Messages

51

Mach4 General Discussion / Re: Mach4 Post Processor for Plasma in Fusion 360 and a ESS motion - Cant Find One

« on: May 16, 2023, 05:34:43 PM »

Hi,
so what plasma machine do you have?.

There are three things that ALL plasmas have that are intended for machine use.

The first is an input to start the arc, it replicates the trigger on a handheld torch. The best solution is s set of isolated relay contacts with the relay
under control of  Mach. Sounds like that's what you've got.

The second is ARC_OK. When a plasma arc first starts the tip is energised and the nozzle is earthed. The plasma current is usually limited to 20A
or so otherwise the nozzle will be wrecked. If the arc in in reach of the plate the arc will 'transfer' to the earthed plate, and the plasma machine will recognise this
and release the earth on the nozzle thereby preventing further excessive wear while the arc is now formed between the tip and the plate. Now the plasma current will ramp up
to whatever you have set the machine at. The 'transfer' and current ramp up signal that the machine is ready to cut and it will close a set of relay contacts (typically)
and that is the ARC_OK signal. Mach would use this to determine that the plasma has established an arc and that it has successfully transferred to the plate. It will now
assume the correct pierce height and the cutting will begin.

The ARC_OK signal is critical. If the m3() macro in Mach4Hobby Plasma screenset does not recieve an ARC_OK signal after a few seconds it will fault out.

I noted in a previous post that you start the plasma and wait for a fixed delay, two second or whatever. That might be how you'd do it manually but a machine plasma uses
the ARC_OK signal.

I worked for seven years for a company that sold and serviced welding equipment. I was an electronic repair tech, and used to repair plasmas and plasma tables.
Our premier brand was Hypertherm, but over the years I worked with  Kaliburn, ESAB, Lincoln, Miller, Thermal Dynamics and who knows how many Chinese machines.
All of the good ones had an ARC_OK signal.

The last feature that is required for machine use is a arc voltage output. Hypertherm have a 50:1 voltage divider, while some of the other brands copied that same 50:1,
others were 20:1, 25: 1, 30:1 etc. This voltage is used by the THC module to monitor the arc voltage.

One other feature you'll need is a probe input.  When you put a piece of plate in the machine the torch needs to descend and touch off the plate to know where the top surface is.
Without knowing that then your Pierce Height or Cut Height  don't really mean much do they? And what happens if you take a 3mm plate out and put in a 12mm plate for the next part?
If you don't have some routine to tell where the new surface level is the machine will drive to '3mm off the plate being pierce height' only to find that is still below the surface
of the piece of 12mm plate you just put in. The traditional way to do this is to use a g31 probing move. The torch descends from some safe height until the nozzle touches the
plate and Mach detects that touch or probe event and stops. It latches the Z axis location so it knows where the surface of the plate is. Many plasmas have a connection on the plasma
machine which is hooked to the nozzle of the torch to facilitate this touch off. Its sometimes also called Ohmic probing.

Craig

52

Mach4 General Discussion / Re: Save #VARS

« on: May 16, 2023, 04:53:36 PM »

Hi,
I've always found tattooing on the wife's forehead a convenient location to store important data. Limited re-write potential!

Craig

53

Mach4 General Discussion / Re: Mach4 Post Processor for Plasma in Fusion 360 and a ESS motion - Cant Find One

« on: May 16, 2023, 01:03:30 AM »

Hi,

If I had used the Mach4 Plasma screenset, what post processer in fusion 360 would I use for my “plasma cutting”tool paths?

The same one, it seems the Mach3Plasma post.

You seem to be fixated on the post....and the post has got ZERO to do with it. The post generates Gcode , but Gcode does not start or stop the torch,
that is m3 or m5.

The machine behaviour in response to m3 or m5 is where you need to concentrate. You have already proven that you can get perfectly good tool paths from Fusion and
the Mach3Plasma post.....but what you can't do is turn the torch on or off.....and that's got nothing to do with Fusion or the post.

The Mach4Plasma screenset already has a sophisticated m3 routine built in....there is no need for you to code it.

It first touches off the material surface. Note this procedure is optional, although you'll certainly want it if you are using different thickness plate. Anyway once the machine
touches off the plate and effectively determines where Z zero is then in raises to the torch start height....whatever you program in. Then it fires the torch and waits for the
ARC_OK signal. If it doesn't get an ARC_OK signal after about three seconds it faults, ie the torch has been told to fire but it fails for whatever reason.

Assuming the torch does fire and Mach receives the ARC_OK signal then the torch lowers to the pierce height, whatever you set. After a pierce delay of so many seconds, whatever you set,
then it starts to decsend to its target cut height, agin whatever you specify and starts the tool path.

What you really need, as a minimum, is a circuit to activate to turn the arc on and an ACR_OK signal. Ideally you'd have a probe input so the torch can touch off too.

Do you have those?

Craig

54

Mach4 General Discussion / Re: Mach4 Post Processor for Plasma in Fusion 360 and a ESS motion - Cant Find One

« on: May 15, 2023, 11:44:06 PM »

Hi,
I've just been experimenting with the Mach4 Plasma screenset and it appears like m3 is already coded and working. Is there a reason you don't use it?

Craig

55

Mach4 General Discussion / Re: Mach4 Post Processor for Plasma in Fusion 360 and a ESS motion - Cant Find One

« on: May 15, 2023, 11:33:18 PM »

Hi,
this one is really simple, or at least can be simplified down to a couple of lines.

A more sophisticated macro would be bigger and take more effort.

Lets say for the moment you ignore all Z axis movement, that is to say you jog the machine to the start point and set it to the correct cutting height.
Then all you have to do is say Turn the Arc On, wait for 2 seconds and return. That would be enough, two, three maybe four lines.

A slightly more complex start routine would be Turn the Arc ON, wait until the ArcOK signal is received and return. If the plasma refuses to fire then the ArcOk signal
will never happen, ie the arc did not start so there is no point moving to cutting stuff because there is no arc.

A more complex one again would be to go to some safe height before starting the arc, the Start the Arc, wait until ArcOk signal, drop to pierce height, wait 2 seconds to pierce,
drop to cut height and return.

So you can see that you can start very simple and add nuances to match your requirement, but the simplest is about three or four lines.

What signal have you used to control the Arc relay? Have you hooked up the ArcOK signal from the plasma and to what input did you hook it to?

Craig

56

Mach4 General Discussion / Re: Mach4 Post Processor for Plasma in Fusion 360 and a ESS motion - Cant Find One

« on: May 15, 2023, 10:29:10 PM »

Hi,

Mach3 for my plasma cutting and wait for somebody to develop a plasma cutting post processor for Mach4.

I think you'll be waiting a long time....what you want is not done by a post processor, what you require is to set up your machine with a compliant m3()
which is a function of your machine, and that is not a post process at all.

What you are actually saying really 'I want someone to write some magic code so I don't have to', and that tends to take a long time.

Craig

57

Mach4 General Discussion / Re: M6 Lua script help!

« on: May 15, 2023, 10:12:17 PM »

Hi,
This is typical Mach3 code:

Code: [Select]

If GetCurrentTool() = 2 then
   Code"G0 A45"
   While Ismoving()
   Wend
   End If
The Lua equivalent is something like this:

Code: [Select]

function m303()
local inst = mc.mcGetInstance()
local selectedTool = mc.mcToolGetSelected(inst)
selectedTool = math.tointeger(selectedTool)
local currentTool = mc.mcToolGetCurrent(inst)
currentTool = math.tointeger(currentTool)
if(currentTool==2)then
mc.mcCntlGcodeExecuteWait(inst,"G0 A45\n")
end
end
if(mc.mcInEditor()==1)then
m303()
end

A few things to note here, firstly I have encapsulated the code in a function called m303(). This allows you to run the code in the ZeroBrane editor and test and debug as you go.
The little:
if(mc.mcInEditor()==1)then
      m303()
end

at the end is what allows the code to run......a function must be called and if Mach is 'InEditor' then it will call m303(). Then the function will run until it ends and then returns to the same place it
was called from.

mc.mcCntlGcodeExecuteWait(inst,"G0 A45\n")  this is the line that actually does the business, but note that a function is called 'mc.mcCntlGcodeExecuteWait(........)' and it will execute and Mach will wait
until it completes, there is no need of the While IsMoving() palava.

Translating VBasic into Lua is not especially productive, there are enough differences that writing Lua anew is likely the best result. I mentioned this only because the function:
mc.mcCntlGcodeExecuteWait(........) is a classic example of how Lua/Mach4 coding differs from VBasic and you do not want to replicate VBasic, you want to use what has been provided for in
Lua and mach's API.

Craig

58

Mach4 General Discussion / Re: Mach4 Post Processor for Plasma in Fusion 360 and a ESS motion - Cant Find One

« on: May 15, 2023, 09:08:50 PM »

Hi,
I don't use either Laser or Plasma so I'm having to guess to a certain extent.

m62/m63 are for lasers. It turns the laser on, but ONLY when the machine has started to move, otherwise the laser would burn a spot right at the start. m63/m63 are not right for you.

First thing you may note is that I use lowercase m or lowercase g in all Gcode....because Mach's Gcode interpreter parses all Gcode to lowercase, strips out leading zeros and whitespace. Thus
M03 becomes m3, etc. When the interpreter encounters an M3 for instance its going to search for code starting m3. To make sure it finds it then use its preferred format, ie lowercase and without
leading zeros. Note that I often still use whitespace to separate items for readabilities sake, but should in truth remove whitespace as well so g1x16.67y45.67f556 not g1 x16.67 y 45.67 f556.

When Mach encounters an m3 it will search in the macros folder of the current profile, if it does not find it it will search 'up the file tree' until it does. Normally this means that Mach will
use the built in m3 that turns the spindle one. Presumably the built-in m3 will turn on the SpinOn signal and generate the required PWM to meet the prevailing S word etc. In your case you want
m3 to turn on the torch so you will have to write your own m3() function and put it in the macros folder of your profile. Thus Mach will find and execute your macro BEFORE it searches to find the built-in one.

I would guess you need to code something like:
Function m3()
1) g31 probe the surface of the material
2) Back off the surface of the material by 20mm or so
3) Activate the torch turn on relay.
4) Wait until the ARC_OK signal is received from the plasma. If an ARC_OK signal is not received within 5 seconds....bail ARC_FAIL_YOU_BLOODY_PLONKER.
5) descend to pierce height
6) Wait for the pierce delay
7) Return....this signals that the torch has fired, arc stabilised, pierced and is now ready to cut.

And your m5 would be something like:

Function m5()
1) De-activate the torch relay
2) Lift off the material by 20mm
3) Return

Craig

PS: the ARC_FAIL_YOU_BLOODY_PLONKER is optional!

59

Mach4 General Discussion / Re: Mach4 Post Processor for Plasma in Fusion 360 and a ESS motion - Cant Find One

« on: May 15, 2023, 08:15:28 PM »

Hi,

I have just generated another toolpath for a somewhat smaller part. I ran the Mach3Plasma post and have run the code on my mill. It runs fine, but obviously the spindle turns on
rather than a plasma, but the code runs fine with the correct clearance for the width of the cut.

As to what constitutes an decent m3....well.

Craig

60

Mach4 General Discussion / Re: Mach4 Post Processor for Plasma in Fusion 360 and a ESS motion - Cant Find One

« on: May 15, 2023, 07:57:19 PM »

Hi,
this is the Gcode generated by Fusion using the Mach3 Plasma post:

Code: [Select]

N10 G90
N15 G71

(2D Profile1)
N20 G0 X22.67 Y-2.5
N25 M3
N30 G4 P1.
N35 G1 X27. Y0. F1000.
N40 G3 X-27. I-27. J0.
N45 G3 X27. I27. J0.
N50 G1 X22.67 Y2.5
N55 M5


(2D Profile2)
N60 G0 X184.83 Y-117.5
N65 M3
N70 G4 P1.
N75 G1 X180.5 Y-120.
N80 G2 X180. Y-120.5 I-0.5 J0.
N85 G1 X-180.
N90 G2 X-180.5 Y-120. I0. J0.5
N95 G1 Y120.
N100 G2 X-180. Y120.5 I0.5 J0.
N105 G1 X180.
N110 G2 X180.5 Y120. I0. J-0.5
N115 G1 Y-120.
N120 G1 X184.83 Y-122.5
N125 M5

N130 M30
And there is nothing about it which is alien to Mach4. The only thing is that it uses M3 followed by a G4 P1 to turn the torch on. Have you a properly configured M3
in your profile?

Craig