QCAD.org Forum

I sent in a drawing to a laser cutter shop and they claimed that the drawing has an open contour. They even sent a screenshot of their analysing tool spotting the location where the faulty contour occurs. How can I figure out the exact circumstances?



I'm posting their findings and the DXF also.



I already amended a split line in the lower right section but I cannot find the open contour.
It seems that the magnifying glass sits right over the actual spot of failure. Not to mix up with the red "X" in the origin arrows.

Simplest I can think of:
Double-click an entity. This selects all connected entities. Where the selection stops, you'll find a gap.

You might want to create a polyline which guarantees that the contour is closed (right click on entity > Auto Create Polyline).

Note: such gaps are an indication that the contour was not properly constructed. There are very likely unwanted imprecisions.

Thanks for the hint with the double-click. This reveals indeed a spot of discontinuity. But theses spots must have "creeped in" so to say during time of construction history. Zooming in also spots the situation. There is a minimal gap between the arc ends and the line ends.

The drawing has a few more problems like gaps, duplicates and zero length entities ........

run the "Detect zero length entities" tool - 8? Delete them.
launch the "Polyline from segments" tool with a tolerance of 0.1 / simplify - that will close gaps.
if your laser cutter shop can't handle polylines - explode afterward the polyline.

I was able to apply the zero length detection tool. Also the "Polyline from segements" was applicable.

How can I join the different polylines now to one cohesive?

EDIT: seems I got it: after I had solved all discontinuities I could create a polyline from segments since the selection then covered all segments.

Super helpful post this got me out of a jam today when I was attempting another fill.
I was getting a "loop not closed at point xx yy" error.