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Since I think I have the x,y,z servo solution
worked out for my Shizuoka (thanks Jon, Ray, Tim and others), it is now time to
think about controlling the 5HP shunt wound DC spindle motor. This is a
180V armature 200V field motor. The spindle drive is nonworking, old,
outdated, huge, 3 phase powered, and I don't want to debug it. It is the
main reason I got the beautiful condition mill for so cheap (new spindle drive
was going to cost the previous owner $7500 from fujitsu).
So, now I am thinking about gangin two or three
gecko drives together...(just kidding)
Seriously, I am torn between building something
simple, like an RC controlled SCR, or buying a KBCC-255 which is a KB
electronics 5HP comercial version of the RC controlled SCR for $209. Or
buying a KBRG-255, which is a 4 quadrant regenerative 5HP drive with armature or
tach feedback for about $450.
None of those solutions is really going to help me
when it comes to spindle position for the tool changer. A true servo drive
in the 5HP range is quite a bit more though (maybe $600 to $800 from A-M-C), and
I have to think about supplying it with rectified 230VAC safely (The KBCC and
KBRG controls have this built in, with an active rectifier or
something).
Since EMC doesn't support tool changes anyway, I am
wondering if I should just get something to work for right now, and then upgrade
to servo control later when I have worked on the tool change logic and
hardware. One idea I had was to use a high power relay to switch the 5HP
armature windings over to a gecko drive (once the 5HP drive has come to a full
stop) and servo the 5HP motor slowly to the correct spindle position at 60V or
so (my x,y,z axis supply rating).
Suggestions?
Did I mention I don't want to repair the old
spindle drive?
Thanks again guys!
Richard
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