Re: [CAD_CAM_EDM_DRO] Re: Plasma table gear reduction

Every thing will be (mostly) liner but you have three
factors, I=torque, V=rpm (kinda), power = I x V
(kinda). 2 of these factors multiply so if one factor
changes the result changes proportionally. so... the
assumption that the current would be 1/3? is wrong,
because 1/3V(rpm) * (full)I = 1/3HP

the motor 90v 3000rpm 3/4 horsepower will only operate
at 1/3 hp at 30v and 1000 rpm with full current. this
will produce the same heating factor of the motor. if
the motor has a shaft mounted fan it will be running
at 1/3 the rpm and you should consider using
independant fan for cooling. with the right fan the
motor will received almost the same cooling as with
the shaft mounted fan.


--- "Roy J. Tellason" <rtellason@...> wrote:

>
> On Monday 20 December 2004 12:13 pm, turbulatordude
> wrote:
>
> > As for the de-rating. As it appears to me, a
> 3/4hp dc motor at 90
> > volts would be something like a 1/4 hp at 30 volts
> ? That 3,000 rpm
> > would then be 1,000 rpm (still shakey on this
> after reading notes on
> > DC motors)
> >
> > So, the motor range would be from zero to 1,000
> RPM. and 0-30 volts.
>
> I'm wondering if this stuff would really be as
> linear as all that...
>
>
>
>
>
>
>
>
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