30 mm to 40 mm fan adaptor

I printed off a 2 in 1 fan duct for my E3D V6 (http://www.thingiverse.com/thing:839620) which was made for a 40 mm fan, I only had a 30 mm fan so while I waited for one to arrive I knocked up this adaptor for a 30 mm fan to sit on a 40 mm base. It works well enough; I used supports as the 30 mm mount overhangs (I didn't really consider that during design) but the support material broke away easily enough and left a useful piece. The photo is of the thing attached to the 2 in 1 fan duct with th