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Not Like Mom's Old Washer

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  • J Tiers
    replied
    Originally posted by MaxHeadRoom View Post
    I have been trying to get my hands on one for experimental purposes, I am surprised that someone has not put a circuit out there, (maybe they have already) likewise the ECM motors used now in HVAC systems, motors are being scrapped, I know it!!
    Max.
    Yep, the cheapo inverters that go with will die, and the motor is fine. Theoretically just the inverter can be replaced, but many don't mess with it, on the theory that both might be bad, and they don;t want the risk.

    I have one or two, but have not done anything special with them yet.

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  • The Artful Bodger
    replied
    Originally posted by MaxHeadRoom View Post
    I have been trying to get my hands on one for experimental purposes, I am surprised that someone has not put a circuit out there, (maybe they have already) likewise the ECM motors used now in HVAC systems, motors are being scrapped, I know it!!
    Max.
    I have several of those motors and would gladly send you one but it would be darn near cheaper for you to buy a new machine than what it would cost for me to courier one!

    If you want to read about the [email protected] motors try this site http://www.thebackshed.com/forum/home.asp [email protected] motors are very old hat here now having been introduced in 1990 so the activity on that site has died off somewhat, just search for [email protected] and you will see a hundred or so topics on that site.

    John

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  • MaxHeadRoom
    replied
    Originally posted by The Artful Bodger View Post
    Cogging is an issue with some applications of the Fisher and Paykel motors but it can be reduced by rounding the tops of the stator poles. .
    I have been trying to get my hands on one for experimental purposes, I am surprised that someone has not put a circuit out there, (maybe they have already) likewise the ECM motors used now in HVAC systems, motors are being scrapped, I know it!!
    Max.

    Leave a comment:


  • The Artful Bodger
    replied
    Originally posted by MaxHeadRoom View Post
    These drives when used open loop tend to exhibit 'cogging' at low rpm when used on their own, it requires the tight PID loop to control them to the fine resolution required of a CNC machine.
    Max.
    Cogging is an issue with some applications of the Fisher and Paykel motors but it can be reduced by rounding the tops of the stator poles. This is easily done with a file or suitable power tool.

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  • MaxHeadRoom
    replied
    I use BLDC servos with the more recent encoder commutation tracks that have replaced the old Hall effect. (They perform the same function).
    The Fanuc AC servo's that I converted I also use for spindle control, this way they can be used for C axis positioning.
    The motor I tried on a VFD was a PM AC servo and it did not perform satisfactorily at all.
    BTW the BLDC servo drives I use do not position per-se, they are simple torque mode (transconductance) amplifiers, the positioning is done with the encoder loop back to the motion controller.
    These drives when used open loop tend to exhibit 'cogging' at low rpm when used on their own, it requires the tight PID loop to control them to the fine resolution required of a CNC machine.
    Max.
    Last edited by MaxHeadRoom; 08-30-2017, 04:23 PM.

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  • J Tiers
    replied
    Originally posted by MaxHeadRoom View Post
    Thats what I said. They are only different in commutation, this pertains to my experience with servo's of both types..
    I have ran both types in both modes, the (Fanuc) AC servo to BLDC version required an encoder with commutation tracks.
    Apart from commutation they are identical, in the case of AC the rotor magnets had an arced top to them, otherwise no difference physically .
    Max.
    BLDC with the electronics package (not servos) often have commutation via hall effect sensors. That's "motors". Servos are another matter, they may have all sorts of interfaces that allow absolute positioning, etc.

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  • MaxHeadRoom
    replied
    Originally posted by J Tiers View Post

    PMAC and BLDC are not the same thing, even though they can look similar.
    Thats what I said. They are only different in commutation, this pertains to my experience with servo's of both types..
    I have ran both types in both modes, the (Fanuc) AC servo to BLDC version required an encoder with commutation tracks.
    Apart from commutation they are identical, in the case of AC the rotor magnets had an arced top to them, otherwise no difference physically .
    Max.
    Last edited by MaxHeadRoom; 08-30-2017, 02:41 PM.

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  • J Tiers
    replied
    Originally posted by MaxHeadRoom View Post
    The other differences between the BLDC and 3 phase P.M. models is in the commutation, outwardly they look exactly identical, the BLDC has only two winding's energized at any one time, Essentially a DC motor turned inside out, the 3 phase version is just that, all three winding's fed.
    I have tried them on a VFD with very poor results, Hitachi claim they can do it but require a customized version.
    Max.
    Several manufacturers make VFDs that will run a "PMAC" motor very well indeed, I have done a little with them. (PMAC=Permanent Magnet Alternating Current)

    PMAC and BLDC are not the same thing, even though they can look similar.

    Leave a comment:


  • MaxHeadRoom
    replied
    The other differences between the BLDC and 3 phase P.M. models is in the commutation, outwardly they look exactly identical, the BLDC has only two winding's energized at any one time, Essentially a DC motor turned inside out, the 3 phase version is just that, all three winding's fed.
    I have tried them on a VFD with very poor results, Hitachi claim they can do it but require a customized version.
    Max.

    Leave a comment:


  • MattiJ
    replied
    Originally posted by Noitoen View Post
    Every VFD operated motor is run on DC power (converted from AC to DC and back to 3 phase AC by the VFD) and could be battery operated provided you have the correct voltage. All our battery forklifts have 3 Phase AC drives. The only difference is that asynchronous motors are like out regular motors have a squirrel cage rotor and run at slightly less speed than the synchronous speed because of the need to induce the magnetic field on the rotor and the synchronous motor with the magnetic rotor.
    Some of the difference is that some motors are optimized for trapezoidal waveform, not sine wave.
    BLDC (brushless DC) refers usually to that variety even if its basically permanent magnet synchronous motor.
    PMSM usually refers to sinewave-fed permanent magnet synchronous motors.

    http://www.motioncontroltips.com/faq...idal-back-emf/

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  • Noitoen
    replied
    Every VFD operated motor is run on DC power (converted from AC to DC and back to 3 phase AC by the VFD) and could be battery operated provided you have the correct voltage. All our battery forklifts have 3 Phase AC drives. The only difference is that asynchronous motors are like out regular motors have a squirrel cage rotor and run at slightly less speed than the synchronous speed because of the need to induce the magnetic field on the rotor and the synchronous motor with the magnetic rotor.
    New motors however play around with different stator/rotor pole combination and achieve a kind of magnetic gear box. The 12/14 pole combination has a natural 7 to 1 reduction. To operate these motors in a more efficient way, usually some kind of position sensing is used mainly to aid quick start and direction change opperations.

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  • The Artful Bodger
    replied
    Originally posted by Bob La Londe View Post
    That's a totally different motor. More of a 3 phase brushless permanent magnet DC hub motor. I skimmed over several of those in my reading today. Its kind of an odd duck to me. I think its used as a direct drive in the washer it came out of too.

    This is a permanent magnet motor like that in the Fisher and Paykel. Plenty of arguments on-line as to whether it is an AC or DC motor but whatever it also operates quite well as a 3 phase alternator and as a three phase stepper.

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  • Bob La Londe
    replied
    Originally posted by skunkworks View Post
    He is thinking of using it for a direct drive lathe spindle... (Large center hole)

    https://youtu.be/2HdikHRXnAs
    That's a totally different motor. More of a 3 phase brushless permanent magnet DC hub motor. I skimmed over several of those in my reading today. Its kind of an odd duck to me. I think its used as a direct drive in the washer it came out of too.

    I don't really know what I plan to use this 3 phase AC induction motor for. I already have a complete AC servo motor and drive for the spindle of the little lathe I am converting to CNC.

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  • skunkworks
    replied
    He is thinking of using it for a direct drive lathe spindle... (Large center hole)

    https://youtu.be/2HdikHRXnAs

    Leave a comment:


  • Bob La Londe
    replied
    Well, after much research it seems to be a half duplex RS232 data signal. I can setup a halfduplex/fullduplex adapter and analyze the data to find a way to control the controller or I can just buy a VFD from Driveswarehouse and ask the guys there to help me set it up if I run into trouble. I've already spent way more time than I should have researching this. At first glance it looked like a nice controller, but I might be better off selling the controller on Fleabay to somebody who wants it to fix their washer and using that to defray the cost of a regular more universal VFD to run the motor. LOL.

    So... after spending a couple hours tearing apart the machine and half a day researching the controller, I salvaged a motor, a couple modestly heavy tension springs, and a very light gage stainless steel tub. I should have just made parts and bought a brand new motor and controller. I'd be money ahead. LOL.


    ... and I still have to clean up the mess in the shop.



    ...

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