Strange slic3r bridging pattern

I've printed a couple of parts with a short wide bridge, and was somewhat surprised to see the bridging pattern used. Here is a photo of the underside of the piece:



It appears that slic3r has printed "in the gap" instead of starting each bridging thread over one of the supports and ending over the other support. Which makes it all the more surprising that the bridge has worked quite well.

Has anyone else seen this?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

David,
What slic3r version are you using?, I have just moved to 1.1.1-experimental, one of the bug fixes was "Bridge angle detection was failing in many cases (thanks ledvinap for patches and debugging) " .
I reprinted your little test piece and I must say it's the best result I've seen. I am using all of the suggested settings from Ian that he posted a few days ago and so far I am really happy.
I am reprinting x-carrage-big slot at the moment so it will be interesting to see the results.

Hope that helps
Paul

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appjaws - Core XYUV Duet Ethernet Duex5
firmware 3.1.1 Web Interface 3.1.1
Ormerod 1-converted to laser engraver, Duet wifi
OpenSCAD version 2020.07
slic3r-1.3.0, Simplify3D 4.1.2, Cura-4.4.1

I was using slic3r 1.0.1. I've just upgraded to 1.1.1 and I get the same bridging pattern.

Looking at the gcode, I find that it is trying to do a proper bridge after all, however the loops at the ends are ending up just inside the gap instead of just outside.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
I was using slic3r 1.0.1. I've just upgraded to 1.1.1 and I get the same bridging pattern.

Looking at the gcode, I find that it is trying to do a proper bridge after all, however the loops at the ends are ending up just inside the gap instead of just outside.

I've seen that happen as well. I think I fixed it by setting the bridging speed really low (15mm/s), but I've not run any tests to be certain.

Dave
(#106)