Here are the up to date Inkscape and Openscad files:
For the next example I'm going to make a hollow sphere and use the perforate module to make holes in it.
I made two circles in Inkscape one smaller than the other for my desired wall thickness :
Then I used Path>difference to make a ring:
Next I made a rectangle and used Path>difference again to cut it in half:
Then I added a star on layer2 for the perforation design:
I then converted both objects to paths, added more nodes, made them lines and exported the file as a dxf14 file to import into OpenScad. In OpenScad I used rotate extrude on the half circle on layer 1 to make the hollow sphere and the star on layer 2 with the perforate module:
As soon as I had the star pattern lined up on the sphere where I wanted it I used difference to subtract the perforate layer from the rotate extrude layer:
Then I rendered it and saved the stl file and was ready to slice it for printing:
