[idahoflyfisher]

I have a DragonCut AIO from CandCNC. *Just* got it up and running. LPG/Oxy torch on it for now, home built table, 60x120 cut space. Cut some slat supports for the table, super simple: begin cut, slit, move along X-Axis 3", slit, repeat. Cut just fine.

Now the problem....

Trying to cut some *simple* 3.5" squares with a 3/8" radius on all 4 corners. Should be easy, right? problem is, the torch head keeps diving randomly into workpiece. Seems to usually be at the end of the radius, just starting on straight-away, however no rhyme or reason...

Getting very frustrated with it, don't know if it's my machine, my g-code, etc. I don't really think that it's my code, but don't know where to begin troubleshooting. Any help would be greatly appreciated.

[saghirecho]

Dear,
I think that problem in your circuit, if you build it own, please send its drawng, I will try to solve your problem.

[email protected]

[restless1]

Just a wild guess sounds like your Z is retracting in the wrong direction(or doing a touch off in the wrong z direction) ..
do you have the z axis set up properly to home or touch off correctly in the settings of your g code program be it mach3 or what not


Also is the anti dive switch on?
(just read that as a problem somewhere ...do not quote me

[idahoflyfisher]

Thanks guys, but I guess I should have been more specific. LPG/Oxy torch is a flame, not arc. So no plasma, no THC.

Running Mach3, tried it with the plasma profile, as well as the router profile. Same random diving.

[Tensaiteki]

Can you post a segment of the g-code where the dive happens? It might be a problem with whatever you are using to generate the code.

[idahoflyfisher]

N0340 G01 Y7.2800 Z0.6250 F20.0
N0350 G02 X0.9050 Y7.6850 Z0.62500 I0.4050 J-0.0000 F20.0
N0360 G01 X3.6550 Z0.6250 F20.0
N0370 G02 X4.0600 Y7.2800 Z0.62500 I0.0000 J-0.4050 F20.0
N0380 G01 Y4.5300 Z0.6250 F20.0
N0390 G03 X4.4650 Y4.1250 Z0.62500 I0.4050 J0.0000 F20.0
N0400 G01 X7.2150 Z0.6250 F20.0
N0410 G03 X7.6200 Y4.5300 Z0.62500 I-0.0000 J0.4050 F20.0
N0420 G01 Y7.2800 Z0.6250 F20.0

Not much to it, really quite simple. Seems to happen randomly at the end of some of the arcs. Like I said in original post, no rhyme or reason that I can see to why it's happening, completely random. I ran it through a dry (torch not lit) run, never dove once. Then it seemed like it would dive maybe every three, sometimes every single time.

[WSS]

Can you delete all but the first F20 (feed speed) and try that? I just looked at some of my oxy code and I only add more than one F if I am changing speeds for varying thickness. It may be what is troubling your torch. Aren't those problems annoying?

WSS

[jcc3inc]

Sir,

In looking at your first line, G1 Y7.628 Z.625 F20:

This is linear interpolation: in moving Y 7.628 you are asking for Z to move +.625 ???
I don't understand why there is any Z motion command with oxyfuel cutting? Usually the operator manually controls the height by looking at the torch(es).

Is your code incremental or absolute?

Regards,
JCC

[idahoflyfisher]

Can you delete all but the first F20 (feed speed) and try that? I just looked at some of my oxy code and I only add more than one F if I am changing speeds for varying thickness. It may be what is troubling your torch. Aren't those problems annoying?

WSS

Hadn't thought of that, just figured sheetcam knew what it was doing outputting code, but then again computers are only as smart as the operator. I'll try that tomorrow and see if it helps. Thanks for the idea, and yes, those type of problems are VERY annoying

[idahoflyfisher]

Sir,

In looking at your first line, G1 Y7.628 Z.625 F20:

This is linear interpolation: in moving Y 7.628 you are asking for Z to move +.625 ???
I don't understand why there is any Z motion command with oxyfuel cutting? Usually the operator manually controls the height by looking at the torch(es).

Is your code incremental or absolute?

Regards,
JCC

I could control the height manually, but why not get everything figured out so I don't HAVE to babysit the machine all the time? Code is all absolute.

[najnielkp]

how is the oxy fuel torch height being controlled?is it a capacitive ring sensor?

[idahoflyfisher]

Here's a copy of my code... was working okay, lost the cut, picked it back up, then torch took a dive about line 0340. Re-referenced Z axis to get right height, started over. Got to line 0300, took a dive 4 times in a row, same spot every time. Ideas anyone?

N0000 (Filename: bar caps3.tap)
N0010 (Post processor: Mach3.scpost)
N0020 (Date: 28/03/2011)
N0030 G20 (Units: Inches)
N0040 G40 G90 G91.1
N0050 F1
N0060 (Part: bar caps)
N0070 (Operation: No Offset, 0, T2: Flame, 0.06 in kerf)
N0080 (Flame, 0.06 in kerf)
N0090 T2 M06 G43 H2
N0091 M09
N0100 G00 Z2.0000
N0110 X4.0300 Y0.2800
N0111 Z0.7500
N0112 M08
N0113 G04 P25
N0120 Z1.5000
N0121 M09
N0122 M07
N0120 Z1.5000
N0130 G01 Z0.7500 F15.0
N0140 Y0.7520 F20
N0150 G02 X3.6550 Y0.5000 Z0.62500 I-0.3750 J0.1530
N0160 G01 X0.9050
N0170 G02 X0.5000 Y0.9050 Z0.62500 I0.0000 J0.4050
N0180 G01 Y3.6550
N0190 G02 X0.9050 Y4.0600 Z0.62500 I0.4050 J-0.0000
N0200 G01 X3.6550
N0210 G02 X4.0600 Y3.6550 Z0.62500 I0.0000 J-0.4050
N0220 G01 Y0.9050
N0230 G03 X4.4650 Y0.5000 Z0.62500 I0.4050 J0.0000
N0240 G01 X7.2150
N0250 G03 X7.6200 Y0.9050 Z0.62500 I-0.0000 J0.4050
N0260 G01 Y3.6550
N0270 G03 X7.2150 Y4.0600 Z0.62500 I-0.4050 J-0.0000
N0280 G01 X4.4650
N0290 G03 X4.0900 Y3.8080 Z0.62500 I0.0000 J-0.4050
N0300 G01 X4.0300 Y4.3770
N0310 G02 X3.6550 Y4.1250 Z0.7500 I-0.3750 J0.1530
N0320 G01 X0.9050
N0330 G02 X0.5000 Y4.5300 Z0.7500 I0.0000 J0.4050
N0340 G01 Y7.2800
N0350 G02 X0.9050 Y7.6850 Z0.7500 I0.4050 J-0.0000
N0360 G01 X3.6550
N0370 G02 X4.0600 Y7.2800 Z0.7500 I0.0000 J-0.4050
N0380 G01 Y4.5300
N0390 G03 X4.4650 Y4.1250 Z0.7500 I0.4050 J0.0000
N0400 G01 X7.2150
N0410 G03 X7.6200 Y4.5300 Z0.7500 I-0.0000 J0.4050
N0420 G01 Y7.2800
N0430 G03 X7.2150 Y7.6850 Z0.7500 I-0.4050 J-0.0000
N0440 G01 X4.4650
N0450 G03 X4.0900 Y7.4330 Z0.7500 I0.0000 J-0.4050
N0460 G01 X4.0300 Y8.0020

[najnielkp]

try turning off thc. should be a button on the main screen. or try removing power to the thc . you dont need it when oxy fuel cutting.seems like you have electrical noise. you will still have to control the torch height during flame cutting. large plates are rarely flat, and will rise and fall during cutting.shift sideways too, but that is a different problem.

[restless1]

Just curious what version of mach3 do you have?

[najnielkp]

the latest version. the default plasma screenset. you are probably using the candcnc screenset with the brains and plugins enabled. anyway, on the default plasma screenset there is a button to toggle thc on off.

[idahoflyfisher]

try turning off thc. should be a button on the main screen. or try removing power to the thc . you dont need it when oxy fuel cutting.seems like you have electrical noise. you will still have to control the torch height during flame cutting. large plates are rarely flat, and will rise and fall during cutting.shift sideways too, but that is a different problem.

As I said earlier, i don't run the THC. There is a card for it in the control box that came from CandCNC, but that's as far as it ever got. Never hooked any cables for it, never hooked the external card, nothing. So I don't really think that the THC is the problem. I've clicked the button to turn the THC on, and it won't turn on, so I can't turn off what already isn't on. I may be way off, but that's how I see it.

True that large plates are rarely flat, however, when cutting from 3/8" to 1/2" from the top of the plate, that's not really an issue either. I haven't seen any plates that are that far from flat. If I ever get one that's that far off, I won't even put it on my table.

Thanks for the input.

[idahoflyfisher]

Just curious what version of mach3 do you have?

i'm running 3.042.040