I don't know if anyone has explained this yet, but the problem is magnetic induction in one moter feeding inverse flow into the other. It is creating an oscillation back and forth between the two. As one spins faster than the other it acts as a generator to the other. This is demonstrated when you turn one by hand the other rotates in the opposite direction.this means the moters are constantly fighting each other. If you wish to run two on the same controller you could try either run them in series while doubling your voltage or add some capable diodes to prevent backflow. I would recommend two moter controllers however. One side effect of this is the dynamic breaking, so coasting would be an issue.
I dont think you know how these works yes they dont work together under load I tried but you cant connect 3 phase in series or ad a diode to a ac motor
Clearly people don't know the controller for brushless (AC) uses back feed or hall sensors to know how the motor is positioned. You can't hook 2 together and have the 3 phase timing correct for both. Now brushed (DC) motors you can hook up in parallel and it will work.
It is possible but the controller needs to be modified to stop the feedback from one motor into the other. Open the controller and double every output stage (at least you'll need another 6 N-Channel FETs plus 6 times the SOAR circuit) That way you give your controller a second Motor Output that doesn't feed back.
By the looks of it, it seems to make more sense just to add a second speed controller ( or one designed for dual motor setups.) Either way, it's still a good experiment and I'm glad you took the time to figure it out so the rest of us don't have to
The wise thing to do would be to use two speed controllers and two motors connected to a single throttle source. That's how quad copters are built. Each motor has its own speed controller, and the speed controllers are synchronized when you calibrate throttle position.
blise and chris you are both right but its grossly under powered either way that's a 250w controller and (2) 250w motors in parallel whcih makes them running about 125w a piece. also by adding the other motor you are adding resistance (ohms) to the inner workings of the controller. you've effectively doubled the work that the controller has to do to put out that same 250w. it might work but not for long ESPECIALLY under load.
Nice. I’ve actually did the same thing but instead of one controller I did it with two 48v controllers and 2x 1000 watt hub motors. and rewired the controller to work with one throttle. My goal was for more torque but also gained a little bit of more speed from 28 mph to 34 mph
@@vladimirryder5195 yea I did use the same battery for both controllers I also made it work with two separate batteries for each controller as well but I prefer the single battery instead.
@@tsmithurst yea I did use the same battery for both controllers I also made it work with two separate batteries for each controller as well but I prefer the single battery instead.
Your assertion at 9:29 is very correct. I was very glad to see that you do not recommend doing this. There are other reasons why this is real bad in real word usage. Watch what happens when you connect the 2 wheels to a common surface where the cant readily slip between each other. Or you can try using a chain or cog belt between them. In other words locking them to try to spin alike. You will burn things because the motors are never identical. I did these tests years ago with help from Neu Motors and Castle Creations. The noise you are hearing is a harmonic vibration because of the difference between the motors. Best way to do this cheap is use a common feed to separate controllers. But you can still get fighting between the 2 motor systems because of motor differences. Now I had great results using the hall effect switches as regulators to make the separate motors spin at the same speed and stay synced. But that took more processing from outside the controllers. Now this could be accomplished with the use of Raspberry Pi or the like.
these motors have one way clutches, so one will drive and not the other until the tires slip. if load increases and causes a speed decrease, both motors speed decrea, so only the wheel with the bigger dia tire drives.
Will George Interesting. So you lose drive if one wheel out speeds the other but you continue to drain power from your battery. That is a model of inefficient behavior in an electric model. Also the motors are still in essence still fighting each other in my book. The drive sides will always be hitting upon the other. I think it far better to control one then use the Hall effect switch to trigger control of the other. Then the motors will be synchronized. At least that’s how I see it. Maybe I should pull out some parts and revisit this issue.
This procedure has been done by electric kick scooter with a dual motor like the Dualtron and others. Mine has a dual drive motor but use only one controller with the same kind of configuration as shown in this video.
Running both like this will be fine but they will be noisier under load than normal as no hall effect sensors are used. Controllers are cheap, so it would make sense to use 2 controllers, then you can use the hall effect sensors. They can both be connected to the same throttle without issue.
Very nice sir, now you kmow im not lying.. We used 1kw controller on 2 500watts hub motor. I think this setup will burn the controller if the 2 motor have load. Thank you sir
@@BORNFREEININTHACD Difficult setup! Though probably not what you want to hear the easiest, troublefree setup would be a single motor/controller front wheel drive. Spitballing here but option two would be a two controllers/two motors probable equipped with hall effect position sensors for both rear wheels. Would need some circuit/microcontroller to act as an electronic "differential" to keep both motors synchronized. Just a semi-educated guess. I have more then 15yrs of BLDC motor/controller experience but not in this application.
@@barthchris1 I have a dual motor electric kick scooter and I looked inside its only one controller the same configuration as this video. Its been using by the E scooter manufacturer with a dual motor.
I suspect this’d be a lot worse on an actual bike. In this setup, the motors are free to ‘align’ their phases, as they’re spinning in air; on a bike, they’d be forced to travel the same speed (staying out of phase) or, even worse, to travel at different speeds when cornering.
I would think there would be miscommunication with the hall effect sensors. They have to be able to tell the motor where the windings are but if both motors are in different positions the controller won't send a proper signal to the motors.
I know this video is from four years ago. In that time period commercial e-bikes with dual hub motors have come to market. I have one. Mine is an EMX-Xtreme 500 from Fabulous Ebikes that has two 500w hub motors running on a single KT controller. KT (Kunteng) sell a controller designed to support two motors. In use I'm finding the set-up works really well. With each motor having 80Nm of torque the bike has relatively great acceleration and hill-climbing. On level terrain it appears both motors just share the load put on them by the pedal-assist settings. I can switch on or off the front motor while riding. On level terrain, switching on the second motor does not double the amperage draw. It stays practically the same whether one motor or two. On the EMX-Xtreme 500 the bike comes standard with a 48v 30Ah (1.440Wh) battery. With that I've had real world ranges per charge of 110.4 miles to 156.9 miles. Fabulous Ebikes also sell models with 60v 23.4Ah (1,400Ah) battery and a pair of 750w hub motors, again with a single-controller solution.
The motors are out phase. Probably 30-40% of the power when both motors are running is canceling out on the wire. You have to have either the sensors or the return signal developed by ESC aligned, so they fire the correct polarity at the correct time for both of them. Probably be easier to add sensors if there not already in there.
I knew the experiment result before you started it, because of the physics of running BLDC without sensor. Of course, it's no point in connecting sensors together. This setup will work only in case the motors are ideally synchronized. Any small deviation will lead to oscillation in both motors and reading of feedback by controller will be something weird because rotors are in different positions. This "strange sound" is resonance of this system and in fact it sounds strange not only in resonance. All the time it's consuming excess power to keep oscillations going (but rotors are trying to sync). It's OK to some point when motors are rotating independently without ground contact. If you try to place them on a bike and turn somewhere, there the biggest problem will occur because motor speeds will be slightly different. They can behave unpredictably.
@@TechMasterRus Τhis idea comes from many subscribers, because they find it hard to believe that it will not work properly if we connect two hub motors to one controller... and secondly, there is no video on RUclips to prove it, so I figured it out and created that Video.
Twin 350w hub motors in fat wheel downhill bike with 24v 500w bottle and rear rack batteries. Rear rack holding controller unit. All cables routed through jumbo alloy frame. Bluetooth the display and speed sensors. Thats a sensible build.
Very interesting result! It points to high motor losses and ways to improve it. That fact that total losses are more than the sum means that there are high losses in the controller that increase as more motors are added. This will probably be due to the conduction losses in the controller it suspect, more investigation is needed.
with 2 controllers you still splice in both hall effect sensors for one controll, this is all you had to do and they would sync. In addition they are both running the same direction, one side if used on a trike would require you to swap any 2 wires on the motor going backwards around.
Like stereo, harmonics on two slightly different frequencies due to the reasons you explained. However your test stand may play a part in this as well but only testing would tell for sure. Also, what if you added a third then a fourth hub on this stand and see what it sounds like then. This test was very interesting. Thank you.
How about mounting it to a common axle? I'm thinking of placing two direct drive motors from a washing machine (which are not the same as these but also BLDC) on the same axle and connected to the rear wheel via a chain. My theory is that if I place hall sensor wires to one of the motors and align them properly in phase they would turn just fine. I'd use a 2kw controller in that case.
Induction resistance and feed back. The pluses have a feed back and you're feeding them to the other motor, there is a build up which amounts to the "losses" you saw which is around 50% of the power (cycle). Put on diodes and a load cap. Then it will work fine. Isn't the controller and motors miss matched?
Thanks for a great experiment! Newby here. I was considering upgrade options to a 750W48V folder, adding a 500W36V front hub in parallel on a shared 35A controller! hahaha... Maybe just add a 52V20AH batt-w/blender in a rackbag and upping the controller from 22A to 30A? Seems easier adding batteries to a single controller than adding motors...
I have 2 hubs at 22amps each 36v, I use 2 controllers and one throttle you only need the throttle signal wire on the 2nd controller, obviously, top speed isn't increased but torque and acceleration are great fun but due to lack of weight over the front wheel it spins on hard acceleration from a standstill and the extra weight is a downer. for the extra weight, I'd just buy a new controller with higher amps as long as your battery will take it, but it looks cool with 2wd and lots of people are interested and ask questions if you like being sociable.
Brushless motors cannot be connected in parallel or in series. That would only work if the motors were mechanically connected to each other in exactly the right position and the Hall sensors were only connected to one motor. Exactly this is not possible with our intended use. Motors with brushes, on the other hand, can easily be connected in parallel or in series.
This was very helpful info since I own a HUNTER QUAD electric scooter. This scooter has 2 motors on the front wheel and 2 in the rear wheel. Each motor rated at 72V 3500w for a total of 14000 watts but it uses 4 X 45Amp controllers. I am currently modifying it with 2 controllers, 1 Sabvoton 72200 for the front and 1 for the rear with a shared thumb throttle. Here's a the video of the scooter and I am the person you'll see speaking on the video. ruclips.net/video/aBQfs0V3wos/видео.html
1. Peak current for one motor was 0.95А. 0.95Ax37.7V~=35W this consumption we see when the motor is under load, starts to spin. After spinning up the consumption falls down to 22Watts. 2. For two motors it was 2.2A(82W) and 1.8A(68W). It is 41W and 34W per motor. Thus two motors in parallel are "less power effictive" than one in about 41/35( or 34/22)=1.17(1.54) times. 3. This demonstration shows only basic values. We still don't know what it means in real life for bike or scooter. For example with two motors there can be less speed and more power(higher acceleration, more average speed on rolling road or mountains). 4. 41W is not dangerous for 250W motorwheel. 5. 2.2A is not dangerous for 15A controller. 6. We don't know minimum resistance limit load on controller and don't know the wheels resistans and that is why it can be dangerous for controller. But i think if it works then it can be used after some temperature tests. Why not?
well done for the experiment i think we can't run the two motors with one motor feedback hall sensors because it is nearly impossible as you said in your video to have the same position and same speed at the same voltage to synchronize the two motors it is like you run one of the 2 motors without a feedback just rotate the field that is the reason of the crawling and cogging (strange sound) so i think we can run the two motors without problem only if we synchronized the sensors signals of two motor (maybe AND gate for the same sensor in both rotor for example (h1motor1&h1motor2)) so we guaranteed the same position of the two motors
Well with old school tech it's supper easy. Never tried with modern motors big enough to run a bike or scooter. However brushless setups in models are possible so long as you stay inside your power limits for the speed controller.
[Update on my build below] Great video and awesome (if utterly confusing and contradictory comments!). I'm trying to build an electric hand truck (i.e. convert one to electric) and although several companies make them, the ones they make are over-built for my purposes and VERY expensive (since they're build for industrial use.) I need one to help carry loads uphill on an elevated boardwalk to lake cabin. As far as I can tell, I want low speed and auto-braking and short duration (compared to scooters, etc). The distance is a few hundred feet uphill x 3-5 trips, the weight is
Good to know, thanks for testing this. I've always wondered what a two hub drive would feel like, but figured the added weight wouldn't be worth it. It would probably make sense to have extra weight at the wheels for a very high power / high torque setup in order to keep traction. I've also been wondering if we ran a 1000w mid drive with a 1000w front hub motor would they compliment each other?
I don't think a front hub and a mid-drive should be mixed as you will never sync the two one will basically always be doing most of the work. You would never be able to sync the Wheel RPMs and depending on your front drive this may actually cause drag on the front wheel.
This could work if you regulated the current to produce the desired torque split. But you would need a computer to set the individual throttles. Your input to the computer would basically be a desired total current and it would adjust the throttles to each motor to achieve the desired total and split. That's pretty much what happens on the dual motor Teslas.
The explanation to the big loss is magnetic induction. One motor create opposite flow of current to the other motor. To overcome the induction the control produce more current to overcome the induction to make the speed of both motors the same. Thats where the 26w came from. Also the battery will suffer in when you use it with a load.
As a guess I would say its because of the Motor Sensors. The motos get to a certain speed and one of the needs a slightly differnt timing, but the ESC is prolly only doing the toiming based on one of the motor's feedback, then pulsing it the way it thinks it needs. Another intresting phenomena occured but wasnt mentioned. I noticed when he put load on the left motor, the right hand motor slowed down too. Thats going to be to do with the sensors, ill bet! Did you put the sensor wires in paralel or series? or not at all, or only hooked up one motors sensor wires?
This necessarily was running either sensorless, or with the halls from one motor connected. In sensorless, the determination of motor position will be off, because current & voltage are used to determine that, and connecting two motors obviously throws that off. The result is cogging which will vary in severity from loss of efficiency to burning out both motors and possibly the controller.
The sound difference is just an acoustical phenomena, since the two motors, even if are same model, are not perfectly equal , so there is some sort of beats between the two sounds that are not perfectly the same
Perfectly fine for a slippery or dirt surface condition riding but not for pavement just like an all wheel drive vehicle in the old days when the front and rear wheels were locked together they bind up and often to get out of all wheel drive you had to back up.
yes that will work but remember they are sharing the voltage and current so it wont be double power or speed,it will likely actually preferm in real world worse than a single one unless you get an unlimited controller giving full battery voltage use with a continous 50 amp power handling rating
after alot of trial and error we found that using a cycle analyst ver 2.5 or 3 was the only true way of syncing controllers and motors also lets you set different front and rear power distribution for different terrain and power needs,or even run one in constant generator mode to get bit more ride time.
Not sure this is a good idea due to back emf. I would say under load the controller, and probably the motors will run hot and with low efficiency. The controller uses the back emf for timing, and with two motors connected the timing won't be handled correctly. Interesting concept to try, but in reality it won't work well, or for a long period.
I tried using two motor controllers and two motors connected to one throttle. There must be some kind of feedback because the two motors spin and the power is good, then the controllers immediately turn off or go into so protective mode and are unresponsive. If I turn battery off and on they work again for about one second. Either motor and controller by itself works fine, but together they somehow interfere. The motors are configured (via activating learning mode) to spin in opposite directions since they are left and right wheels and their mounting locations makes that a necessity.
Hey, man, I saw in the video that you put both in parallel engines, I have to tell you that if you put a diode on his way out of any of you both engines would take the electric contrast between the two, and he would not stop, no one would move when motor tour. A greeting from Spain and I feel the translation.
Sry if this question has already been answered ... with having only the stator windings in parallel and only one motor having the hall sensors connected to the controller, what are the result in Power consumption? My thoughts ... having dual conflicting input signals is probably having an effect on the controller output. With only one unit giving feedback to the controller, the output frequency will be equal to both units, as the second is purely slave unit with the results being a closer to a doubling of the overall current draw. Now if that slave is proportionally under more load, what is the outcome?
could there be some -off road applications , such as -farming-mowing - hillclimbing , trail riding -ect...that allow for constant "wheel slip"? jeeps of yesteryear were kept in 2wheel drive , -on the pavment-because of simular reason , but off road the wheels slipped in the soft dirt/sand . no problems there , in the 4wheel mode.
id bet that with some sort of suppression it would work. id bet the resonance is because the motors become slightly out of phase and start generating their own voltage which is sent to the other motor and back causing both to oscillate. could also probably wire them in series if you had enough voltage.
Question someone explain please , i thinking about adding duel hub motors kit to my wheelchair from a factory are the compatible with each other ? I'll like to know before purchasing this unit
Free spinning, it’ll “work”... but unless the motors are PERFECTLY linked to each other (to prevent drift) it will cause issues for power, efficiency, noise and reliability of the controller.
Look at how a single works before you connect dual motors. The speed control sends pulses for motor to engage rotation, then motor sends back info about its location relative the stator coils. This info tells the speed control when to send next pulse. When you connect another motor you also get another location info about where the motor are. These signal info may collide or create an duplicated info so the speed control send pulse for a double speed that no motor are at. This configuration will never work good.
Lots of interesting comments on what the issue is. Brushless dc motor controllers need to get feed back from the motor to know the position of the rotor, this feed back is obtained in one of two ways, either from hall sensors or from from the normal voltage generated when a motor is rotating (back emf). When the controller knows the position of the rotor, it then knows when to apply power. The motor has three phases and the controller has to monitor and manage each of them. When you connect two motors to a controller, it will be getting feedback from both motors and unless they are both phase syncronised (unlikely) they will not run properly as the duel feedback will cause the controller to not correctly apply power to one or both motors.
@@boingo001 No. If a motor has brushes, they control which coils are getting current, at the correct moment to cause rotation, and the current could then be "chopped", but brushless motors, of course, don't have brushes, so current control through the coils has to be done electronically
Problem with this is when you load those motors since only one gas feedback loop The one with open loop can lose its position and it will start to draw huge amount of current without transferring power And there is a big risk of blowing the motor or controller
Series..??? You mean in parallel, yes i know that you can not connect two hub motors in parallel, also i do not recommend that... This video is testing proof for one subscriber..
Running these on the same axle will cause all kinds of issues with torque transfer. An equivalent effect being that of wind up in a locked axle on a car going around a corner. Everytime you turn the wheel you're going to be fighting the motors trying to push the wheels straight again.
two motors connected in paralel -become motor-generator system with oscilation of mechanical energy between one and another - it cause looses, if they will be on one wheel or even maybe on real cycle - Imho it will fixed by flat and dependent rotation of both motors, without ping-pong energy exchange between motors
Yes, but badly. :P I tried this with a controller with hall sensor support. That particular variant ran faster with hall sensors enabled. So I lost a lot of top speed.
You're drawing twice the current through one controller rated for one motor(so i can only assume). Once you let the smoke out you can't put it back in (lolz). The moment you try this with a decent load (let's say a go kart) you will draw around 6x the rated current at zero RPM from BOTH motors and things won't end up well. You want two separate power sources and two separate controllers for PWM motor control applications with ONE throttle connected to both PWM CONTROL circuits (in Parallel). This will eliminate any frequency, resistance, and inductance/capacitance differences from interacting with each other through one modulator. Too many factors contribute to imbalances such as different wire length, internal motor winding insulation condition, rolling resistance of bearings inside the motors, defective parts inside of cheap Chinese controllers...all affecting the operation of the capacitors and voltage regulators ect.. inside the controller.
Add for bouth motors, one way diode's and they will work! They act like this because one motor is trying to charge the other one so on....they act like a generator...if they have one way diodes, they will work 100%! Ty !
i think the bad sound his just an acoustic problem of phase, when the 2engine have the same speed, the frequency of sound have an "resonance" called phase, because its the same sound but with a short delay because the distance (of sound captation) is not the same…. if you find the frequency (like wood's frequency for example and try ;-) ) you can maybe erase the noise…. sorry for my poor english
It's green signal wire to a positive the same watts. I was trying ground and it kept reading error. Took multimeter, found out the signal is positive and wired it up and works now, so positive to signal will give you your dual or single mode
No loses watt....but paraller 2 motor = look like delta wire more amp.. you need to drive the motor Its not simple calculation 22+22= 44 Becouse the resistant wire 1 motor, when you jointed the wire to another motor make it low resistan If you jointed 2 motor its made more biger induction n more biger back EMF ( mybe not same time back emf betwen 2 motor) make your motor sound like there is the load so more current you need to supplay this motor
I like the build, but let's have some perspective here on the charging. 1,402 comments here, and not one has looked at the maths. His solar panels added up is less than 2 sq meters. They look like old technology panels. Modern panels produce 150 - 200 watts per sq meter. Let's be generous and say the vehicle can generate 300 watts in full sun. So 12 hours of full sunshine - could generate 3.6 KW hours His 2 hub motors will be at least 1,000 watts each. Assume 50% efficiency for the whole system. So 12 hours of charging in full sun = 3.6 kWh. (Kilo Watt Hours). The motors together are 2KW. With 50% efficiency, a full 12 hours charge gives 3.6 *50% /2 =.72 hours That equals at best 43 minutes driving time per day. In practice, I would be impressed if he got 10 minutes driving time from 12 hours of solar panel charging. I know the motors won't be at full power all of the time, but they do have to push around a lot of metal as well as the driver and passengers. These motor were designed to drive a pushbike, so will be heavily loaded in this application. This vehicle will need to be charged by mains or generator to be of any use. The solar panels can drive electronics - headlights radio etc In addition, he uses bicycle wheels. Bicycle wheels are designed for vertical stresses only, no sideward stresses. He will get away with it for a while by using fat tire wheels because the spokes in the rim are splayed from side to side. Every time he turns, his wheels endure severe side stresses. The wheels will buckle in time. Bicycle wheels are designed to lean when turning, so there are no sideways stresses. The other problem with this build is the rear differential. You cannot drive the 2 motors with one controller because the motors will be forces to move at exactly the same speed. The two rear tires are locked together so when turning these motors will experience severe stress forcing tire skid. It might work for a while on a dirt road, but on a modern road there would be severe motor stress and tire wear. In addition, if there is more weight on the back wheels, the steering might not work at all. The alternative is a controller for each wheel, but that requires a very complex hardware and software management system Mr Musk, Mercedes, BMW, GM etc can design these systems, but it is not in the scope of a backyard inventor. Strong sunshine pushes out around 1000 watts per sq meter. Typically, commercial panels today are about 20% efficient. Even if we had 100% efficient panels, there is not enough energy from the sun to power a family car by itself. With extreme engineering - carbon fibre frames, super efficient motors and a vast aero dynamic solar surface with very expensive panels, it is possible to create a vehicle that will carry 1 person in a desert environment with good roads. There is a biannual race for solar-powered cars which takes place in different deserts around the world since 1987. In recent years, Darwin to Adelaide in Australia. en.wikipedia.org/wiki/World_Solar_Challenge#2015 These cars do work entirely on solar power, but are so big in area and so light that they sometimes get blown off the road in windy conditions. Here is a typical solar car. pt.m.wikipedia.org/wiki/Ficheiro:Solar_Car_Tokai_Challenger.JPG Usually, one of the Dutch teams wins but in 2019 they were beaten by the Belgians. 2019's race video. ruclips.net/video/5KD4QQUUv_w/видео.html
I don’t know 🤷🏾♂️ Electronics that we’ll never went to school for it but I believe it’s because your causing the controller to loose Pressure or in other words it’s compensating 34% in Watts because two motors to that controller is like opening a pipeline twice it’s size all of the sudden. In doing so, to fill the pipe to proper pressure, you would need More Energy... Another example is If I have a tank that I can fill in 1 hr with whatever power I have and then out of nowhere, I have to fill TWO tanks in the same time, I would need a pump that can pump twice as much and bigger hose to compensate otherwise it will burst. So your motor is acting like a BIGGER motor than what it really is to compensate for the load the motors are asking for🤦🏾♂️😎 I do think 🤔 💭 I am making sense here😂😂
David depends on how fast you want to go. The more amps, the more Torque. The more Voltage, the more speed. You need a battery that can handle the power the controller draws. You first have to choose a safe voltage. Most run motors in between 48v-72v. More than likely, you want to get a battery 🔋 capable of 60-80 amperes but get a controller that draws around 60amps to have cushion
David 72v fully charged is 84v. Usually motors run more efficiently with higher voltages. The thing is when you up the voltage, in theory, you must drop the amperes or Vis-a-vis. If not, the motors will heat up much more quickly depends on how much power your draw through the throttle signal. 48v fully charged is 56.6v or 58.4v if you have 14s or higher battery 🔋. So you must connect them to the battery in parallel so the voltages stay the same.
The sine waves sent to the motor are affected by the motor itself, power is induced in the wires from the magnets passing the lesser powered coils during the cycle. It become an interference pattern with 2 motors
So what did you do with the other hall sensor wires coming from the other motor? I also imagine both hub motors need to be identical and controller needs to handle double the amps of the motors
Question I am wanting to make a 4 Wheel drive cart with 4 Independent drive hub motors (48v 800w (rated 600w, max current 30A) geared hub motor for electric wheelbarrow) is it possible to have one controller for this?
No way... the best you can do is to find 2 hoverboard controllers which have 2 outputs for a motors each one... but there you must program them first..
Thanks for testing this. I wondered about building a trike with two motors on the rear wheels, but I think it will be problematic regulating the power to each motor in turns, slippery road etc. I suppose a differential would be necessary?
@@timtreffry7718 i have also been working on a trike problem is how to vary power on the real two hub motors on turning or i can be using differential and a bigger motor ,robert murray smith showed a freewheel differential for trike but it cannot be reversed so i was thinking of using two motors front wheel hub motor and rear wheel geared motor on differential. Now , the issue is to control them with a single controller and throttle.
I don't know if anyone has explained this yet, but the problem is magnetic induction in one moter feeding inverse flow into the other. It is creating an oscillation back and forth between the two. As one spins faster than the other it acts as a generator to the other. This is demonstrated when you turn one by hand the other rotates in the opposite direction.this means the moters are constantly fighting each other. If you wish to run two on the same controller you could try either run them in series while doubling your voltage or add some capable diodes to prevent backflow. I would recommend two moter controllers however. One side effect of this is the dynamic breaking, so coasting would be an issue.
And also if these motors are brushless you can't control them with only one controller I think
I dont think you know how these
works yes they dont work together under load I tried but you cant connect 3 phase in series or ad a diode to a ac motor
Clearly people don't know the controller for brushless (AC) uses back feed or hall sensors to know how the motor is positioned. You can't hook 2 together and have the 3 phase timing correct for both. Now brushed (DC) motors you can hook up in parallel and it will work.
It is possible but the controller needs to be modified to stop the feedback from one motor into the other. Open the controller and double every output stage (at least you'll need another 6 N-Channel FETs plus 6 times the SOAR circuit) That way you give your controller a second Motor Output that doesn't feed back.
@@sebastianweinert3802 that would be two in one controller driver .. I think :)
By the looks of it, it seems to make more sense just to add a second speed controller ( or one designed for dual motor setups.) Either way, it's still a good experiment and I'm glad you took the time to figure it out so the rest of us don't have to
0:31 I've never seen a motors looking so happy before
nice one
The wise thing to do would be to use two speed controllers and two motors connected to a single throttle source. That's how quad copters are built. Each motor has its own speed controller, and the speed controllers are synchronized when you calibrate throttle position.
Yea but quad copters have to regulate all motors independently. The bike would be finde with them running the same speed.
Newsflash ! This isn't a Quadcopter !
blise and chris you are both right but its grossly under powered either way that's a 250w controller and (2) 250w motors in parallel whcih makes them running about 125w a piece. also by adding the other motor you are adding resistance (ohms) to the inner workings of the controller. you've effectively doubled the work that the controller has to do to put out that same 250w. it might work but not for long ESPECIALLY under load.
It would significantly bring the price up.
@@christopherroberts22 you should have said that before I tried flying off the roof.
Nice. I’ve actually did the same thing but instead of one controller I did it with two 48v controllers and 2x 1000 watt hub motors. and rewired the controller to work with one throttle. My goal was for more torque but also gained a little bit of more speed from 28 mph to 34 mph
Forgive me if this is a stupid question Did you wire the same battry pack to the 2 controllers?
Did you wire the same battry pack to the 2 controllers?
@@vladimirryder5195 yea I did use the same battery for both controllers I also made it work with two separate batteries for each controller as well but I prefer the single battery instead.
@@tsmithurst yea I did use the same battery for both controllers I also made it work with two separate batteries for each controller as well but I prefer the single battery instead.
may i knw how to connect two controllers to work with one throttle..Thank you
Your assertion at 9:29 is very correct. I was very glad to see that you do not recommend doing this. There are other reasons why this is real bad in real word usage. Watch what happens when you connect the 2 wheels to a common surface where the cant readily slip between each other. Or you can try using a chain or cog belt between them. In other words locking them to try to spin alike. You will burn things because the motors are never identical. I did these tests years ago with help from Neu Motors and Castle Creations.
The noise you are hearing is a harmonic vibration because of the difference between the motors.
Best way to do this cheap is use a common feed to separate controllers. But you can still get fighting between the 2 motor systems because of motor differences.
Now I had great results using the hall effect switches as regulators to make the separate motors spin at the same speed and stay synced. But that took more processing from outside the controllers. Now this could be accomplished with the use of Raspberry Pi or the like.
these motors have one way clutches, so one will drive and not the other until the tires slip. if load increases and causes a speed decrease, both motors speed decrea, so only the wheel with the bigger dia tire drives.
Will George
Interesting. So you lose drive if one wheel out speeds the other but you continue to drain power from your battery. That is a model of inefficient behavior in an electric model. Also the motors are still in essence still fighting each other in my book. The drive sides will always be hitting upon the other. I think it far better to control one then use the Hall effect switch to trigger control of the other. Then the motors will be synchronized. At least that’s how I see it. Maybe I should pull out some parts and revisit this issue.
@@michaelmeisman4731 I think it would be better to drive one motor only, then bring in the other if it is needed. really need 2 controllers
This procedure has been done by electric kick scooter with a dual motor like the Dualtron and others. Mine has a dual drive motor but use only one controller with the same kind of configuration as shown in this video.
If you had a 500W controller would that work?
Interesting, I had not even thought about the possibility of running two motors on the same controller, but I find it an interesting experiment.
I have done such a thing although they are 2 hub motors on the same wheel wired in opposite directions. ruclips.net/video/ViZZ0npJKg4/видео.html
Just because you can do something doesn’t mean you should do something.
old time big cassette recorder feeling
Oh yeah spinny matron drums
Running both like this will be fine but they will be noisier under load than normal as no hall effect sensors are used.
Controllers are cheap, so it would make sense to use 2 controllers, then you can use the hall effect sensors. They can both be connected to the same throttle without issue.
not even one day past and I had my question answered super cool thanks to ev costumes for your time
That was good.
He learns the lessons so that we don't have to.
Well done.
.
Hi sir . How to make a speed limiter for ebike? Thank you..
I have already video for that...
Very nice sir, now you kmow im not lying.. We used 1kw controller on 2 500watts hub motor. I think this setup will burn the controller if the 2 motor have load. Thank you sir
Yes like this can work but i not recommend because like this you will have huge losses...
Price sir 36volt
Really it would? I'm trying to get my bike to synchronize with all three wheels moving with pedal-assist for my trike
@@BORNFREEININTHACD Difficult setup! Though probably not what you want to hear the easiest, troublefree setup would be a single motor/controller front wheel drive. Spitballing here but option two would be a two controllers/two motors probable equipped with hall effect position sensors for both rear wheels. Would need some circuit/microcontroller to act as an electronic "differential" to keep both motors synchronized. Just a semi-educated guess. I have more then 15yrs of BLDC motor/controller experience but not in this application.
@@barthchris1 I have a dual motor electric kick scooter and I looked inside its only one controller the same configuration as this video. Its been using by the E scooter manufacturer with a dual motor.
I suspect this’d be a lot worse on an actual bike. In this setup, the motors are free to ‘align’ their phases, as they’re spinning in air; on a bike, they’d be forced to travel the same speed (staying out of phase) or, even worse, to travel at different speeds when cornering.
I would think there would be miscommunication with the hall effect sensors. They have to be able to tell the motor where the windings are but if both motors are in different positions the controller won't send a proper signal to the motors.
I'm happy to see that I'm not the only one who knows about amp load increasing to cook the speed control under load.
I know this video is from four years ago. In that time period commercial e-bikes with dual hub motors have come to market. I have one. Mine is an EMX-Xtreme 500 from Fabulous Ebikes that has two 500w hub motors running on a single KT controller. KT (Kunteng) sell a controller designed to support two motors. In use I'm finding the set-up works really well. With each motor having 80Nm of torque the bike has relatively great acceleration and hill-climbing. On level terrain it appears both motors just share the load put on them by the pedal-assist settings. I can switch on or off the front motor while riding. On level terrain, switching on the second motor does not double the amperage draw. It stays practically the same whether one motor or two. On the EMX-Xtreme 500 the bike comes standard with a 48v 30Ah (1.440Wh) battery. With that I've had real world ranges per charge of 110.4 miles to 156.9 miles. Fabulous Ebikes also sell models with 60v 23.4Ah (1,400Ah) battery and a pair of 750w hub motors, again with a single-controller solution.
I wonder how they would act as two motor rwd cart. I would like to avoid using a diff.
The motors are out phase. Probably 30-40% of the power when both motors are running is canceling out on the wire. You have to have either the sensors or the return signal developed by ESC aligned, so they fire the correct polarity at the correct time for both of them. Probably be easier to add sensors if there not already in there.
I knew the experiment result before you started it, because of the physics of running BLDC without sensor. Of course, it's no point in connecting sensors together. This setup will work only in case the motors are ideally synchronized. Any small deviation will lead to oscillation in both motors and reading of feedback by controller will be something weird because rotors are in different positions. This "strange sound" is resonance of this system and in fact it sounds strange not only in resonance. All the time it's consuming excess power to keep oscillations going (but rotors are trying to sync).
It's OK to some point when motors are rotating independently without ground contact. If you try to place them on a bike and turn somewhere, there the biggest problem will occur because motor speeds will be slightly different. They can behave unpredictably.
Yes my friend we all knew the result... this video is a simple experiment. ;)
@@EVCustoms but how did you even have such an idea?) It's something like driving a car without differential, really, much worse...)
@@TechMasterRus Τhis idea comes from many subscribers, because they find it hard to believe that it will not work properly if we connect two hub motors to one controller...
and secondly, there is no video on RUclips to prove it, so I figured it out and created that Video.
Twin 350w hub motors in fat wheel downhill bike with 24v 500w bottle and rear rack batteries. Rear rack holding controller unit. All cables routed through jumbo alloy frame. Bluetooth the display and speed sensors. Thats a sensible build.
Very interesting result! It points to high motor losses and ways to improve it. That fact that total losses are more than the sum means that there are high losses in the controller that increase as more motors are added. This will probably be due to the conduction losses in the controller it suspect, more investigation is needed.
Try with wiring 4 diodes (2 for each motor), in order to eliminate feedback loop.
with 2 controllers you still splice in both hall effect sensors for one controll, this is all you had to do and they would sync. In addition they are both running the same direction, one side if used on a trike would require you to swap any 2 wires on the motor going backwards around.
Nice , i think you may Use a chunk diod at the end of the motor on the left to not give a feedback voltage and try again.
Like stereo, harmonics on two slightly different frequencies due to the reasons you explained.
However your test stand may play a part in this as well but only testing would tell for sure.
Also, what if you added a third then a fourth hub on this stand and see what it sounds like then.
This test was very interesting. Thank you.
How about mounting it to a common axle? I'm thinking of placing two direct drive motors from a washing machine (which are not the same as these but also BLDC) on the same axle and connected to the rear wheel via a chain. My theory is that if I place hall sensor wires to one of the motors and align them properly in phase they would turn just fine. I'd use a 2kw controller in that case.
Induction resistance and feed back.
The pluses have a feed back and you're feeding them to the other motor, there is a build up which amounts to the "losses" you saw which is around 50% of the power (cycle).
Put on diodes and a load cap. Then it will work fine.
Isn't the controller and motors miss matched?
You need to add diodes (big ones) between the motors. You have back emf current going from one to another.
I will make one video with diodes my friend..
Thanks for a great experiment! Newby here. I was considering upgrade options to a 750W48V folder, adding a 500W36V front hub in parallel on a shared 35A controller! hahaha... Maybe just add a 52V20AH batt-w/blender in a rackbag and upping the controller from 22A to 30A? Seems easier adding batteries to a single controller than adding motors...
I have 2 hubs at 22amps each 36v, I use 2 controllers and one throttle you only need the throttle signal wire on the 2nd controller, obviously, top speed isn't increased but torque and acceleration are great fun but due to lack of weight over the front wheel it spins on hard acceleration from a standstill and the extra weight is a downer. for the extra weight, I'd just buy a new controller with higher amps as long as your battery will take it, but it looks cool with 2wd and lots of people are interested and ask questions if you like being sociable.
Brushless motors cannot be connected in parallel or in series. That would only work if the motors were mechanically connected to each other in exactly the right position and the Hall sensors were only connected to one motor. Exactly this is not possible with our intended use.
Motors with brushes, on the other hand, can easily be connected in parallel or in series.
This was very helpful info since I own a HUNTER QUAD electric scooter. This scooter has 2 motors on the front wheel and 2 in the rear wheel. Each motor rated at 72V 3500w for a total of 14000 watts but it uses 4 X 45Amp controllers. I am currently modifying it with 2 controllers, 1 Sabvoton 72200 for the front and 1 for the rear with a shared thumb throttle. Here's a the video of the scooter and I am the person you'll see speaking on the video.
ruclips.net/video/aBQfs0V3wos/видео.html
Interesting to watch. Thanks for doing the leg work! Luckily the controller is the cheaper part.
1. Peak current for one motor was 0.95А. 0.95Ax37.7V~=35W this consumption we see when the motor is under load, starts to spin. After spinning up the consumption falls down to 22Watts.
2. For two motors it was 2.2A(82W) and 1.8A(68W). It is 41W and 34W per motor. Thus two motors in parallel are "less power effictive" than one in about 41/35( or 34/22)=1.17(1.54) times.
3. This demonstration shows only basic values. We still don't know what it means in real life for bike or scooter. For example with two motors there can be less speed and more power(higher acceleration, more average speed on rolling road or mountains).
4. 41W is not dangerous for 250W motorwheel.
5. 2.2A is not dangerous for 15A controller.
6. We don't know minimum resistance limit load on controller and don't know the wheels resistans and that is why it can be dangerous for controller. But i think if it works then it can be used after some temperature tests. Why not?
Very good explanation thanks for the video my Friend🙌🙂🤝🤝🤝
Thank you mate! nice channel by the way..
well done for the experiment
i think we can't run the two motors with one motor feedback hall sensors
because it is nearly impossible as you said in your video to have the same position and same speed at the same voltage to synchronize the two motors it is like you run one of the 2 motors without a feedback just rotate the field that is the reason of the crawling and cogging (strange sound)
so i think we can run the two motors without problem only if we synchronized the sensors signals of two motor (maybe AND gate for the same sensor in both rotor for example (h1motor1&h1motor2)) so we guaranteed the same position of the two motors
Great idea I can use that advice for my bike thanks😎
Well with old school tech it's supper easy. Never tried with modern motors big enough to run a bike or scooter. However brushless setups in models are possible so long as you stay inside your power limits for the speed controller.
Phases on two motors are not in sinc, so they technically misfire
on d.c.?
[Update on my build below] Great video and awesome (if utterly confusing and contradictory comments!). I'm trying to build an electric hand truck (i.e. convert one to electric) and although several companies make them, the ones they make are over-built for my purposes and VERY expensive (since they're build for industrial use.) I need one to help carry loads uphill on an elevated boardwalk to lake cabin. As far as I can tell, I want low speed and auto-braking and short duration (compared to scooters, etc). The distance is a few hundred feet uphill x 3-5 trips, the weight is
How about a used mobility scooter pulling a 4-wheeled garden trailer? Cheap and not a lot of work. And the kids love it with a big seat fitted.
Good to know, thanks for testing this. I've always wondered what a two hub drive would feel like, but figured the added weight wouldn't be worth it. It would probably make sense to have extra weight at the wheels for a very high power / high torque setup in order to keep traction. I've also been wondering if we ran a 1000w mid drive with a 1000w front hub motor would they compliment each other?
maybe, the weight might go abit off with the front but should be good
I don't think a front hub and a mid-drive should be mixed as you will never sync the two one will basically always be doing most of the work. You would never be able to sync the Wheel RPMs and depending on your front drive this may actually cause drag on the front wheel.
This could work if you regulated the current to produce the desired torque split. But you would need a computer to set the individual throttles. Your input to the computer would basically be a desired total current and it would adjust the throttles to each motor to achieve the desired total and split. That's pretty much what happens on the dual motor Teslas.
Hahaahaahah!!! Dumbest question of the Day ! well done ;-P
The explanation to the big loss is magnetic induction. One motor create opposite flow of current to the other motor. To overcome the induction the control produce more current to overcome the induction to make the speed of both motors the same. Thats where the 26w came from.
Also the battery will suffer in when you use it with a load.
As a guess I would say its because of the Motor Sensors. The motos get to a certain speed and one of the needs a slightly differnt timing, but the ESC is prolly only doing the toiming based on one of the motor's feedback, then pulsing it the way it thinks it needs. Another intresting phenomena occured but wasnt mentioned. I noticed when he put load on the left motor, the right hand motor slowed down too. Thats going to be to do with the sensors, ill bet! Did you put the sensor wires in paralel or series? or not at all, or only hooked up one motors sensor wires?
This necessarily was running either sensorless, or with the halls from one motor connected.
In sensorless, the determination of motor position will be off, because current & voltage are used to determine that, and connecting two motors obviously throws that off.
The result is cogging which will vary in severity from loss of efficiency to burning out both motors and possibly the controller.
I have tried too but in 500 watts and so far so good.
How kind I get some to buy in Holland
Yes, of course, this is possible unloaded but with any significant load imbalance on either motor your looking to fry some FETs.
Really?
Cool!! But I wounder if you could run in series instead of parallel.. would love to see this..
Very nice that you show this can be done. Perhaps you could try the experiment again but with a higher ampage speed controller.
Or higher voltage🙂
The sound difference is just an acoustical phenomena, since the two motors, even if are same model, are not perfectly equal , so there is some sort of beats between the two sounds that are not perfectly the same
Thank you man! Saved me alot of trouble!
Thank you mate..
Perfectly fine for a slippery or dirt surface condition riding but not for pavement just like an all wheel drive vehicle in the old days when the front and rear wheels were locked together they bind up and often to get out of all wheel drive you had to back up.
That's 4wd, not awd.
yes that will work but remember they are sharing the voltage and current so it wont be double power or speed,it will likely actually preferm in real world worse than a single one unless you get an unlimited controller giving full battery voltage use with a continous 50 amp power handling rating
after alot of trial and error we found that using a cycle analyst ver 2.5 or 3 was the only true way of syncing controllers and motors also lets you set different front and rear power distribution for different terrain and power needs,or even run one in constant generator mode to get bit more ride time.
Not sure this is a good idea due to back emf. I would say under load the controller, and probably the motors will run hot and with low efficiency. The controller uses the back emf for timing, and with two motors connected the timing won't be handled correctly. Interesting concept to try, but in reality it won't work well, or for a long period.
I tried using two motor controllers and two motors connected to one throttle. There must be some kind of feedback because the two motors spin and the power is good, then the controllers immediately turn off or go into so protective mode and are unresponsive. If I turn battery off and on they work again for about one second. Either motor and controller by itself works fine, but together they somehow interfere. The motors are configured (via activating learning mode) to spin in opposite directions since they are left and right wheels and their mounting locations makes that a necessity.
Hey, man, I saw in the video that you put both in parallel engines, I have to tell you that if you put a diode on his way out of any of you both engines would take the electric contrast between the two, and he would not stop, no one would move when motor tour. A greeting from Spain and I feel the translation.
with this sistem you can have a total traction on your bicicle , its a good idea good video
its alot different when you throw them on a bike and add all the weight. controller would burn out
👍
Very good vídeo bro!
Sry if this question has already been answered ... with having only the stator windings in parallel and only one motor having the hall sensors connected to the controller, what are the result in Power consumption?
My thoughts ... having dual conflicting input signals is probably having an effect on the controller output. With only one unit giving feedback to the controller, the output frequency will be equal to both units, as the second is purely slave unit with the results being a closer to a doubling of the overall current draw. Now if that slave is proportionally under more load, what is the outcome?
could there be some -off road applications , such as -farming-mowing - hillclimbing , trail riding -ect...that allow for constant "wheel slip"? jeeps of yesteryear were kept in 2wheel drive , -on the pavment-because of simular reason , but off road the wheels slipped in the soft dirt/sand . no problems there , in the 4wheel mode.
id bet that with some sort of suppression it would work. id bet the resonance is because the motors become slightly out of phase and start generating their own voltage which is sent to the other motor and back causing both to oscillate. could also probably wire them in series if you had enough voltage.
Question someone explain please , i thinking about adding duel hub motors kit to my wheelchair from a factory are the compatible with each other ? I'll like to know before purchasing this unit
Mr EV, apart from the uneven current voltage, are there any other problems, for using two bldcs with one controller??
Awesome you could make a dual-motor ebike with this!
I didn't recommend that my friend..
I know it's just an idea
Dual brushed motors work and are easy.
And can two controller work with one hub motor?
Hmmm.. nice question..?
Free spinning, it’ll “work”... but unless the motors are PERFECTLY linked to each other (to prevent drift) it will cause issues for power, efficiency, noise and reliability of the controller.
Look at how a single works before you connect dual motors. The speed control sends pulses for motor to engage rotation, then motor sends back info about its location relative the stator coils. This info tells the speed control when to send next pulse. When you connect another motor you also get another location info about where the motor are. These signal info may collide or create an duplicated info so the speed control send pulse for a double speed that no motor are at. This configuration will never work good.
Lots of interesting comments on what the issue is.
Brushless dc motor controllers need to get feed back from the motor to know the position of the rotor, this feed back is obtained in one of two ways, either from hall sensors or from from the normal voltage generated when a motor is rotating (back emf). When the controller knows the position of the rotor, it then knows when to apply power. The motor has three phases and the controller has to monitor and manage each of them.
When you connect two motors to a controller, it will be getting feedback from both motors and unless they are both phase syncronised (unlikely) they will not run properly as the duel feedback will cause the controller to not correctly apply power to one or both motors.
Dont they just chop the DC ?
@@boingo001 No. If a motor has brushes, they control which coils are getting current, at the correct moment to cause rotation, and the current could then be "chopped", but brushless motors, of course, don't have brushes, so current control through the coils has to be done electronically
@@petertyrrell6690 Yes , sorry missed the brushless wording, sticks out when I read it properly.
I actually thought it would work because the motors are as you said identical. Neet thing to know.
Problem with this is when you load those motors since only one gas feedback loop
The one with open loop can lose its position and it will start to draw huge amount of current without transferring power
And there is a big risk of blowing the motor or controller
What if the motors are physically coupled together so they can't lose sync?
Try some big diodes on teh phase wires to prevent induced currents from one motor screwing with the other.
Great vid, but would be better if you showed how to have them going in different directions like you would on a trike axle
Ur drawing double the current/amps.
You will be able to cook bacon on that speed controller.
That's not how it works, the controller will limit the amps.
Try putting the motors in series. If it runs too slow, increase the battery size 6 volts at a time until it runs correctly.
Jim Rojas I dont think you know how a brushless motor works you cant put them in series its physically impossible due to only been 3 phase s
Series..??? You mean in parallel, yes i know that you can not connect two hub motors in parallel, also i do not recommend that... This video is testing proof for one subscriber..
@@nightmareinaction629 You are correct. I thought they were DC motors. Have you tried putting a run capacitor in between each phase?
No my friend i didn't try it...
Llegaste a probarlo en una bicicleta para ver si el controlador aguanta los dos motores..??
Running these on the same axle will cause all kinds of issues with torque transfer. An equivalent effect being that of wind up in a locked axle on a car going around a corner.
Everytime you turn the wheel you're going to be fighting the motors trying to push the wheels straight again.
Like and old posi unit from in a car.
Would you be able to pick those dual hubs Motors on a trike
The way trikes generally have a rear axel you might be better off with a “mid mount” style motor
Can put these bad boys on an aquarium. Anything really
@@ななころび you can even put them on your face
thanks, one question, this kind of motor does not have hall on it right, but if I have two hall sensored motors I could install it with no problem?
two motors connected in paralel -become motor-generator system with oscilation of mechanical energy between one and another - it cause looses, if they will be on one wheel or even maybe on real cycle - Imho it will fixed by flat and dependent rotation of both motors, without ping-pong energy exchange between motors
Yes, but badly. :P I tried this with a controller with hall sensor support. That particular variant ran faster with hall sensors enabled. So I lost a lot of top speed.
can i ask something, compare 2 controllers 2 bldc with 1 controllers 2 bldc, which is the best? and why?
You're drawing twice the current through one controller rated for one motor(so i can only assume). Once you let the smoke out you can't put it back in (lolz). The moment you try this with a decent load (let's say a go kart) you will draw around 6x the rated current at zero RPM from BOTH motors and things won't end up well. You want two separate power sources and two separate controllers for PWM motor control applications with ONE throttle connected to both PWM CONTROL circuits (in Parallel). This will eliminate any frequency, resistance, and inductance/capacitance differences from interacting with each other through one modulator. Too many factors contribute to imbalances such as different wire length, internal motor winding insulation condition, rolling resistance of bearings inside the motors, defective parts inside of cheap Chinese controllers...all affecting the operation of the capacitors and voltage regulators ect.. inside the controller.
Add for bouth motors, one way diode's and they will work! They act like this because one motor is trying to charge the other one so on....they act like a generator...if they have one way diodes, they will work 100%! Ty !
i think the bad sound his just an acoustic problem of phase, when the 2engine have the same speed, the frequency of sound have an "resonance" called phase, because its the same sound but with a short delay because the distance (of sound captation) is not the same…. if you find the frequency (like wood's frequency for example and try ;-) ) you can maybe erase the noise…. sorry for my poor english
Can you show a wiring for a button that switches between single motor and dual motor without having to unplug the wires like your doing in the video?
It's green signal wire to a positive the same watts. I was trying ground and it kept reading error. Took multimeter, found out the signal is positive and wired it up and works now, so positive to signal will give you your dual or single mode
No loses watt....but paraller 2 motor = look like delta wire
more amp.. you need to drive the motor
Its not simple calculation 22+22= 44
Becouse the resistant wire 1 motor, when you jointed the wire to another motor make it low resistan
If you jointed 2 motor its made more biger induction n more biger back EMF ( mybe not same time back emf betwen 2 motor) make your motor sound like there is the load so more current you need to supplay this motor
I like the build, but let's have some perspective here on the charging.
1,402 comments here, and not one has looked at the maths.
His solar panels added up is less than 2 sq meters.
They look like old technology panels.
Modern panels produce 150 - 200 watts per sq meter.
Let's be generous and say the vehicle can generate 300 watts in full sun.
So 12 hours of full sunshine - could generate 3.6 KW hours
His 2 hub motors will be at least 1,000 watts each.
Assume 50% efficiency for the whole system.
So 12 hours of charging in full sun = 3.6 kWh. (Kilo Watt Hours).
The motors together are 2KW.
With 50% efficiency, a full 12 hours charge gives 3.6 *50% /2 =.72 hours
That equals at best 43 minutes driving time per day.
In practice, I would be impressed if he got 10 minutes driving time from 12 hours of solar panel charging.
I know the motors won't be at full power all of the time, but they do have to push around a lot of metal as well as the driver and passengers.
These motor were designed to drive a pushbike, so will be heavily loaded in this application.
This vehicle will need to be charged by mains or generator to be of any use.
The solar panels can drive electronics - headlights radio etc
In addition, he uses bicycle wheels.
Bicycle wheels are designed for vertical stresses only, no sideward stresses.
He will get away with it for a while by using fat tire wheels because the spokes in the rim are splayed from side to side.
Every time he turns, his wheels endure severe side stresses.
The wheels will buckle in time.
Bicycle wheels are designed to lean when turning, so there are no sideways stresses.
The other problem with this build is the rear differential.
You cannot drive the 2 motors with one controller because the motors will be forces to move at exactly the same speed.
The two rear tires are locked together so when turning these motors will experience severe stress forcing tire skid.
It might work for a while on a dirt road, but on a modern road there would be severe motor stress and tire wear.
In addition, if there is more weight on the back wheels, the steering might not work at all.
The alternative is a controller for each wheel, but that requires a very complex hardware and software management system
Mr Musk, Mercedes, BMW, GM etc can design these systems, but it is not in the scope of a backyard inventor.
Strong sunshine pushes out around 1000 watts per sq meter.
Typically, commercial panels today are about 20% efficient.
Even if we had 100% efficient panels, there is not enough energy from the sun to power a family car by itself.
With extreme engineering - carbon fibre frames, super efficient motors and a vast aero dynamic solar surface with very expensive panels, it is possible to create a vehicle that will carry 1 person in a desert environment with good roads.
There is a biannual race for solar-powered cars which takes place in different deserts around the world since 1987.
In recent years, Darwin to Adelaide in Australia.
en.wikipedia.org/wiki/World_Solar_Challenge#2015
These cars do work entirely on solar power, but are so big in area and so light that they sometimes get blown off the road in windy conditions.
Here is a typical solar car.
pt.m.wikipedia.org/wiki/Ficheiro:Solar_Car_Tokai_Challenger.JPG
Usually, one of the Dutch teams wins but in 2019 they were beaten by the Belgians.
2019's race video.
ruclips.net/video/5KD4QQUUv_w/видео.html
I don’t know 🤷🏾♂️ Electronics that we’ll never went to school for it but I believe it’s because your causing the controller to loose Pressure or in other words it’s compensating 34% in Watts because two motors to that controller is like opening a pipeline twice it’s size all of the sudden. In doing so, to fill the pipe to proper pressure, you would need More Energy...
Another example is
If I have a tank that I can fill in 1 hr with whatever power I have and then out of nowhere, I have to fill TWO tanks in the same time, I would need a pump that can pump twice as much and bigger hose to compensate otherwise it will burst.
So your motor is acting like a BIGGER motor than what it really is to compensate for the load the motors are asking for🤦🏾♂️😎
I do think 🤔 💭 I am making sense here😂😂
I know for sure you can run two Motors and two controllers and two separate throttles from ONE BATTERY 🔋😎 I did that way back in 2011😂
@@batmanofinglewood, how should the battery be for two motors that each have 1000W power?
David depends on how fast you want to go. The more amps, the more Torque. The more Voltage, the more speed. You need a battery that can handle the power the controller draws.
You first have to choose a safe voltage. Most run motors in between 48v-72v. More than likely, you want to get a battery 🔋 capable of 60-80 amperes but get a controller that draws around 60amps to have cushion
@@batmanofinglewood, each motor has a capacity of 48V, if they exceed the voltage of 72V on each motor .. will the engines burn?
David 72v fully charged is 84v. Usually motors run more efficiently with higher voltages. The thing is when you up the voltage, in theory, you must drop the amperes or Vis-a-vis. If not, the motors will heat up much more quickly depends on how much power your draw through the throttle signal. 48v fully charged is 56.6v or 58.4v if you have 14s or higher battery 🔋. So you must connect them to the battery in parallel so the voltages stay the same.
can i use..48v ..controler with two hub 350watt..36v..can speed are increase
0:29 LOL, Looks like a happy face!
The sine waves sent to the motor are affected by the motor itself, power is induced in the wires from the magnets passing the lesser powered coils during the cycle. It become an interference pattern with 2 motors
Great experiment. Maybe have a bigger controller more amps
Thanks, an extra knowledge
Motar kro kia he
can you do one throttle running 2 controllers and one power supply?
That would work.
So what did you do with the other hall sensor wires coming from the other motor? I also imagine both hub motors need to be identical and controller needs to handle double the amps of the motors
Question I am wanting to make a 4 Wheel drive cart with 4 Independent drive hub motors (48v 800w (rated 600w, max current 30A) geared hub motor for electric wheelbarrow) is it possible to have one controller for this?
No way... the best you can do is to find 2 hoverboard controllers which have 2 outputs for a motors each one... but there you must program them first..
2 controllers one throttle innit!
Wish you make a video ebike or escooter seft charging battery system , Please . Thank you.
how can i move it in two directions .... can move forward and can move backward???
The "Strange" noise when both motors are running could be coming from the wood resonating and the fact that the whole setup is screwed to the bench!
This noise came from motors...
Thanks for testing this. I wondered about building a trike with two motors on the rear wheels, but I think it will be problematic regulating the power to each motor in turns, slippery road etc. I suppose a differential would be necessary?
How did you get on with the trike project? It's exactly what I would like to do?
@@timtreffry7718 i have also been working on a trike problem is how to vary power on the real two hub motors on turning or i can be using differential and a bigger motor ,robert murray smith showed a freewheel differential for trike but it cannot be reversed so i was thinking of using two motors front wheel hub motor and rear wheel geared motor on differential. Now , the issue is to control them with a single controller and throttle.
This is sound beautiful
Control individual 2 motors? Left or right? For wheel chair...... thanks