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Author Topic: Piggybacking on / Hijacking An Existing CNC Controller  (Read 1189 times)

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Piggybacking on / Hijacking An Existing CNC Controller
« on: December 14, 2013, 11:45:50 AM »
I have a router made by Vision, with a Series II controller.  The controller as it sits now only accepts HPGL from a proprietary software supplied by Vision.  (I have it, but I don't like it - I want to do 3D work, so I'm attempting to retrofit it to work with Mach3.)

I've opened up the controller and isolated all the inputs / outputs that I need, except for the limit switches.  The steppers are driven by IM483 boards, which are quite well documented and I'm not finding many particular issues there.  I'll take STEP / DIR from each of the 4 to pins on a new DB25 connector that I'm adding to the housing, while leaving +5V connected to the existing controller.  I'm not bothering with a BOB here, as the drivers are fully opto-isolated, and they're still being powered by the PSU inside the controller.

Now the question I have about the drivers is the ENABLE pin.  It's currently being driven by the controller.  Should I leave it there, or connect it to the DB25 and drive it through Mach?  I'm guessing that this will kill the steppers when the E-stop is active?

Next question: the E-stop itself.  The controller has a 2-wire e-stop.  I'd like to keep it connected to the controller, as that will still be powering my spindle(s), dust collector, steppers, etc.    Can I simply take a tap off one leg of the e-stop wire (probably the black one) and run that to one of the input pins, and set that one as active-high in Mach3?  I guess the same question applies for the limit switches ...
Re: Piggybacking on / Hijacking An Existing CNC Controller
« Reply #1 on: December 18, 2013, 09:50:45 PM »
Well, problem solved, and mission partially accomplished.

1)  The existing controller doesn't enable +5V control power to the drivers unless it actually wants to run the motors.  This problem was solved by cutting the cable off a USB mouse and connecting that to P1:4 on the drivers for all 4 axes.

2)  Enable / disable is not needed.

3)  +5V from the USB will also run the E-stop.

So, now I've got the motors running.  It seems that all I need to do now is sort out the lead screw settings and motor tuning.  Oh, and maybe not have a rat's nest of unshielded wiring hanging loose and free.