Bridging bug

Slic3r Asked me to update to the stable 1.1.7 version, so I did (64 bit windows). Previous versions had suffered a problem whereby some thin vertical walls were not filled. This version does not create a solid base when bridging. See STL and resulting G file. When set for 50% fill (3 solid base, 4 solid top layers), the top of the square tube is bridged with a 50% infill rather than a solid base.

Dave

I think that part would benefit from being printed upright (as attached)

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Waitaki 3D Printer

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waitaki
I think that part would benefit from being printed upright (as attached)

Well, even if that were so, it does not alter the fact that the bridging on the top of the square tube should have had a solid base. The part has a mechanical function, and your suggested orientation would make it too weak. As you will be aware, printed parts are significantly weaker in the Z direction than in the XY direction due to layer bonding being weaker than continuous threads, and this must be taken into account for functional designs when deciding on the print orientation. A square pole printed lying down will be much harder to snap than the same pole printed upright (try it). If printed with your orientation it will be easy to snap the round platform from the tube of my design because that involves splitting layers apart, while with my orientation does not. It is a motor mount designed for a quadcopter using square aluminium arms, and with my orientation there will be no forces acting to sheer apart the layers, and additionally the layers will be held in compression by the tube & motor mounting bolts.

As an aside, I have found that ABS parts become quite a bit stronger if given a quick rub or dousing with a generous amount of acetone. The acetone soaks partially between the layers and acts as a solvent cement to bond the layers together. Acetone vapour treatment may work better, I haven't tried.

Dave

Yeah, true enough Dave. Have you tried an earlier version of slic3r - I've been using 0.97 lately because of the strange behaviour of later versions.

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_______________________________________
Waitaki 3D Printer

Quote
waitaki
Yeah, true enough Dave. Have you tried an earlier version of slic3r - I've been using 0.97 lately because of the strange behaviour of later versions.

No, but it is a good suggestion - I'll try it over the weekend. I ended up printing the part using a solid infill (the increase in weight was insignificant).

Dave