I am trying to figure out why my post is sprinkling THC on/off codes in my output.

Here’s the code

N0070 M10 (THC off)

N0080 (Part: 65mm Square Circledxf)

N0090 (Operation: Inside Offset, Circle, T1: 2mm Steel, 25A, Std Tip)

N0100 G00 X32.5000 Y22.8750

N0110 G28.1 Z3.00 F250.0

N0120 G92 Z0.0

N0130 G00 Z4.6500

N0140 G92 Z0.0

N0150 G00 Z4.0000

N0160 M03

N0170 G04 P0.1

N0180 G01 Z1.0000 F800.0

N0190 M10 (THC Off)

N0200 M11 (THC on)

N0210 Y7.8750 F960.0

N0220 G03 I0.0000 J24.6250

N0230 M11 (THC On)

N0240 (Operation: Outside Offset, 0, T1: 2mm Steel, 25A, Std Tip)

N0250 M05

I have a post rule that says for small circles, slowdown, turn THC off and then on after.

It seems that its turning it off for probing g28.1 but then on for the circle??

Do you get any THC on/off commands if you disable the path rules? ould you post your job file so I can see exactly what the rules are doing.

Job file attached and yes i get the codes if i disable the rule.

The rule say circles < 70mm dia reduce to 60% and THC off, at the end its THC on.

The square has loops on the corners.

Dave

I think I found the problem. It will be fixed in the next release (hopefully due out Monday).

Brilliant, thanks again Les.

Yes, it has just been uploaded.

Any idea where?

The downloads page lists the same as before and “check for updates” yields nothing.

That’s odd. Try refreshing your browser. You want V5.1.35.

Still not quite right - line 190 shows THC off for the circle, but immediately after, line 200 switches it back on??

Also line 70 switches it off ?

Line 230 is correct IMHO.

N0010 (Filename: 65mm Square Circledxf.tap)

N0020 (Post processor: Mach3 THC with scriber-edited.scpost)

N0030 (Date: 16/04/2014)

N0040 G21 (Units: Metric)

N0050 F1

N0060 G53 G90 G40 G64

N0070 M10 (THC off)

N0080 (Part: 65mm Square Circledxf)

N0090 (Operation: Inside Offset, Circle, T1: 2mm Steel, 25A, Std Tip)

N0100 G00 X32.5000 Y22.8750

N0110 G28.1 Z3.00 F250.0

N0120 G92 Z0.0

N0130 G00 Z3.9000

N0140 G92 Z0.0

N0150 G00 Z4.0000

N0160 M03

N0170 G04 P0.1

N0180 G01 Z1.0000 F800.0

N0190 M10 (THC Off)

N0200 M11 (THC on)

N0210 Y7.8750 F1120.0

N0220 G03 I0.0000 J24.6250

N0230 M11 (THC On)

N0240 (Operation: Outside Offset, 0, T1: 2mm Steel, 25A, Std Tip)

N0250 M05

N0260 G00 Z10.0000

N0270 X68.5750 Y68.2000

N0280 G28.1 Z3.00 F250.0

N0290 G92 Z0.0

N0300 G00 Z3.9000

N0310 G92 Z0.0

N0320 G00 Z4.0000

N0330 M03

N0340 G04 P0.1

N0350 G01 Z1.0000 F800.0

N0360 G03 X65.3750 Y65.0000 I0.0000 J-3.2000 F1600.0

N0370 G01 Y-1.6331

N0380 G03 X66.6331 Y-0.3750 I1.2581 J0.0000

N0390 G01 X-1.6331

N0400 G03 X-0.3750 Y-1.6331 I0.0000 J-1.2581

N0410 G01 Y66.6331

N0420 G03 X-1.6331 Y65.3750 I-1.2581 J0.0000

N0430 G01 X65.0000

N0440 M05

N0450 G00 Z10.0000

N0460 X0.0000 Y0.0000

N0470 M05 M30

In fact line 190 and 200 are not needed at all as it is already turned off in line 70.

These two lines appear to be not needed and will infact turn the THC on when it should be off!

Is that with the job file you posted here? This is the code I get:

```
N0010 (Filename: 65mm Square Circledxf.tap)
N0020 (Post processor: Mach3 THC with scriber.scpost)
N0030 (Date: 17/04/2014)
N0040 G20 (Units: Inches)
N0050 F1
N0060 G53 G90 G40
N0070 (Part: 65mm Square Circledxf)
N0080 (Operation: Inside Offset, Circle, T1: Plasma, 0.75 mm kerf)
N0090 G00 X1.2795 Y0.9006
N0100 G28.1 Z0.12 F19.685
N0110 G92 Z0.0
N0120 G00 Z0.0591
N0130 G92 Z0.0
N0140 G00 Z0.1575
N0150 M03
N0160 G04 P0.1
N0170 G01 Z0.0394 F31.4961
N0180 M10 (THC Off) On small circles
N0190 Y0.3100 F37.7953
N0200 G03 I0.0000 J0.9695
N0210 M11 (THC On) On small circles
N0220 (Operation: Outside Offset, 0, T1: Plasma, 0.75 mm kerf)
N0230 M05
N0240 G00 Z0.3937
N0250 X2.6998 Y2.6850
N0260 Z0.1575
N0270 M03
N0280 G04 P0.1
N0290 G01 Z0.0394 F31.4961
N0300 G03 X2.5738 Y2.5591 I0.0000 J-0.1260 F25.1969
N0310 G01 Y-0.0643 F62.9921
N0320 G03 X2.6234 Y-0.0148 I0.0495 J0.0000 F25.1969
N0330 G01 X-0.0643 F62.9921
N0340 G03 X-0.0148 Y-0.0643 I0.0000 J-0.0495 F25.1969
N0350 G01 Y2.6234 F62.9921
N0360 G03 X-0.0643 Y2.5738 I-0.0495 J0.0000 F25.1969
N0370 G01 X2.5591 F62.9921
N0380 M05
N0390 G00 Z0.3937
N0400 X0.0000 Y0.0000
N0410 M05 M30
```

By the way, in the path rules editor turn on ‘show rule names in g-code’. It helps you work out which rules are triggering.

Yes that’s the one. Odd that I’m seeing different results, I will try reinstalling and see what happens.

And I’ll try turning on the name dialogue, that could be very useful.

Dave

I used a new copy of the POST and now I get this result…

N0010 (Filename: 65mm Square Circledxf.tap)

N0020 (Post processor: Mach3 THC with scriber 2.scpost)

N0030 (Date: 22/04/2014)

N0040 G21 (Units: Metric)

N0050 F1

N0060 G53 G90 G40

N0070 M11 (THC off)

N0080 (Part: 65mm Square Circledxf)

N0090 (Operation: Inside Offset, Circle, T3: 6.35mm Steel, 30A, Std Tip, 112v)

N0100 G00 X32.5000 Y23.0000

N0110 G28.1 Z3.00 F800.0

N0120 G92 Z0.0

N0130 G00 Z3.9000

N0140 G92 Z0.0

N0150 G00 Z3.5000

N0160 M03

N0170 G04 P0.3

N0180 G01 Z1.0000

N0190 M10 (THC Off) (On small circles)

N0200 M10 (THC on)

N0210 Y8.0000 F490.0

N0220 G03 I0.0000 J24.5000

N0230 X33.9991 Y8.0459 I0.0000 J24.5000

N0240 M11 (THC On) (On small circles)

N0250 (Operation: Outside Offset, 0, T1: 2mm Steel, 30A, Std Tip, 106v)

N0260 M05

N0270 G00 Z10.0000

N0280 G00 X33.9991 Y8.0459

N0290 X68.5750 Y68.2000

N0300 G28.1 Z3.00 F800.0

N0310 G92 Z0.0

N0320 G00 Z3.9000

N0330 G92 Z0.0

N0340 G00 Z3.5000

N0350 M03

N0360 G04 P0.1

N0370 G01 Z1.0000

N0380 G03 X65.3750 Y65.0000 I0.0000 J-3.2000 F1600.0

N0390 G01 Y-1.6331

N0400 G03 X66.6331 Y-0.3750 I1.2581 J0.0000

N0410 G01 X-1.6331

N0420 G03 X-0.3750 Y-1.6331 I0.0000 J-1.2581

N0430 G01 Y66.6331

N0440 G03 X-1.6331 Y65.3750 I-1.2581 J0.0000

N0450 G01 X65.0000

N0460 M05

N0470 G00 Z10.0000

N0480 X0.0000 Y0.0000

N0490 M05 M30

Still not working

line 190 is kicking it off as per the rules but then line 200 is kicking it straight back on but not from the rule???

Could there be two versions of this post??

I’m not fully up to sped on heavily modding a POST file but there seems to be a section that turns THC on and off, this is interfering with the rules I want to use.

The rule is turning it off as needed but the POST is putting back on when it should be off.

Maybe the rules need a custom POST file??

Edit your post and make sure you don’t have any thcOnCode or thcOffCode defined. If you have anything defined for these codes they will conflict with the rules.

D’oh !

Now why didn’t I think of that?

Thanks again Les.

That fixed one issue, so as I’m still learning here, as an experiment, i tried the job below, picture attached.

N0010 (Filename: Test 1.tap)

N0020 (Post processor: Mach3 THC with scriber 2.scpost)

N0030 (Date: 25/04/2014)

N0040 G21 (Units: Metric)

N0050 F1

N0060 G53 G90 G40 G64

N0070 (Part: Test 1)

N0080 (Operation: Outside Offset, 0, T2: 1.5mm Steel, 30A, Std Tip, 103v)

N0090 G00 X41.3478 Y30.1053

N0100 G28.1 Z3.00 F800.0

N0110 G92 Z0.0

N0120 G00 Z3.9000

N0130 G92 Z0.0

N0140 G00 Z3.5000

N0150 M03

N0160 G01 Z1.0000

N0170 M101 (THC Off) (On arcs)

N0180 G03 X50.9478 Y20.5053 I9.6000 J0.0000 F2310.0

N0190 M102 (THC On) (On arcs)

N0200 G01 X72.6444 F3300.0

N0210 M101 (THC Off) (On arcs)

N0220 G02 Y9.4947 I14.3556 J-5.5053 F2310.0

N0230 M102 (THC On) (On arcs)

N0240 G01 X29.3556 F3300.0

N0250 M101 (THC Off) (On arcs)

N0260 G02 X0.5522 Y9.7414 I-14.3556 J5.5053 F2310.0

N0270 M102 (THC On) (On arcs)

N0280 M101 (THC Off) (On arcs)

N0290 X9.7414 Y29.4478 I14.4478 J5.2586

N0300 M102 (THC On) (On arcs)

N0310 M101 (THC Off) (On arcs)

N0320 X29.3556 Y20.5053 I5.2586 J-14.4478

N0330 M102 (THC On) (On arcs)

N0340 G01 X50.9478 F3300.0

N0350 X52.4478

N0360 M05

N0370 G00 Z10.0000

N0380 X0.0000 Y0.0000

N0390 M05 M30

It’s a dog-bone shape, so I presumed that THC would be off for the curves and on for the straights, this sort of made sense. However, as expected there is a pause at the end of the lead-in (unexpected but i can understand why) then one at each start/end of arc. The odd bit is the two extra pauses on the left hand arc, these made no sense and it seem sheetcam has thrown a wobbly at this point.

So, due to my lack of knowledge, is this shape possible with THC on/off or should it just be kept off and fingers crossed???

Using M-code macros will cause Mach to pause. I’m not sure what is happening oround line N0270. Could you post the job file so I can run it here and try to figure out what is happening.