2.75in RC Plane Spinner

This is an update to thing: 23936 (http://www.thingiverse.com/thing:23936). Essentially the same design but with a smaller outer diameter (2.75" vs 3") and some small vanes to help with motor cooling. I noticed that my batteries were getting pretty hot after doing 3D maneuvers. I noticed that the spinner is almost the same diameter as the inner opening of the cowling.

This design update is intended to try and remedy this. Haven't printed it out yet, but will soon.