On Thu, 24 Nov 2005 04:30:53 +0000, don't use this address to reach me
wrote:


Thanks Wayne - good input - I am currently under the impression that
there are 3 motors (spindle, traverse, and coolant), and I probably
won't use coolant. On my lathe, I used a VFD and just removed ALL the
pre-existing wiring and contactors, etc and let the VFD to the
start/stop/reverse work - that worked out nicely. I don't really
trust rotary converters because of the need to balance them
electrically, and furthermore they take up space (which is something I
don't have), so a solid state approach is much more attractive. I've
thought of driving a 3 phase transformer with a primitive VFD (well, a
solid state single to three phase converter), but I don't know what
the reflected transformer loads would be back on the device. So, if I
can convert to 220V, that will be quite helpful. It still leaves the
trick of deciding whether to rewire and exploit the new solid state
controls or not.

Hmm. Well first off you'll need to check the coolant pump. It may or
may not be 3 phase. I can't imagine not using coolant of some form on
a milling machine. I've never used it on a lathe but it's pretty much
essential in milling from my experience.

The way I see it you may end up needing two VFD's to make this thing
run properly. At least you will if you want to even think about using
the rapid traverse feature (and I'm not to sure about how well that'll
work off a VFD since it uses the sudden reversing of the motor to
shift into rapids). I suppose you could leave the feed motor on at all
times (there's really no reason to turn it off, mine has not been
turned off on purpose ever). However that will add up to a pretty good
sized load for a VFD. I don't remember what HP the feed motor is but
the main spindle motor is big enough that you'll want a 5HP VFD and
higher HP VFD's which will take single phase input are harder to find.

Another point is the fact that the main motor is a special built
motor and would not be easy to replace. On the other hand the feed
motor is pretty much a normal motor and could be replaced if needed.

by the way, Rolf at Abene says that the machine was made in 1970. I'm
a bit farther away from it than you, since I'm on the left coast - I
expect it to show up any week now, as I frantically move stuff around
to try and ensure I have a place to put it.

Interesting. I wonder when mine was made. There's enough differences
between the two in minor details which makes me believe that mine
might be slightly newer than yours.

Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm