Semi Ducted Micro Frame (Cheese Frame)

This is a remix of [Phredie's great ducted micro frame](http://www.thingiverse.com/thing:1775891).

I made this after talking to a friend over at [quadcopter.at](http://quadrocopter.at/). He flew my whoop some days ago and we started to talk about improvements. So most of the changes I credit to [noctaro](https://www.youtube.com/user/zoomrpd).

I made the walls slightly thicker - my printer need needs at least 2 1/2 nozzle widths for the layers to stay together, otherwise they will peel easi