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 wi