I've been trying to print a file from a brain gear from Thingiverse, but the gear needs to be rotated to sit on one end. I'm doing that in Sketchup. I've installed the .stl import and export extension, and I can get the gear into Sketchup and rotate it. The gear has holes around its middle in addition to the big hole thru. One curious thing: the gear comes into Sketchup below the Z=0 plane,by gutenburg_2014 - Slic3r