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Pete C. Pete C. is offline
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Default Testing servos/Drives UPDATE


Ignoramus3037 wrote:

On 2010-06-15, Karl Townsend wrote:

"Ignoramus3037" wrote in message
...
Since I fully gutted the cabinet and removed all inside wiring (but
not wires coming from the outside to the huge terminal block), I was
able to test more stuff.

I did test the X-Y servo motors last night by just applying voltage to
their DC leads. They moved nicely. At 30 volts incoming, the X-Y table
moved at about 1 inch per second, and the motors consumed appx. 1.3
amps.

What this tells me is that the mill is not "broken" (no surprise
here), and also that 80 volts and 20 amps total capacity of my power
supply, should be plenty for my light home use hobby purposes.

What I will do, for now, is just make a convenient terminal block on
the outside of the mill, so that I could move X,Y,Z by applying DC
voltage to these terminals.

I will hopefully get to that tonight. Also tonight, I will start
making aluminum adapter plates for the US digital encoders.

The next step would be to connect encoders to Jon's motion controller,
apply voltage to DC motors and see encoder data displayed on the PC.

I will try to spend a long time without hooking up servo drives, to
wire and program as much as possible of safety related stuff (limits,
estop etc). My own hands will be motor controllers, so to speak.

With the encoders working, and hand motor control, this will be
actually a fully working semi-manual mill!

i


Iggy, you're likely to end up like me. I enjoy making old iron better than
new so much that this has become my metalworking hobby. Looks like you're
headed toward a wonderful machine for less than $1K out of pocket.


I think so too.

Now, do you think that I am on the right track with my plan to
implement everything except servo drives first, and wait with servo
drives until everything else has been debugged? Does that make sense?

i


Not really, being able to move the machine axes under CNC control is
pretty integral to testing and debugging everything else. Since it's
already a CNC machine, you already have limit switches in the
appropriate places already, so the only debugging involved will be
configuring the control software to know where to find those inputs.
Control of outputs such as coolant and spindle control is similarly
easy.

There really isn't that much "everything else", the servos are the bulk
of a basic CNC mill beyond the control. The rest is six limit switches,
a coolant pump relay, and spindle control which could be a serial
connection to the VFD or fwd / rev signals and a speed voltage.

I don't recall your mill having an ATC, but if it does, ignore it until
you get the rest working properly.