Gcode Arcs

 I think that I am getting this, finally.

I started with th example and some graph paper.

%
g1 g20 g40 f500
g0 x0 y0 f500
g0 y1 f500
g0 y0 f500
g0 x-1 f500
g1 x1 f500
g1 x0
g1 y-1 f500
g0 x0 y1 f500

g2 x1 y0 i0 j-1 f500
g2 x0 y-1 i-1 j0 f500
g1 x0 y0 f250
m2
%

No, I am not cutting 2500 ipm.  That might work on air, who knows?  But the backplot feature of linuxCNC was taking forever.  I altered MAX_VELOCITY in the config file.  I am running linuxCNC in VirtualBox.

The first G2 made a 90 degree arc; the two g2 made another 90 degree arc.  If this does not seem that hard that it should have taken hours to figure out, you have more working brain cells than me.  The next step is making an arc that is only part of a 10" circle.

I am sure there is a way to do a screenshot in linux, but I am not even sure what GUI this is: