Jerry: FWIW I just spent quite a while trying various methods to resolve this well known and oft discussed subject. I had used inkscape to generate a fairly complex lattice and used the "inkscape to openscad" extension to export a file to be used in OpenSCAD. That file could be used to generate a stl file with OpenSCAD but when I tried to then import it back into OpenSCAD it failed with errors similar to yours. Lots of trial and error netted no joy. To my surprise, however, while fooling around, I imported the stl into blender (2.69. it has some nice tools for analyzing stl). I didn't "fix"/change anything and at the end I luckily made the mistake of exporting it as stl and when I imported it back into OpenSCAD it worked! Tried it on two or three other items I had done similarly and had similar results. Doubt if it's a fix for everything but you might want to give it a try.

thanks, John. That is good to know. Will try it. -- Extra Ham Operator: K7AZJ Registered Linux User: 275424 Raspberry Pi and Arduino developer *The most exciting phrase to hear in science - the one that heralds new discoveries - is not "Eureka!" but "That's funny...".*- Isaac. Asimov On Mon, Jul 18, 2016 at 10:15 AM, John Tucker <jart3@verizon.net> wrote: > Jerry: > > FWIW I just spent quite a while trying various methods to resolve this well > known and oft discussed subject. I had used inkscape to generate a fairly > complex lattice and used the "inkscape to openscad" extension to export a > file > to be used in OpenSCAD. That file could be used to generate a stl file with > OpenSCAD but when I tried to then import it back into OpenSCAD it failed > with > errors similar to yours. > > Lots of trial and error netted no joy. To my surprise, however, while > fooling > around, I imported the stl into blender (2.69. it has some nice tools for > analyzing stl). I didn't "fix"/change anything and at the end I luckily > made > the mistake of exporting it as stl and when I imported it back into > OpenSCAD > it worked! > > Tried it on two or three other items I had done similarly and had similar > results. Doubt if it's a fix for everything but you might want to give it a > try. > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >