Full circle arc with offset problem?

Hi
I'm currently developing my Qcad CAM config and have a problem with some but not all full circle arcs with offset.
When I remove the offset all is fine.

In the following line N60 is a no-show with no error?

In the following which is a cut from the outside appears OK.

Any thing I've missed ?

srl

Here are two screenshots.










srl

On 2.8 pre it will error "Arc move in concave corner cannot be reached by the tool without gouging."

Rick G

Here is a YouTube showing the problem and the importance of arc in and arc out with offset cutting.




srl

I believe it is your exit move that causes the problem, with it there is an error, below does not error out. Have you tried modifying the move to avoid the gouge?

S20001 M3
G00 Z100
X109.2826 Y40.1466
Z20
G42.1 D3.17
G02 X117.2813 Y40 Z2.6 I3.9993 J-0.0733 F400
G02 X117.2813 Y40 I-27.2813 J0 (problem here. add P2 and its fine)
;G02 X109.2826 Y39.8534 Z20 I-3.9993 J-0.0733
G40
G01 X113.282 Y39.9267
G00 Z100
M30

Rick G

Hi Rick
I'm running mm-sim and have no gouging errors as you can see above. arc in and out is the perfect solution for offset cutting. Its that nothing happens with line N60 then in the second file all is fine.

srl

Seams to me this discrepancy has come up before with inch, metric , tool table, etc.

I find that I get similar results as you do when running the axis mm sim BUT when running the AXIS sim error codes are generated.

Rick G

It appears that if the [TRAJ] section of the ini file contains...
LINEAR_UNITS = mm

The complete move is not made and no error code is issued.

However if the [TRAJ] section of the ini file contains...
LINEAR_UNITS = inch
An error code is generated.

Rick G

Change the cutter compensation back to a 1/8 bit. So the D value after G42.1 is .125 instead of 3.17 in metric.
The next move is still missing here using axis.ini.

srl

After reading the Gcode guide I removed the G2 and X -Y as they had not changed value.
Still no joy with line N60.
srl