Gcode went wrong

Today my first gcode program went wrong. I wanted to mill a simple rectangle contour by using the tool radius compensation.
The raw material dimensions were 57mm x 25mm and i wanted to mill it to 56mm x 24mm.
The path from point 2 to 3 to 4 went wrong, but i do not understand why. In the tool table i added a 10mm tool.
Tanks for any hint.

Gcode:
G21 G17 G64 G90
F56
G0 Z5
G0 X-2 Y-2
G41 T10
Z-10
G1 X0.5 Y0.5
G1 X0.5 Y24.5
G1 X56.5 Y24.5
G1 X56.5 Y0.5
G1 X0.5 Y0.5

My quick guess would be that you've called the T10 tool load after the G41 compensation has been turned on:


Cutter compensation uses the currently loaded tool to determine the correct offset from the intended path. By loading the tool after the compensation has been turned on the compensation may not 'know' what the new tool is and assumes it is whatever diameter was used up to the point it was turned on (in your case no tool was defined beforehand, so tool diameter would be zero).

Try calling tool T10 before calling G41 and see if that corrects the issue. Alternatively it looks like you can use G41 D10 as well. The D variable forces the compensation to use tool number 10 for every subsequent compensated move. More info here;

linuxcnc.org/docs/2.6/html/gcode/gcode.html#sec:G41-G42

Are you sure you wanted G41 and not G42?

It seems to me that you wanted the cutter to the left of the chosen path?

Isn't that what G41 does? From the manual:

To start cutter compensation to the left of the part profile, use G41. G41 starts cutter compensation to the left of the programmed line as viewed from the positive end of the axis perpendicular to the plane.

Based on the OPs picture it looks like his code started at point 1 and went clockwise around the part, G41 should have placed the cutter to the left as it went around the perimeter.

Edit: not so sure any more. The diagrams on this page make me think G42 might have been required rather than G41.

I don' t think cutter compensation is active and that the coordinate system is a bit off. G0 X-2 Y-2 would make a big dent in the corner with a 10mm tool before compensation is switched on. Not sure why compensation didn't activate, maybe lack of M6?

If a 10MM tool is loaded that program should have failed with an entry move error.
Axis shows the loaded tool at the bottom of the screen, I am not sure how the other interfaces display that information.