Re: [CAD_CAM_EDM_DRO] Home shop power for a big machine

Hi

Surely? if you use an inverter in line with the motor, you could limit it to
say 20A(or whatever you have). Then the motor will ramp up much slower than
usual. By setting the ramp profiles correctly, i think it would work. The
inverter will also be useful in the CNC environment, since the start/stop
will be a signal line.
The real issue is whether the motor would reach desired speed without
overheating, especially if there is a large gearbox load.

Otherwise a cheaper, softstart might work.

Regards
Roland



2008/12/31 Jim Fleig - CNC Services <jim@...>

> Hi Roger,
>
> Just a thought: the power you may need to run the machine may be much lower
> than the power you will need to start the machine. Most three phase motors
> have a surge of power that starts the motor and then the current draw drops
> way down while the motor runs at its rated rpm. It may be more helpful to
> try to address the question about starting the machine. After the machine is
> started, then it may take very little power to run the machine to do what
> you would like to accomplish.
>
> Happy New Year!
>
> Jim Fleig
> CNC Services
>
> machine tool service from casting to control
>
>
> ----- Original Message -----
> From: vrsculptor
> To: CAD_CAM_EDM_DRO@yahoogroups.com <CAD_CAM_EDM_DRO%40yahoogroups.com>
> Sent: Wednesday, December 31, 2008 10:10 AM
> Subject: [CAD_CAM_EDM_DRO] Home shop power for a big machine
>
> I was lusting over a big VMC that would never fit in my home shop and
> got to wondering about power. The machine's data plate says 230 volts
> 3PH @ 80 AMP's, 18KVA. It has a 15 HP spindle.
>
> I could use a rotary phase converter to generate the three phase but
> don't have anywhere near 80 AMP's available. 18KVA/750 watts equals a
> 24 HP phase converter.
>
> If you where using this machine in a hobby environment and not trying
> to get production feeds and loads how small of a phase converter could
> you get by with?
>
> Roger
>
> [Non-text portions of this message have been removed]
>
>
>

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