Has anyone heard of someone successfully using an arduino microprocessor with a 3 phase bldc washing machine motor to power a project? It seems like it would be pretty complicated to set up but the efficiency gains would be outrageous. Just curious.
Drum motors
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anickode
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Brushless DC motors are really 3 phase AC motors. A large enough brushless controller might be able to run it just fine, apart from maybe the voltage issue.
Nope, since the idea isn't going to work..
if there even is such BLDC washing machine motor!
first: a washing machine motor is typically in the low hundreds of Watts
(no more than 250 watts perhaps)
second: a washing machine motor (most likely a universal motor anyways) typically runs at high voltages (220'ish in my part of the world, 110 in yours)
which leads us to the last point: since you cannot force more currents through the coils it significantly looses power if ran at a lower voltage.
And the misconception of a BLDC being nothing bu an 3phase AC motor is fairly common,
but it's simply false!
3Phase AC is typically sinusoidial crosswave
BLDC is a square single wave (only one phase errected at any given time)
true, a BLDC typically has three phases, and it's also true that each of these phases swap direction once per rotation..
Still.. the controllers are WAY different and you will not succeed in trying to run a BLDC off an AC controller (variacs)
nor will you have much fun in running a 3phase AC motor off a BLDC controller.
Anyways.. washing machine motors are the least practical motors to power anything that needs significant power (karts, minibikes so forth)!
heck even a mediocre quality cordless drill has more power at a more usable voltage than a washing machine motor.
'sid
bldc
These are definitely not 3 phase AC motors. They are actual bldc motors which run at low voltages and high torque. The control and efficiency of these motors are incredible but I've yet to see an actual project powered by one because the engineering and electronic requirements are much steeper than a brushed motor.
Heres the patent for a bldc washing machine motor
https://patents.google.com/patent/US7042120B2/en
youtube video of a motor being run at 12v with an esc. He say the torque is huge
https://www.youtube.com/watch?v=cmzQiG-z3jc
Here is a guy who has managed to get one running on a single transistor at 12 vdc
https://www.youtube.com/watch?v=11vjLOe6V3c
They are very high torque motors as they are usually direct drive and must push heavy loads of wet laundry. People are saying they would make good project motors and One guy was running one with 120a esc at 24volts. They are also extremely efficient and low noise. My feelings are that with an arduino coordinating the 3phases through power transistors might make a very nice motor for a project.
These are definitely not 3 phase AC motors. They are actual bldc motors which run at low voltages and high torque. The control and efficiency of these motors are incredible but I've yet to see an actual project powered by one because the engineering and electronic requirements are much steeper than a brushed motor.
Heres the patent for a bldc washing machine motor
https://patents.google.com/patent/US7042120B2/en
youtube video of a motor being run at 12v with an esc. He say the torque is huge
https://www.youtube.com/watch?v=cmzQiG-z3jc
Here is a guy who has managed to get one running on a single transistor at 12 vdc
https://www.youtube.com/watch?v=11vjLOe6V3c
They are very high torque motors as they are usually direct drive and must push heavy loads of wet laundry. People are saying they would make good project motors and One guy was running one with 120a esc at 24volts. They are also extremely efficient and low noise. My feelings are that with an arduino coordinating the 3phases through power transistors might make a very nice motor for a project.
I never said a washing machine had a 3phase AC motor in it (since that'd be stupid really)
I said people mistake BLDC for 3phase AC since their layout is fairly similar to the untrained eye.
never seen such LG motor.. impressive..
never seen a direct drive washing machine at all
(the ones I popped open were belt driven universal motors)
Anyways, true a direct drive motor like that should have a serious amount of torque.
but I need numbers not feelings to estimate the use of it.
Since we don't know the project you're aiming for, we are unable to even make an assumption if it's of use for that.
But I'll stick with: "likely not worth the hassle if you're trying to power a personal vehicle with it" (aka kart or mini bike likely not going to happen... powered kick scooter maybe but it seems to be too large to not look ridiculous on a kickscooter or skateboard)
I'd still say the motors run on high voltages and rather low Amps (wich makes it loose it's potential if ran at lower voltages)
since frankly a transformer is expensive,
a simple rectifier circuit is much cheaper and likely more reliable as well
(for sure more reliable than a switch mode power supply)
PLUS: Wesley (the first video guy) stated that he had to rewind the motor.
(assuming in order for it to run @12V ?)
An arduino could switch a series of MosFETs of course, but WHY?
it's overkill in one way
you cannot make use of most of an arduinos capabilities since it can't multitask
and you wouldn't want to halt the motor to switch, trigger or adjust anything but the motor speed.
and undersized in other ways
20mA per output is okay, but not exactly something to write home about.
you might even need to beef that up in order to trigger the gates of a powerfull MosFET.
In fact you'd even have to delay the phase switching in order to read the throttle position
and adjust the speed accordingly.
Personally, since you sholdn't air wire the MosFETS anyways especially since you need to cope with backEMF
(reads: at least add diodes to cut reverse currents off, and thus will have to make a pcb for mosfets and diodes)
ideally you want the backEMF to tell motor speed and shaft orientation in order to correctly switch phases.. otherwise the motor will not run well at all under load.
you'd better get a dedicated ESC and control it with the arduinos PWM signal line instead.
it does all the back EMF trickery for you right off the shelf
that way you can also make use of the arduinos capabilities better since you don't need to toggle it's outputs but instead you just set it and leave it until changed
while doing other stuff (quasi multitasking)
'sid
I said people mistake BLDC for 3phase AC since their layout is fairly similar to the untrained eye.
never seen such LG motor.. impressive..
never seen a direct drive washing machine at all
(the ones I popped open were belt driven universal motors)
Anyways, true a direct drive motor like that should have a serious amount of torque.
but I need numbers not feelings to estimate the use of it.
Since we don't know the project you're aiming for, we are unable to even make an assumption if it's of use for that.
But I'll stick with: "likely not worth the hassle if you're trying to power a personal vehicle with it" (aka kart or mini bike likely not going to happen... powered kick scooter maybe but it seems to be too large to not look ridiculous on a kickscooter or skateboard)
I'd still say the motors run on high voltages and rather low Amps (wich makes it loose it's potential if ran at lower voltages)
since frankly a transformer is expensive,
a simple rectifier circuit is much cheaper and likely more reliable as well
(for sure more reliable than a switch mode power supply)
PLUS: Wesley (the first video guy) stated that he had to rewind the motor.
(assuming in order for it to run @12V ?)
An arduino could switch a series of MosFETs of course, but WHY?
it's overkill in one way
you cannot make use of most of an arduinos capabilities since it can't multitask
and you wouldn't want to halt the motor to switch, trigger or adjust anything but the motor speed.
and undersized in other ways
20mA per output is okay, but not exactly something to write home about.
you might even need to beef that up in order to trigger the gates of a powerfull MosFET.
In fact you'd even have to delay the phase switching in order to read the throttle position
and adjust the speed accordingly.
Personally, since you sholdn't air wire the MosFETS anyways especially since you need to cope with backEMF
(reads: at least add diodes to cut reverse currents off, and thus will have to make a pcb for mosfets and diodes)
ideally you want the backEMF to tell motor speed and shaft orientation in order to correctly switch phases.. otherwise the motor will not run well at all under load.
you'd better get a dedicated ESC and control it with the arduinos PWM signal line instead.
it does all the back EMF trickery for you right off the shelf
that way you can also make use of the arduinos capabilities better since you don't need to toggle it's outputs but instead you just set it and leave it until changed
while doing other stuff (quasi multitasking)
'sid
mckutzy
Well-known member
Hehehe.
He said mediocre.....
Every time I hear this I think back to.. he who said it best...
Imortan Joe....
https://m.youtube.com/watch?v=HnNPxF5jj9Y
itsid said:
I think you may be right on this. Since the phase voltages are pulsed rather than continuous I would think think the amperage could be much higher than a motor with similar gauge stator coils using a continuous sine wave for the phases. As I said this is directly coupled to a bin meant to push full loads of wet laundry so the torque has to be pretty high but I'm having trouble finding any numbers for the motor. I think another problem might be coupling it to a drive wheel. Thanks for taking a look though. I'm hoping this technology really takes off as it has so much potential.
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serious misconception!
the overall currrent per 60° turn (on phase one direction of voltage)
is nearly identical..
in fact since the sinusoidial is "more graceful" than a square wave,
it might even allow for a slightly higher current
(although NOT at it's peak voltage and thus at a lower power ratio)
But thinking about that is pointless...
you can imagine a lot of things -as many as you like really-
the laws of physics will not care and cannot be broken.
And in the end, the motor is the one that dictates how much current is able to pass (depending on magnetic field strength of both, stator and rotor, coil wire gauge, temperature of the armature and lastly friction)
if you don't have a schematic of such washing machine, and no manufacturer documentation of the motor there is one single way to find out the motors capabilities.
TEST IT!!
OH.. one more thing:
the motor is NOT PUSHING anything!!
it's rotating stuff around!
what's the difference?
well, take a car wheel, lay it flat on the ground and push it 10ft...
now have it stand up and roll it back the 10ft ..
see? same weight, same distance much different amount of effort
and while that is not a 100% accurate analogy.. it's still the same principle.
(rolling resistance vs sliding resistance.. that's why clothes in the washing machine tumble around, because that takes less effort than sliding along the dimpled wall
)'sid
PS something boggles me.. since it's a direct drive the motor is cooled by the drum and essentially the water IN the washing machine ...
How much of that cooling effect is necessary to not burn out the motor in free air *shrugs* ... any longevity tests on YT?
You sound like you know what youre talking about so I'll defer to you but I was thinking about the difference between a class A Amplifier and a Class B amp is that the class B can drive more power because one of the transistors is always cooling off. It seems like the coils in a bldc should be able to take more current because they are able to cool during the off Phase.itsid said:
[quote="itsid]
OH.. one more thing:
the motor is NOT PUSHING anything!!
it's rotating stuff around!
what's the difference?
well, take a car wheel, lay it flat on the ground and push it 10ft...
now have it stand up and roll it back the 10ft ..
see? same weight, same distance much different amount of effort [/quote]
Very nice explanation!
[quote="itsid]PS something boggles me.. since it's a direct drive the motor is cooled by the drum and essentially the water IN the washing machine ...
How much of that cooling effect is necessary to not burn out the motor in free air [/quote]
I'm not sure I understand your question. Its a direct drive motor but the water in the machine has no cooling effect on the motor. Its coupled to the drum by a small shaft and stays completely dry, If I'm understanding the question right.
Thanks for all the technical help. Its hard to get a handle on all the details.If I can find any numbers I'll post. If one can get over the hurdles the motor presents It has a lot of advantages to it.
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please use the quote brackets it makes reading much easier...
-I've added them to your posts, click on the edit button to see how they work.-
(lower left of each post is a quote button that conveniently does that for you)
true, the coils have an off phase, but consider that below a certain level
of power the sinusoidial transition towards it's peaks doesn't add heat to the coils either.
And the square wave will be above such threshhold during it's on-phase at all times.
So the overall induced heat will be fairly identical.
You know the fancy growing garden hoses that stretch and widen when filled with water?
you can dripple water through without them stretching.
likewise you can run (a low enough amount of) power through a large enough wire indefinetly without it heating up and if it was heated before it can even drop it's temperature with ambient cooling again.
Now cooling...
I was maybe misleadingly using drum as a term,
but a washing machine has two nested drums inside, the inner one rotates, the outer one is fixed to the chassis.
I misinterpreted the "mounting bracket" as the back half of the outer drum (or tub).
That bracket, holds the rotor bearings and even protrudes into the stator housing with further protrusions which I would identify as cooling fins.
Allow me to color it magenta in the patents depiction:
as you can see the stator housing is directly mounted to said bracket
Since all motor produce heat,
that large metal structure should be a welcome "heatsink"
Just as you mount your transistors to the controller case
for it acting as a heatsink.
And that part also sits below the water line (another colored patent depiction)
And since it has what appears to be more cooling fins on the lower back side...
I cannot imagine it NOT also being a heatsink for the motor.
Might be a misinterpretation on my behalf, that's why I asked if there are any longevity test of that motor without it being installed to it's washing machine.
'sid
PS If you do not already have such motor laying around, I still say it's not worth the hassle.
there are smaller more powerfull options out there that are likely easier to get hold of too
-I've added them to your posts, click on the edit button to see how they work.-
(lower left of each post is a quote button that conveniently does that for you
)true, the coils have an off phase, but consider that below a certain level
of power the sinusoidial transition towards it's peaks doesn't add heat to the coils either.
And the square wave will be above such threshhold during it's on-phase at all times.
So the overall induced heat will be fairly identical.
You know the fancy growing garden hoses that stretch and widen when filled with water?
you can dripple water through without them stretching.
likewise you can run (a low enough amount of) power through a large enough wire indefinetly without it heating up and if it was heated before it can even drop it's temperature with ambient cooling again.
Now cooling...
I was maybe misleadingly using drum as a term,
but a washing machine has two nested drums inside, the inner one rotates, the outer one is fixed to the chassis.
I misinterpreted the "mounting bracket" as the back half of the outer drum (or tub).
That bracket, holds the rotor bearings and even protrudes into the stator housing with further protrusions which I would identify as cooling fins.
Allow me to color it magenta in the patents depiction:
as you can see the stator housing is directly mounted to said bracket
Since all motor produce heat,
that large metal structure should be a welcome "heatsink"
Just as you mount your transistors to the controller case
for it acting as a heatsink.
And that part also sits below the water line (another colored patent depiction)
And since it has what appears to be more cooling fins on the lower back side...
I cannot imagine it NOT also being a heatsink for the motor.
Might be a misinterpretation on my behalf, that's why I asked if there are any longevity test of that motor without it being installed to it's washing machine.
'sid
PS If you do not already have such motor laying around, I still say it's not worth the hassle.
there are smaller more powerfull options out there that are likely easier to get hold of too
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