G Code issue? Torch just goes into the table -_-

[cherokee-mfg]

So at line...

Code: Select all

N150 G28.1 Z0.12 F19.685

My torch height controller plunges into my table. I just started trying to learn how to decipher G Code and the only thing I've half way successfully burned out is the Scorpion from the Sheetcam test files.

Thank you for your time.

Also, there's the SVG file attached. I had to scale down the original drawing to made it the right size in sheet cam. Came out to be 680 inches long ways at first... supposed to be 26.5. Scaled at 3.9% (26.5 divided by 1680 = 0.0389 ((3.9))).

Code: Select all

N0010 (Filename: 9inscaled.tap)
N0020 (Post processor: MP3000-DTHCII+scriber2.scpost)
N0030 (Date: 16/04/2016)
N0040 G20 (Units: Inches)
N0050 F1
N0060 G53 G90 G40
N0070 S10 (DTHC is off)
N0080 (Part: 9inscaled)
N0090 (Operation: No Offset, Color 0, T1: Plasma, 0.035 in kerf)
N0100 (tool number: 1  Feedrate: 4) 
N0110 (No Stored DTHC parameters in this POST) 
N0120 G00 Z1.5000
N0130 X4.6133 Y6.0197
N0140 Z0.1500
N0150 G28.1 Z0.12 F19.685
N0160 G92 Z0.0
N0170 G00 Z0.0591
N0180 G92 Z0.0
N0190 G00 Z0.1500
N0200 M03
N0210 G01 Z0.0600 F60.0
N0220 S20 (DTHC is on)
N0230 F4.0
N0240 G02 X8.6930 Y8.0556 I8.2872 J-11.5009
N0250 X13.1678 Y8.9044 I5.9267 J-19.0261
N0260 X15.4638 Y8.6183 I-1.3077 J-19.8501
N0270 X20.5803 Y6.7847 I-2.8632 J-16.0454
N0280 X26.5257 Y0.0000 I-6.6756 J-11.8471
N0290 G01 X0.0000
N0300 G02 X0.9942 Y1.9932 I15.0161 J-6.2453
N0310 X4.6133 Y6.0197 I11.4602 J-6.6610
N0320 M05
N0330 G00 Z1.5000
N0340 X0.0000 Y0.0000
N0350 S900 
N0360 M22 
N0370 S10 (DTHC is off)
N0380 M22 
N0390 M05 M30

[WyoGreen]

What are you using for sensing the surface of the metal?

I tried opening your .svg, but all I saw in sheetcam and CorelDraw was a half circle.

Steve

[cherokee-mfg]

I'm not sure what you mean by what I'm using for sensing the surface of the metal... When I cut out the scorpion, it sensed it. Now that I'm using my own drawing and gcode, it's not.

I uploaded the original file "9in"

[cherokee-mfg]

I just went to my table and used scale 1:1 in sheetcam with the 9in.svg file and it was the right dimensions >_>

I still can't figure out how to get my Z not to plunge into the table...

[acourtjester]

since you did not supply much info about your table and the electronics I am guessing you have some CandCNC due to the heading in your G-code.
you need to see if you have a delay in your tool setup. I sounds like you need a delay at the start so the DTHC does not start until after the arc has stabilized. see attached

delay.jpg (38.21 KiB) Viewed 2476 times

[thundergun9001]

Thank you for your input, I'm trying what you said now.

[thundergun9001]

I actually don't have all those settings....

[thundergun9001]

I tried adding a 1.5 second delay and a few more things. I tried editing my g code by hand. Line N150 where the torch messed up.. I deleted the Z code. However, it did not go far enough down.

I believe I have a problem with my DTHC.

Please help, we're so close. We cut out in a couple hours, today could really be the day.

What should I manually input to control my torch height when the torch initiates?

[acourtjester]

I would contact the people at CandCNC I don't know about the post processor you are using they will.

[thundergun9001]

Thank you for your assistance.

[BTA Plasma]

Look at your plunge rate. By the time you have met your cut height your THC delay is gone. Fix your plunge rate and try 60-80ipm to start. Then check your THC delay in Mach to see if your way off.

[WyoGreen]

I'm not sure what you mean by what I'm using for sensing the surface of the metal... When I cut out the scorpion, it sensed it. Now that I'm using my own drawing and gcode, it's not.

I uploaded the original file "9in"

When I asked about how you're sensing the top of the metal, there are 2 main ways of doing that. One way is lowing the torch to the metal, and keep going until a switch in the torch mount trips. The other is ohmic sensing, where the torch goes down until it touches the metal, then a circuit is completed thru the torch tip and tells Mach where "0" torch height is. Mach needs to know where the top of the metal is to set the initial pierce height, and the subsequent lowing to cut height.

Your line "N150 G28.1 Z0.12 F19.685" is the start of that process. When you said your torch was plunging into the table at the start, I thought perhaps your height sensing was somehow not working.

Steve

[thundergun9001]

So I've been back at my table this morning and I tried the scorpion again. I'm leaving my torch off due to some electrical issues but I'm doing dry runs. The scorpion does fine and the g code looks different. I keep getting errors about DTHC being off when I try to run the g code I produced in sheetcam from my svg files.

So close yet so far.

[ben de lappe]

I'm curious about your torch height control. Depending on what you have it runs at a set voltage to keep from diving into the material in curves etc. Possibly could be part of your issue though I'm not certain of your setup.

[sphurley]

The only way your are going to get some real help is listing what you have. Table make, Plasma machine, system/DTHC control, version of sheetcam, etc.
You post above shows no DTHC settings. Your tools look like you created them. If you really have a CandCNC system and lets say a Hypertherm, then they did all the tool setup for you.
Fill us all in and then we can give some real help

[cherokee-mfg]

Does anyone know why my G Code has "S10 DTHC is OFF"? Just got some parts changed out on the table and I'm arcing again, but having gcode issues with dthc

[motoguy]

Does anyone know why my G Code has "S10 DTHC is OFF"? Just got some parts changed out on the table and I'm arcing again, but having gcode issues with dthc

Usually that's caused by having a cut rule that disables the DTHC for certain features where the table speed slows (circles, corners, tight arcs, etc).

[cherokee-mfg]

Okay cool so I'm going to look for that... I used the scorpion today and cut two out, it worked fine.

I just went into my cut rules and deleted one that said dthc off and left the one that said dthc on but it still didnt work. I still have gcode that says dthc off.

[cherokee-mfg]

I just deleted every tool that said DTHC off, ran the post processor and I STILL have code that says DTHC off, no DTHC parameters stored in this post, etc.

[cherokee-mfg]

This is still my problem.

N0010 (Filename: 9inscaled.tap)
N0020 (Post processor: MP3000-DTHCII+scriber2.scpost)
N0030 (Date: 16/04/2016)
N0040 G20 (Units: Inches)
N0050 F1
N0060 G53 G90 G40
N0070 S10 (DTHC is off)
N0080 (Part: 9inscaled)
N0090 (Operation: No Offset, Color 0, T1: Plasma, 0.035 in kerf)
N0100 (tool number: 1 Feedrate: 4)
N0110 (No Stored DTHC parameters in this POST)

No stored DTHC parameters in this post, DTHC is off.....

[tcaudle]

DTHC On and off is not controlled by the Toolset or tool settings. The toolset can only define if its OFF GLOBALLY and the code is different : S999. It makes MACH ignore any S20 (DTHC on) even if its in the code. DTHC control is based on the toolpath and cut rules not the tool table value. The system is programmed to turn off the DTHC at the end of each cut because you don't want it on during a pierce or plunge move and you don't want it ON if the "min Cut Length for THC" is less than the setting. I still am not sure of your problem or what hardware you have . There is a general OFF at the beginning of the DTHC to make usre it starts out off and that certain things turn it on. The initial command to turn off the DTHC (line 70 above ) will ALWAYS be there. ON and OFF is dynamic. So are you trying to get it to turn off and cut without it or to come on and adjust? It if turns on and plunges then you have something set wrong or you are not getting back the right Torch Volts. If you touch off is wrong it won't cut right .