On 2010-07-09, Ignoramus6355 wrote:
I started wiring everything in as professional manner as I am able to
do. I use DIN rail to mount as much stuff as possible, use DIN
terminals wherever possible, and I route wires through wire channels.
I connected my AMC 30A8T drive to the power supply and tachometer, so
that it would operate in tach mode. I made sure that all DIP switches
are set properly for tach mode.
Pictures of wiring are here.
http://igor.chudov.com/projects/Brid...iring-7670.jpg
Looks nice.
The good news is that after some false tries, tach mode works
great. The X axis moves at about 70 IPM max, or super slow, as
commanded. I use a separate little power supply for commands. The
drive develops 68VDC and appx. 3 amps to move the table at highest
speed.
Without cutting load, of course.
The more disconcerting news is that if a tach cable is not connected,
the drive goes into a runaway mode EVEN IF NO INPUT SIGNAL is
present (inputs shorted to each other).
Usually, there is a zero trimpot on the servo amp (drive) which
will first off eliminate drive with zero input signal voltage. When
this is done, it might also eliminate the runaway problem with no tach
feedback connected -- but I'm not sure of that.
I presume the black module near the bottom marked 'X' is the
servo amp?
This means that if I do a shoddy job wiring those tach contacts, or
the open barrel terminals fall out, or anything else, I will be in a
world of hurt.
So -- this is a motivation to do it right. :-)
I know that EMC has some protection against following error, but I am
not sure how robust is that.
Besides a lot of simple jobs facing me, I have a big job, which is
installing new encoders and making mount plates for same.
After this, I will try to create a "One-Axis CNC" machine without
worrying about other axes.
Anyway, I have one little thing to celebrate (the tach mode).
Indeed -- congratulations.
I also have a good grip on using that open barrel terminal crimper and
all crimps now come out looking good. I do a pull test on each, of
course.
Especially with the new motivation. :-)
Enjoy,
DoN.
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