I’ve exported a bunch of Easel projects as gcode and have been looking at the files in a text editor to better understand what-does-what. Mostly I’m doing this to understand why my X-Carve seems so much happier running the Easel code than the Fusion360 CAM code I’ve fed it. One thing that I’ve noticed in the Easel code is a conspicuous lack of any G2 or G3 commands. Everything is a G1 “linear move” command. I’m wondering why? GRBL appears to fully support arcs and certainly for pocketing circles in Aluminum, it seems like using helical arcs would be “just the thing”.
Are they not used because they don’t work on our machines, or just to make the GCode easier to produce, or something else?
[Edit] I just found the Easel gcode spec which explicitly calls out that Arcs must be linearized. I’d still like to know why though, since Grbl supports them.
The early versions of Grbl did not support arcs but the recent versions support arcs just fine.
See this I realized I have never seen a g2 command in any of my code. I use vcarve and my post processor is set up to support archs using G2 and G3.
I just checked it out and it also outputs everything as G1 commands.
So as a FYI for VCarve users:
A bit of research shows that v-carve will only output ARC commands for segments made from arc types, as opposed to lines or bezier curves. I didn’t even know that arcs and Bezier curves were different before this. Working with one of my files it seems somehow all my circles got converted to benzier curves at some point. I am not sure how as when you make a new circle it is as an arc. It must happen when I edit it somehow?
You can convert an individual segment back to an arc by selecting the and right mouse click to call up the menu. Or convert an entire object by using the “Fit curves to selected objects” function.