Author Topic: Post processor inserting G3 and G2  (Read 557 times)

Offline SaigonJohn

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Post processor inserting G3 and G2
« on: July 02, 2022, 05:02:13 am »
HI I am relatively new to CamBam and I am having problems with the post processor.
When I load the Gcode on Mach3 Plasma the visual display on mach3 shows lots of large circles which indicates to me that a G2 has been transposed for a G3 and vice versa.
I must be missing something in the post processor set up.
I can edit the g code and replace G2 or G3 with G1
Any advise would be greatly appreciated.
Thanks
John

Offline dh42

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Re: Post processor inserting G3 and G2
« Reply #1 on: July 02, 2022, 12:34:41 pm »
Hello

Welcome to the forum

When you get "crop circle" in Mach3 display, this can be related to two problems.

1) The arc center mode selected in CamBam is not the same that the one selected in Mach3 ; to solve that you must select a Mach3 post processor to produce your GCode ; the post processor contain the commands that will set the Mach3 arc mode to match the one used in CamBam. (to Match CamBam settings, in Mach3 you can also set this arc mode manually in general config, "Distance mode" must be set to "absolute" and "IJ mode" to "Inc")

http://www.cambam.info/doc/dw/1.0.0/cam/post-processor.html

2) depending if you're using Inches or mm two settings must be accorded to the units that are used. By default the values in Mach3 post processor are set for Inch users and are to small for mm users. (Minimum Arc Length and Maximum Arc Radius)

https://cambamcnc.com/forum/index.php?topic=9274.msg72490#msg72490

++
David

« Last Edit: July 02, 2022, 12:40:25 pm by dh42 »

Offline pixelmaker

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Re: Post processor inserting G3 and G2
« Reply #2 on: July 02, 2022, 12:38:31 pm »
hello John

3) also possible:
In the postprocessor used, change the value for Minimum Arc Length to a larger value.
By default, the value is at 0.0001
Try 0.001 or if this is not enough 0.01.

If arcs are shorter than the specified value, a short straight line is output instead.
If the control software cannot work with these short arcs, these circles are created instead of the arc.
Don't forget to save the PP and do a reload.

ralf

Offline dh42

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Re: Post processor inserting G3 and G2
« Reply #3 on: July 02, 2022, 12:41:30 pm »
Hello Ralf,

Yes it is the 2) in my reply ;)

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David

Offline pixelmaker

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Re: Post processor inserting G3 and G2
« Reply #4 on: July 02, 2022, 15:35:38 pm »
Hello David, I hope you are well.

Your number 2 shows only with inch the possibility of too small values. But I know controllers like WinPCNC that can't handle such small values at all. Even if I work in millimeters I get the circles with the default setting of 0.0001 mm.

Offline SaigonJohn

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Re: Post processor inserting G3 and G2
« Reply #5 on: July 03, 2022, 04:45:09 am »
Hi David,

Thanks very much for your help. Greatly appreciated. I will investigate these two ideas, I'm sure you will be spot on.
Regards
John


Hello

Welcome to the forum

When you get "crop circle" in Mach3 display, this can be related to two problems.

1) The arc center mode selected in CamBam is not the same that the one selected in Mach3 ; to solve that you must select a Mach3 post processor to produce your GCode ; the post processor contain the commands that will set the Mach3 arc mode to match the one used in CamBam. (to Match CamBam settings, in Mach3 you can also set this arc mode manually in general config, "Distance mode" must be set to "absolute" and "IJ mode" to "Inc")

http://www.cambam.info/doc/dw/1.0.0/cam/post-processor.html

2) depending if you're using Inches or mm two settings must be accorded to the units that are used. By default the values in Mach3 post processor are set for Inch users and are to small for mm users. (Minimum Arc Length and Maximum Arc Radius)

https://cambamcnc.com/forum/index.php?topic=9274.msg72490#msg72490

++
David