Topics

1

Mach4 General Discussion / How to use an input to activate an output.

« on: August 02, 2020, 08:19:48 PM »

I would like to take an input to my motion controller (PMDX416) and in mach4 software use this input to activate an output.  To be specific I want to get step and direction inputs from an out side source (THC) and have a script (or some other method) that allows the inputs to activate the same outputs that now control a stepper motor.  This is for a plasma torch.  I have a torch touch off set up in the gcode.  When the code comes to the touch off I want mach4 to take control and activate the outputs as usual but when the probe action is over I want the input from the THC to control the output.  By design the THC should take the z axis output from the motion controller and pass it on through to the stepper controller when the torch is not on but it has stopped doing this.  I think maybe some failed circuit in the THC  is causing this.  The THC does still send step and dir signals when the torch is on.  This failure to send the output for the step and dir from mach4 to the THC causes the probe action not to work.  I have checked the motion controller and the outputs work but get lost trying to pass through the THC like they used to do.


If I were writing this in some simple programming language I might do;
if step signal from mach4 or step signal from THC (input) set output to true
  else set output false;
endif

With the same sort of routine for direction.
Unfortunately I do not know the LUA scripting to do this.  Can someone help.

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Mach4 General Discussion / mach4 cnc plasma torch touch off how to

« on: July 14, 2020, 09:10:33 PM »

OK I am using sheetcam to generate my Gcode.  Right now my pre processor is just about 6 lines.  What I want to know is how do I get the torch to touch off and set the height each time before turning on the torch.  I would like it to do this every time it turns off the torch and  starts to make a cut in another spot.  I have a THC that is standalone and once the torch is lighted it takes control of the Z-axis height and ignores input from mach4.  When the torch is off then mach4 can again take control of the Z-axis.  The THC is a Proma and has been a bit problematic for me to get it to give a steady control signal so after a while it builds up a lot of errors in distance and that is why I want to do a touch off to get a fresh start at the right height between each cut.  Does someone have a pre processor that would work with my setup that I could get a copy of? 

3

Mach4 General Discussion / Gcode

« on: October 21, 2019, 09:59:12 PM »

I was wondering if their is a gcode command to move an axis a certain amount Without specifying the exact xyz location.  For instance suppose the Z axis has been moved from the 0.0 location by a THC and the cnc does not actually know the axis has been moved and I want to lift the z axis 50 thousandths or lower it 50 thousandths.  I think I just answered my question.  If the cnc does not know the z axis has been moved and I tell it to move to 0.050 and then back to 0.0 it should move as if it were there from the start?  Does that sound reasonable? 

4

Mach4 General Discussion / I want to move 1 inch but move 5 total beginner

« on: July 28, 2019, 08:24:21 PM »

I am a total beginner to cnc.  I figured it would be easiest to build a cnc plasma table.  I have mach4 and the PMDX 416.  All of my movements are about 5 times larger than I want.  I tried jog and set incremental to 1.000 inch and it moves 5 inches.  How do I correct this problem?  My stepper motors have a pulley that runs a belt connected to the gantry for moving the X and a stepper motor with a pulley connected to move the Y axis.  The pulleys are about 2.5 inch in diameter.
I cannot find any place to change the distance the thing moves.   

5

Mach4 General Discussion / Newbie here and need some starting help

« on: December 05, 2018, 09:32:13 PM »

OK so I survived the download and the registration of the product key.  Now I need some extra information.  I want to make a cnc plasma cutting table and I do not know which tool to use to set it up.  Several icons were installed on my desktop one mach4 lathe, two mach 4 mill, a mach 4 router and mach4 tangential.  I have been reading the pdfs on mach4 and so far it has not told me which one is best for a plasma cutter.  I am suspecting the tangential is the right choice but I would like for an old hand to tell me what is best.  I know i have a long way to go so please help me get started.