Beam
thingiverse
I designed this a while back and only just got around to posting it. It can support at least 1000 pounds. Instructions Print on standard resolution with 5% infill. Do not use raft or support. Also, only print the beam upright.
Download Model from thingiverse
With this file you will be able to print Beam with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Beam.