Light Diffuser for Mr. Beams Motion Light

The default diffuser is just a plastic panel; it has a harsh and inefficient pattern for general light. It was really intended to light a foot-path, but I wanted generally diffuse light. This diffuser spreads light a bit more evenly.

Model MB720, like this on Amazon:
http://www.amazon.com/gp/product/B002FCGI8Y/ref=wms_ohs_product?ie=UTF8&psc=1

I included the 123dx source so you can remix easily. I was thinking to try meshmix with those twisty vases they featured on Thingiverse's main page.