Re: [CAD_CAM_EDM_DRO] high frequency spindle motors

Bob Simon wrote:

>Here are the list prices for the AC Tech VFD. The man-rep mentioned that
>most distributors discount the price somewhat.
>
>2HP 208-240 volt (200V class) with 1000Hz option $339.00 Mod. # SF220-V
>
>

Not bad, for what it does! At some time, I will have to get one of
these! Does this price
include the programming keypad? How about analog speed input (for
direct CNC control?)
I guess I'll have to read the manual to find out which features are
stock, which are add-on
options.

>5HP 208-240 (200V class) with 1000Hz option $497.00 Mod. # 250-V
>
>

A bit higher, but definitely better than I had feared, for a "special"
model.

Remember to specify for the line current the motor draws, rather than HP
rating, as these are
NOT plain 220 V motors.

>The rep recommended using a line reactor on the input side to smooth out
>transients and ac harmonics. I have several abandoned high current 220 volt
>taps available on my machine tool's isolation transformer after switching
>to a 120 volt (170vdc) servo system. The rep said using one of these taps
>would be a very adequate substitute for the input reactor.
>
>

Maybe that will work, but it could put all sorts of trash into the CNC
system.

I have some small power-input filter modules that I put in the input to
the VFD after it caused
trouble with my computer-controlled air compressor. It didn't bother my
CNC system, except
for putting a little fuzz on the CRT screen.

Thanks for the research!

Jon