Mini-T beams by Makerbeam
by Luis, published
This is created from the specs Makerbeam posted on Scribd. It is 40 mm tall but you can modify the sketchup file to the 10cm (100mm) that Makerbeam beams will be avaiable in.
UPDATE: Uploaded a 10cm beam in .stl format.
I included the DXF file I created from the PDF, extruded in Sketchup and exported to STL. The CMB file is for Dimension printers. I don't have my Makerbot up yet but plan to print these when its calibrated.