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  1. #1
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    Feb 2018
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    BF20 G0704 Spindle control

    Hi
    I have been converting a BF20 mill, all going well except for spindle control.
    I have a PDF from simplex motion https://www.simplexmotion.com/docume...ersion_01b.pdf
    about using the existing speed controller inside the white control box, however, things are not the same inside my machine and I wonder if there is a better way.
    The simplex motion instructions say to tap into the potentiometer wires for the 0-10v reference. However, my potentiometer has about 100v running through it and it seems it is meant to be that way.
    So playing around with these wires and plugging them into a BOB is a bit of a problem.

    So, what are my other solutions?

    thanks in advance
    Patrick

  2. #2

    Re: BF20 G0704 Spindle control

    I think the most common solution is to ditch the stock motor and control and just use something with VFD. It's way more expensive, but the stock motors aren't great anyways.

  3. #3
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    Feb 2018
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    Re: BF20 G0704 Spindle control

    Quote Originally Posted by CL_MotoTech View Post
    I think the most common solution is to ditch the stock motor and control and just use something with VFD. It's way more expensive, but the stock motors aren't great anyways.
    OK, thanks, is there any popular motors & VFDs?
    I'm assuming this also means changing over to belt drive?

    Thanks

  4. #4
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    Re: BF20 G0704 Spindle control

    I think I'm about to pull the trigger on a 3 phase AC motor/VFD combo. For a really long time I tried to get a 1HP servo motor to work but I've never been able to get it to work or tuned properly so I think it's time to move onto the next thing.

    I'm likely going to follow this thread: https://www.cnczone.com/forums/bench...formation.html and will probably end up with the Y366 motor. I haven't decided on the VFD yet but I have a feeling I'll probably end up buying the one listed in the thread since I know someone has at least used it successfully.

    I already have a belt drive setup but I'll most likely be switching to a 1:2 pulley ratio to get up to 7200 RPM (I think that's the highest with that motor and VFD combo) and call it a day. I don't remember RPM the bearings I swapped to awhile back are rated for, but if 7200RPM is too much, I suppose I'll find out.

  5. #5
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    Re: BF20 G0704 Spindle control

    I've got a similar machine.
    I've bought a Lichuan 1.8kw 3000rpm servo system for it.
    It's stock belt driven already but there's not much I can do with the puuleys.
    So. I'm taking a punt with a large 112mm pulley on the motor to give a max of around 5600rpm. (motor is only 110mm square itself).

    (that's if I ever get round to installing it all)

  6. #6
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    Jul 2016
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    55

    Re: BF20 G0704 Spindle control

    I have the lichaun 1.8kw servo motor and a 2:1 pulley. It's a great setup but it gets pricey to convert.

    Back to the original question about control of the stock motor. Where are you measuring for the voltage? 100v isn't right. Open up the control box, any labels on the control board? It should be some sort of KB knock off board.

  7. #7
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    Re: BF20 G0704 Spindle control

    Quote Originally Posted by DJEkim33 View Post
    I have the lichaun 1.8kw servo motor and a 2:1 pulley. It's a great setup but it gets pricey to convert.

    Back to the original question about control of the stock motor. Where are you measuring for the voltage? 100v isn't right. Open up the control box, any labels on the control board? It should be some sort of KB knock off board.

    Only thing I can find is this info below using one of those £6 Chinese boards that I also use.
    Shows relay outputs to the CSK / GND pins.
    Shows 0-10v out and gnd to INPUT / GND pins.
    You get a better image when downloaded as a pdf.

    I don't really trust these things you find sometimes and didn't want to risk it hence the servo.
    Probe the heck out of the pot / pins if you're adamant on trying it.

    No liability from me. I didn't even try.

    https://designconceptschi.wordpress....indle-control/


    Also came across this kb board schematic:
    https://acim.nidec.com/drives/kbelec...ual.ashx?la=en
    Looks like the 0-10v would be to do with either of pins 1,2 or3 with relay on I1,I2.

    At your own risk.
    If the pot measures more than 12vdc, forget it.

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