Re: need help, brushless drive

Rick said:

>I have been collecting parts for a small gantry cnc
>mill, and I just
>recieved two Motion Science Inc. (cleveland motion
>controls)
>brushless amplifiers, model MBLX16024HP-01.

Rick:
Thought about bidding on those drives. As a result of
long, sad experience, I don't buy drives without a
manual. Too many nice looking yet essentially
worthless drives sitting in the basement right now as
it is. I really wish I could find a manual for an
Electrocraft BSA30. At least you have that data
sheet.

I expect to see a lot more CMC stuff on the surplus
market with their approach to literature -- after they
go bankrupt. It's a buyers market.

The downside to those drives is that they are appear
to take an analog control signal. So you have to get
that from somewhere, either D/A converters or the
Rutex Step/Direction to analog converter.

If it was me, I would seriously consider trying to get
the drives to work through experimentation. It's
somewhat unlikely you would smoke anything before it
faulted. You may have a problem in the halls
configuration. There are 2 configurations of halls
(60 and 120 degrees, I think). The drive will fault
if it doesn't like your motor's configuration. The
trick is to figure out which combination of halls goes
with which motor winding.
You may want to look at
http://www.a-m-c.com/support_docs.htm for the
installation and engineering manuals and the phasing
worksheet, they have a discussion of motor phasing.
Somewhere they have a list of which motors have what
configuration, probably in one of those two docs,
don't remember exactly.

The other issue is that it appears that you need to
supply an unknown voltage for the opto reference and
the shutdown input. I would guess ground for
reference and shutdown at 5,12, or 24 volts in that
order.

Finally, since nobody ever made a brushless motor with
a tach and stayed in business long enough for their
motors to be common on Ebay, you probably want to drop
the tach gain to zero. Hopefully the drive will
stabilize and not have too much torque ripple even
without a tach. As an aside, some AMC drives use an
encoder to simulate a tach.

Regards,
Eric







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