Changing parameter gcode_arcs from 0 to 1 does not work

Hello

I tried to use the G2/G3 code. To switch on this feature I exported the config.ini file and changed the parameter gcode_arcs from 0 to 1 and imprted the saved file back to Slic3r.
Whatever I saved the three settings or not, the exported g-code does not include any G2 or G3 instructions. I tried that with differend variants of STL export parameter.

At the end of a g-code file Slic3r put the parameters of the config.ini. In each file the parameter gcode_arcs was 0.

How can I change the that parapeter to 1 to use the G2/G3 g-code?


Thanks

Using arcs is non-trivial and I don't believe that the release version of Slic3r can presently do it, though IIUC there is some experimental versions that makes the attempt (BICBW). The problem is that the STL format cannot describe arcs - circles and arcs are always approximated by multiple short straight sections in the STL itself. To output arcs the slicing software will need to look for such short sections and try to calculate the arc that they are approximating - which could of course be a section of an ellipse rather than a circle. In any case it is completely impossible to determine whether an STL section that describes (say) a small 20 side polygon is from the model containing a 20 side polygon or is approximating a circle. A far better way would be to not use STL files for input, but use a format that that can describe arcs. The issue there is that there is no such format that all popular CAD software can generate, so we must first await a suitable open standard for 3D models to be widely adopted. The other point is that not many FFF printer controllers implement the G2 or G3 functions, so even if you got the appropriate G code there is a good chance hat it would not work on your printer.

Dave

Edited 1 time(s). Last edit at 04/12/2016 07:36AM by dmould.