Drone Arm Parametric Design

I am new to quadcopter designs & was not sure what size I wanted my quadcopter to be. After looking at several designs, I decided to come up with a parametric Arm design so I could easily change some key dimensions of the arm & see how it looked visually put together. This is not a remix, but did use the wire channel idea from the Peon230 http://www.thingiverse.com/thing:629338. I made the ledges on each side of the arms 8 sided which has worked well for me in other designs adding strength with less plastic & in this case giving a channel for the wires to lay in also. There is also an option to make the arms flat in case you do not need that channel.

There are quite a few dimensions you can change for this design & I have included a PDF file showing the variables that may not be obvious from the description in the openscad file. You can use this as visual aid to see how different length arms, locations & rotations affect your design. Once you have it the way you want it, you c