As with the main GUI, the plasma screen is designed to be used with a touch screen and is thus optimized for touch
It can however be used with keyboard and mouse
[gmoccapy wiki page]
The plasma screen has been included in the latest master branch. It can be found under the sim directory. You will be required to copy all the relevant files to your config. More on this later.
Plasma operations on CNC machines is a bit of an orphan process.
When cutting metal with a flame, the uneven heating up of the metarial will cause the sheet to bend and buckle. To start with, most sheets of metal does not come out of the mill or press in a very even or flat state. Thick sheets (30mm plus) can be out of plane as much as 50mm to 100mm.
Most CNC gcode programs will start from a know reference or a piece of stock that has a know size and shape. Gcode is written to rough the excess of and finally cut the finished part.
With plasma the unknown state of the sheet makes it impossible to generate gcode that will cater for these variances in the material.For this reason the THC ( Torch Height Control ) concept was designed. More detail on THC later in the document.
The purpose of the THC function is to make sure that the torch remains at a certain height above the work piece. Not having gcode to do this, one has to interject somewhere in the control loop to get the Z axis to track the material height. By nature of this statement it is clear that plasma and THC does not adhere to the rules for normal CNC and has to be treated with caution.
Suffice to say that it is almost impossible to do decent production plasma cutting without a proper THC system implemented.
All of these things happen outside of the normal gcode arena. That means we will have some component that does all this work as well as create an interface to some hardware that will in turn interface with the plasma equipment. Well that is not all entirely true as it depends on how you implement your THC functionality. In the next section we will deal with the various methods of control.
o<touchoff> sub (#1 pierce height, #2 pierce delay, #3 cut height, #4 switch offset) F500 G38.2 Z-300 (Probe to find the surface) G92 Z-30 G38.4 Z5 G91 G1 Z#4 (Raise up to Offset) G90 G92 Z0 (Set Z0) G1 Z#1 M3 S1 M66 P0 L3 Q5 (Wait for Arc OK from Torch) G4 P#2 (Pause for pierce delay) F500 Z#3 (goto cut height) o<touchoff> endsub M2
o<touchoff> sub (#1 pierce height, #2 pierce delay, #3 cut height) #<arc-fails> = 0 F40 o100 do G38.2 Z-1.25 (Probe to find the surface) G91 G1 Z0.185 (Raise up to Z0) G90 G92 Z0 (Set Z0) G1 Z#1 (Raise to pierce height) M3 S1 (Fire torch) M66 P0 L1 Q2 (Wait 2 seconds for Arc OK from Torch) o200 if [#5399 EQ -1] (Check to see if torch failed to fire) (MSG, Arc Fail) M5 #<arc-fails> = [#<arc-fails> + 1] o300 if [#<arc-fails> GT 3.0000] (Check if torch has failed 4 times in a row) Z2.0000 (raise torch high enough to change consumables) #<arc-fails> = 0 (reset arc failure counter) M1 (pause) o300 endif o200 endif o100 while [[#5399 EQ -1]] G4 P#2 (Pause for pierce delay) F25 Z#3 (goto cut height) o<touchoff> endsub M2This two pieces of code will probe the surface of the material and adjust the Z axis to the correct pierce height. It will start the torch and check for ARC_OK signal. If the ARC_OK fails, as in the case of the second piece of code, it will retry several times after which it will abort the operation. These are examples and might contain errors. Please check them before using.