QCAD.org Forum

Hello! how do I convert an arc to a straight line.


context: My cnc machine has issues with small arcs, it considers the radius too small, but it has no problem with small straight lines. its a whole lot of work to convert small arcs to lines manually, this there a way of converting a selection of arcs into straight lines?

The easiest way I can think of (worth it if you have a lot of these arcs):

- Select all arcs with a small radius using the selection filter (View > Selection Filter) for example with Arcs, Radius, < (less than), 0.1.
- Isolate the selection on a separate layer (e.g. Layer > Add layer with Move selection to new layer checked).
- Convert all arcs to polylines: Draw > Polyline > Polyline from selection, this will deselect your entities as your arcs are replaced by polylines.
- Select all entities on the new layer again (Layer > Select Layer Entities).
- Draw > Polyline > Arc to Line Segments.
- Explode the polylines: Modify > Explode.
- Optional: move selection back to original layer.

Andrew,

The site https://www.qcad.org/ was not reachable for a longer period today ... Except https://qcad.org/doc/...

In the light of that event ...
I find it curious that this post is almost an exact copy of a former post.
Even QCAD is misspelled in both. "this there a way" is the same typo.
The only difference is the sign off.

See: Hello how do I convert an arc to a straight line on Quad by hannaconner.


ryleybob,
Even small arcs by radius may have a larger sweep angle.
Replacing such with a line segment from start to end may result in a jagged path.

Are you working in inches or in mm?
A typical CNC driver can handle both.
For mm the numbers are 25.4 times larger.

Please specify how small or short that it becomes a problem for your CNC.
Perhaps you could specify the sort, mark and model of your driver and setup.

Are you using QCAD/CAM?
Because that can interpolate arcs on export.

Regards,
CVH

Thanks, CVH. The poster was a spammer indeed. And so was the other poster from July. Both deleted.