Re: [CAD_CAM_EDM_DRO] Servo as Lathe Spindle Motor

Hugh Smith wrote:

>
> Would it be possible to use one of your Geko 3xx drivers
> to run a 2 HP servo motor as a lathe spindle?

Yes, if you can find a 90VDC 2HP motor. Such a motor
would run at (less than 80 volts, to be safe say 75 volts
for the G320/G340) and 20 amps (the upper limit of the G320/G340).

I have experience with Leeson 90VDC motors, and the highest HP
90VDC motor I know of is 1 HP at 10 amps (actually there are
two varieties: a 90VDC 10A @ 2500 rpm weighing 34 pounds, and
a 90VDC 10A @ 1750 rpm weighing 40 lbs).

To give some other Leeson motor comparisons:
- A 2HP 180VDC motor (51 pounds) draws 8.6 amps, but if
you only feed it 75 volts, you are back under 1 HP

- A 3 HP 180VDC motor (89 pounds, 1750 rpm) draws 14 amps,
but if you only feed it 75 volts, you might get 1.5 HP,
but at speeds less than 730 rpm). Slower speeds than
that give less HP, and may be rough on the motor because
it is being operated so far from its design point. Motors
this big are rather pricey at their list price: $1641 ea

- A 2HP 24VDC motor (43 pounds) draws 78 amps, but if
you only feed it 20 amps, you have less than 1/2 HP.

No doubt some other manufacturer has a 90VDC 2HP motor...
you just have to find it.

As for part 2 of your questions (direct driving the error
signal on the Gecko)... you'll have to ask Mariss.

Doug Fortune
http://www.cncKITS.com