Re: Converter or Inverter for 2hp Bridgeport mill

In parallel to John's question, I'd like to know about setting the
spindle/motor ratio on my varispeed BP also, so that I can control
the speed via the VFD. Does anyone have experience doing this? Any
caveats?
-Lee

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Lee Studley"
<indigo_red@q...> wrote:

> VFD's are great!!
> I think most VFD's have reversing builtin(?). Having a switch

break

> connections from the VFD to the motor doens't sound good to me. If
> you want to keep the mechanics of the original Fwd/Rev switch, I
> would suggest wiring it as a switch to control the VFD's external
> fwd/rev option if it can be done as an external control.
>
> -Lee JMO-ICBW:-)
>
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "john_glynn57"
> <john_glynn57@y...> wrote:
> > I have just taken delivery of my own Bridgeport mill and want to
> > know which is the best option for powering the machine : an
> inverter
> > or a converter.
> > My research to date suggests that a Hitachi L100 inverter is the
> way
> > to go however I want to question this as follows:
> > 1. I can run a dedicated 20A or 30A supply to the machine which
> > should be able to handle the startup current demand of a

converter.

> > 2. If I use a converter I can use all the original Bridgeport
> > systems without mosification ie Bridgeport speed control,forward
> and
> > reverse,3phase coolant pump and shaping unit which is attached

to

> > the machine.
> >
> > My plan is to circumvent the original Bridgeport wiring and

drive

> > the Main motor(s) directly from the hitachi unit and setting the
> > motor speed at the low speed of 1400 and not using the valiable
> > speed control of the machine at all. The hitachi will give me
> speed
> > control by varying the frequency however I do intend to use the
> > original forward reverse switch. In addition I plan to replace

the

> > coolant motor with a single phase model.
> >
> > Am I doing the right thing.