G51 Scaling error about core HOT 1 CLOSED

Default scaling mode is Mach3 style:

"10.7.15 Scale factors G50 and G51
To define a scale factor which will be applied to an X, Y, Z, A, B, C, I & J word before it is
used program G51 X~ Y~ Z~ A~ B~ C~ where the X, Y, Z etc. words are the scale
factors for the given axes. These values are, of course, never themselves scaled.
It is not permitted to use unequal scale factors to produce elliptical arcs with G2 or G3.
To reset the scale factors of all axes to 1.0 program G50"

It can be switched off by commenting out #define MACH3_SCALING in gcode.c (line 43). IIRC that mode is the same as described in the link above, which has the following note:

"NOTE: In no case can an ellipse be generated using scaling."

Otherwise, it will only work if scaling is equal in All axes.

So this is, AFAIKT, the expected behaviour. If you have any example files which should work please share.

from core.