G2/G3 arc movements

Hello everybody,

I'm a proud owner of a Mendel90 since some weeks and just finished a laser attachment for it which replaces the extruder unit with a laser. I create my G-Code with Inkscape from vector images which gives me a set of G2 and G3 commands that somehow produce a strange behavior of Marlin. As soon as I send the commands the z-axis is moving in positive direction and nothing else happens. Did anyone of you try the arc movements with your printer and fix the issue? I've been searching the forum for quite some time but did not find any suitable answers.

Regards

Does Marlin officially support arc cutting using G2/G3? The gcode wiki page says you need to enable the SCARA option, but I've found references to earlier posts in the forum that says Marlin just coverts it multiple short straight segments so there isn't much advantage for arcs over straight movements other than less data needing to be transmitted.

I have also already been looking for "SCARA" but did not find anything. Even if Marlin would do the conversion I wouldn't bother because my problem is that I'm only getting the G2/G3 commands from my G-Code converter. I did not find a possibility so far to generate directly only the standard G1 commands.

So the best case for me would be that Marlin understands G2 and G3 regardless of a later conversion.

Cocoknight
can you paste a few lines of gcode with arc so I can test on my system.
In normal cnc zero is the top of the work and moving down is going negative which is the opposite of 3d printers

CRDU
If you look in Marlin code for Marlin_Main.cpp you will see the line "This firmware is a mashup between Sprinter and grbl."
GRBL is a cnc program that supports arc comands.
I have tried G2 And G3 arc comands in my generic marlin and both work.

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george4657
If you look in Marlin code for Marlin_Main.cpp you will see the line "This firmware is a mashup between Sprinter and grbl."
GRBL is a cnc program that supports arc comands.

I would never trust a semi-random header comment in source code that says it's a "mashup" of multiple other products to determine support. You have no idea when that comment was put there and what modifications have been made since it was done as it relates to what the original supported features of the previous products. This is talking in general and not specifically to arc support.

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I have tried G2 And G3 arc comands in my generic marlin and both work.

With that, another possibility is that the generated gcode was in radius format and it needs incremental, or vice versa. Seeing what code was attempted might help determine what's up.