Re: Running a Bridgeport Interact 1 Mk1 on single phase 240v

Graham,

Why don't you just phone your local electric provider and ask for
three-phase? They are obligated to provide power (at least here in
the UK..) and sometimes will do installation for free, or very
little. Certainly a lot less cost than trying to find a 3KW inverter!

It seems a lot-less hassle than running into blown fuses, invertors
and replacing circuits when you find your current wiring can't carry
all of the load...

(We recently got 3-phase power in the server room at my work, and it
didn't cost us a penny for installation...)

~Abby

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "dgsutton2000"
<dgsutton2000@y...> wrote:

> I am thinking of getting an old Bridgeport Interact 1 with a TNC

145

> control because the machine is like new. I want to run it on

single

> phase and use the 145 control because it will do want I want for

now

> and I'm used to Heidenhein, later on I will be converting it to PC
> control which thanks to other members of this group I know which
> direction to go in however that will still be single phase.
> So for now I want to power the machine from UK single phase 240v.

To

> start off I was thinking of powering the main motor with an ABS
> single phase to 3 phase controller which will allow me to also
> inject D/C to spindle stop. This will draw 18A max 7A normal and
> allow me to program soft start to keep big current drains off my
> single phase supply, this I'll use anyway PC or TNC ....unless any
> one can see a problem here?
> I then need to power up the servo and TNC unit. The TNC is no
> problem I'll just fit another small transformer but the servos are
> fed from a big 3KVA transformer that's wired across 2 of the 420v
> phases. What I was hoping to do was get the transformer rewound to
> feed in single phase and output the correct voltages of 180-0-180-
> 380 to the chokes and drive boards. But I guess this is not that
> simple because I am dealing with what was supposed to be 2 phases
> that are 120 deg apart and my new single phase transformer will not
> give me the same wave form so will interact differently with the
> chokes, anyone any experiance of this? I feel I'm digging myself a
> big hole to fall into, maybe this is why everyone just junks the

lot

> and fit's Gekos etc. Should I try this route?
>
> My other option is to power the machine from a rotary transformer

as

> its commonly known, I've found this company www.isomatic.co.uk
> who could do a unit and I would be tempted to fit a soft start unit
> to the spindle motor to reduce my current spikes then I looked at
> the price of the soft start units and the full motor speed
> controller is not much more so I'd probably fit the full controler
> which means I can now power the motor from single phase agian. So
> all I want this rotary transformer for is to get 2 phases for my
> servos transformer.. It seems crazey to go to this length just to
> power the servos. How else could I power the servos form single
> phase?
>
> I'm really only going to cut alloy at low feed rates so all this is
> getting complicated, any suggestions?
>
> Graham