters or drones right? That is a fascinating manipulation of electrical engineering. Genius.
torque goes up, rpm goes down, power (product of both) stays the same
can rewind wye and still keep the rpm of the old delta coil or not?
of course it reduces RPM as you are increasing resistance /inductance of the circuit by setting coils in series. If you apply a voltage 24 * V3 = 41.57 you should get the same rpm as the original motor.
I am expecting no problems with insulation given that this voltage is still pretty low.
But i don't see how this can increase torque? ( i actually think this is wrong) i would expect torque to decrease at startup specifically since you are applying the same voltage, but divided over two coils....
Hence drawing less current, and generating less torque for the same voltage.
yes ， you are right
If he is changing from delta to wye effectively lowering the kv, the torque constant kt = 60/(2×3.14×kv) would be increased yielding more torque for a given line current. I don't claim to be an expert but would this not apply?
OMG.. i need to know this before i made my failed dc generator... 🤦🏻♂️
To make a DC generatorr. this does not work for you. you have to make specific calculations of the necessary Kv. and then you must get or rewind your motor for it. It does not matter if it is in Delta or star. Since the termination does not make a brushless motor better or worse. To be clearer: Two equal motors, with the same percentage of copper packing, and with the same Kv will be the same regardless of the termination they have. Delta or star.
Good work Eric.. pls give me info about winding patern because you didnt explain about it, also about wire it self are you twist four wire became one wire for winding in stator?! If there is no objection from you, pls give info about the diffrent between delta winding patern and WYE patern (in practice not in diagram).
Thanks Eric
I am rocky here and I wonder if I got it right.
I am to rewire my e bike hub motor. I can expect it in delta.
If I wire it for "Y", it will pick up less voltage, will be slower on the even ground, but will be more of a help on a steep hill ?
Anybody can confirm it, please.
What we are looking for is a motor that generates the most torque for electricity used. Even if that means supplimenting it with capacitors
How does the esc know it's a Delta t
Or Y
Do escs work with both Y and triangle? Or are there specific escs for each one?
my reply is a little late but there is no difference as far as ESCs go. it's effectively the same as rewinding for a different Kv.
@@Skooteh thanks man, it's never too late for knowledge
Does this arrangement increase the running temperature of the motor?
I believe so. Since the voltage per phase is divided by √3, the current per phase must increase by √3. Because P = I^2R the temperature will most likely increase (triple in theory).
No, you are only changing (lowering) kV but current limit remains basically the same as it depends mainly on the copper fill between stator teeth. You'll be able to use a larger prop as it will run slower but very little change in power. If you keep the same prop it will actually run cooler.
More current = more heat
I have a motorcycle magneto with 18 poles. I would like to make it to a bldc motor with low rpm 1500 rpm is enough and with a high torque let me say 300to 400 watts with 12 or 24 Vdc input . Is there som one who can give me the information?
Is this really works or not.. i mean did somebody gave it a shot.. i do not want to change the windings and again rewind because of a fail..
super
i am no expert, but how do i know if my motor is a delta / wye phase..?
Gut joss tenan
you didn't show taking appart the motor
Hi we have a toy speedboat racing here in our area, im interested in improvising dc motor to a highest speed. Buy i dont have any background in rewinding.
losermons if you dont want to rewind also consider using gearing to increase your rpms. You can buy spur gears for this
ericinventor thanks for the idea, do you sale that kind of motor and the torque like thing?
losermons I dont sell anything directly. But you can buy these motors and gears on hobbyking.com
ericinventor thanks for the link, will try this.
What if i wanna increase the rpm?
prathamesh kalaskar if your motor has a Delta winding the only option would be to rewind the complete Motor.
Pls reply, will the Wye winding damage the ESC
No, both winding types can be used with the same esc. Changing the winding will not damage the esc
@@ericinventor pls tell how did you remove the stator from the motor base
tldw: "rewind" is changing delta to star
I appreciate the upload, but I would recommend a script because your missteps in speaking makes it hard to follow at times.
This video is a mess. Also, while you can do this, it's pretty important to understand how much different the motor will be. He says that one loses a little rpm. Yeah right. You lose about half your rpm. Imagine those who think they want a bit more rpm and to the opposite based on this video. They will more than likely end up roasting both their ESC's and motors. Yes you can change the configuration, but one damn well needs to understand what the drawbacks are.
@@AB-80X@AB-80X It accurately indicates the initial and final RPM values...
Also, it shows the calculation to determine the RPMs we will get by doing this modification.
So you'd have to be really stupid not to understand what to expect.
I am French and this seems totally obvious to me despite the speaking errors..🙂
power in delta is 23W and in star low to 15W. Only you don't saw!
Then we need Ac generators that make the most electricity possible for required torque to operate.
Electricity surpluse will then depend on gear ratios and the friction between. Luca oil works good. High torque low ratio dc spinning multiple ac generators. Electricity produced from some of these generators will then be used to power and charge the dc high torque motor. The rest will be surplus electricity.
Didn't you mean to say divided by rot 3 (at 3:33 minutes)???
Wye ? Should this not be a Y-configuration?
You drew the right hand schematics upside down.
he he... ;)
I just saw a video comparing two electric motor powered drivers. One had more torque and less RPM and the other had more RPM and less torque. I wonder if the manufacturer used this method? th-cam.com/video/l7hd4rKf2us/w-d-xo.html
please delete this video! its wrong information and just misleading!! you dont get more torque, you get 3 times less power since u get sqrt(3) less voltage and sqrt(3) less current in Y-connection, overall you have only 1/3 of the power!
Haha you are complete wrong I think coz everyone is saying wye winding has more torque and less rpm than Delta winding.
Please delete your comments,
@@ramadavince6611 He is 100% correct. The Delta motor draws a lot more current vs. a star configuration. Yes, if you have two motors with the same KV but one with D and one with Y, the Y likes timing a bit better and will have ever so slightly more punch off the line. But it should also be noted that the difference is so minute that most will never notice. Sure if you run SAW boats, there's something to gain, but KV is otherwise the key factor to consider.
You need to understand one thing when it comes to electric motors. Amps is torque, pure and simple. And what you drop when you do what this guy in this video does, is to almost half the amps. You make a statement based on what "others say", but those clowns are usually also those who say idiotic stuff like "an electrc motor has a flat torque curve". They know nothing and shouldn't flap their jaw.
If you want low end grunt, i.e torque, you need to look at the motor you can get with the highest amp draw per kv. You see a lot of people choosing the TP Power 4070CM motor for their 1/8 scale setup, because they they think it's the dogs danglies. That is correct if you're a speed runner and run the motor on top rpm. But for most, it makes little sense.
Here's an example.
TP 4070 CM 2200KV on 6S which many run. That runs 264 amps max. So that's about 5861 watts on 6S. Now take a regular TP 4070 with a 2250 kv rating and look at the amp draw. Even though these two motors are fairly close in KV and many think one is more powerful than the other, that's not always the case. The regular motor will take 318 amps. So at the end of the day you end up with 1200 more watts and much better torque. Yes, the 4070 is capable of delivering 9000 watts peak, but it needs 34 volts to do so. And while you get more rpm, due to higher voltage, you don't get any more torque. Amps equals torque, and volts equals rpm. Drop the amps and you reduce torque.
ChillingLu is spot on and this video is nonsense.
I'd strongly advise you to read some books rather than listen to incorrect information from people who think they know, but don't.
@@AB-80X bull shit.. you can't said this is torque.
Eg. A 5000 watts motor one with high rpm and the other with low rpm but high torque.
Torque (NM) =9.5488 X power (watts) ÷ speed (rpm)
Also. Power (Watts) = Torque (NM) X speed (rpm) ÷. 9.5488
Do I still need me to do the solving and explaination!??
Watts= Torque X rpm ÷ 9.5488
Pointless video just get a motor with lower kv you automatically get more torque less rpm