MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I tried lots of different versions ... even making ones with larger tabs with holes in them etc to keep the weight down. Unfortunately they were all too heavy. The default configuration in your SCAD file printed with no infill as you suggest seems to be the best solution. Is there a reason why the motor attachment arms are arched? I'm hypothesising that that's not the strongest way to do it?