Arc Tolerance

It is in the 2.7 docs Getting Started Guide.

www.linuxcnc.org/docs/2.7/html/getting-s...dating-linuxcnc.html

JT

I've just converted my Sherline lathe to CNC and my second test ngc already gave me this "Arc radius to small to reach end point". It is all about arc accuracy and I do not see where the error in g-code is. I've drafted cutting line in CAD with 0.0000 tolerance in mm and all looks good.
Anyhow ... as I've found this thread I've finally upgraded my old Ubuntu which was running with no upgrades for few years. As explained in this thread, patch to fix the tolerance issue is added in axis 2.7 and I am running fresh installation of 2.7.5. As soon as I've started Axis and opened the same ngc file I've got the same error.
As I am just Linux user and have no much in depth knowledge I am not eve sure where this 'patch' is located as I wanted to see what is the tolerance now.
My lathe is metric lathe. G-code generated defines arc with X Z R, not X Z I K, for example. It is SolidCAM and I even couldn't find a way that I get 'typical' arc with X Z I K

G2 X5.575 Z-14.808 R1.027

I was using custom built CNC machine for few year and EMC but never encountered an issue with arc tolerance.

Any input here is appreciated.

It looks like I found the 'problem'. It was the difference in having G7 and G8 mode.

As G-Code generated had to be modified I've made a mistake by adding line

G18 G7

And later

G18 G8

So second line was 'extra' and I've deleted it. GCode loaded fine after this change. :silly:

For the image uploaded can setting arc tolerance_mm value will solve my problem, or is it a G-code error?
The possibility of the latter being true is limited as I have tested my G-code on the online g-code simulator, and I can see exactly what I have drawn.

I have tried in my 2.7.0~pre7 ini configuration file, to set the value TOLERANCE_MM = 0.2, and still, I'm getting the same error.

On my laptop, I'm using the linuxcnc-mirror-reverse branch.

The code on the line is G03X-17.086Y17.698I-16.918J.66.

The distance mode is G91. Thank You.

Kunal.

Can you get your CAM software to output more places of decimals?

Yes, maybe. Trust me it is easier to get solutions here than from the cam software support. I will reply back in case I face any difficulty. Thank you.