Re: Pole Changing Motors?

--- In CAD_CAM_EDM_DRO@y..., Jon Elson <elson@p...> wrote:

> audiomaker2000 wrote:
>
> > Hey all,
> >
> > I am considering purchasing a Deckel mill on which the controller

is

> > toast (actually almost new, but still toast somehow).
> > The main spindle motor is listed as a 6hp "Pole Changing motor

with

> > brake" in the brochure, which is all the information I have on it.
>
> This sounds like a bad translation, but makes electrical sense.

What WE

> call such a thing is a two-speed motor. These are quite common on
> machines, like most Bridgeports with the 2J head (standard mill with
> variable speed belt drive) are equipped this way.
>
> > Since I'm utterly stupid when it comes to motors and motor

theory, I

> > am wondering what such a motor might be driven by? AC, DC, 1 or 3
> > phase, or perhaps step/direction?
>
> It will be standard 3 phase. If there was an electronic variable

speed

> drive
> in the control, this may still be usable. Otherwise, a 10 Hp VFD

unit might

>
> be picked up on eBay, and could run this machine from single phase
> power, if that is all you have.
>
> > My concern is being able to bypass the original electronics of the
> > machine and still gain control of this motor.
> > Unfortunately I don't have access to the machine before I buy it

and

> > with all this stepper/servo stuff in my head, "pole changing with
> > brake" sounded familiar. Could this be a 6HP stepper, or can you
> > brake (hold) an AC or DC motor electrically?
>
> It probably has a mechanical brake for tool changes, etc. No

telling

> whether
> it is electrical or air operated until you see the machine. Most

VFD's can

> brake 3-phase motors to nearly zero RPM, saving wear on the friction
> brake.
>
> > What is the "usual" current or signal type for a braking, pole
> > changing motor of this HP?
>
> The VFD may take 4-20 mA or 0 to +10 V DC. if a late model

control, it

> may be CAN bus or some other industrial network protocol.
> The brake and motor speed change would likely be controlled through
> relays, and maybe a solenoid valve for air operated brakes.
>
> Jon

Thanks Jon, what I am getting is that it would be a standard 3 phase
AC motor? I have 3 phase in my shop already. I was mostly concerned
that it might be a DC motor similar in design to a stepper (pole
changing) and that the brake might be electric (as in "holding").
A 3 phase AC via VFD or Spindle Drive, I can deal with.
As long as I know that AC and "pole changing" can go together, I'm
alright.

Thanks
Sean