I copied Robert Lussow's defog fan install. I'm using two 3" computer fans. I fabricated support rings and fit them to the forward upper fuselage. I then cut the two 3" holes. It would have been better to cut these holes before assembly of the forward fuselage but such is the way of airplane modifications. I ended up cutting the two 3" holes in the top skin with an undersized hole saw. I then used a durm sander on my drill followed by a larger Scotchbrite wheel on my die grinder to finish it all off. I need to get some #8 screws of the appropriate length and will then attach the support plates.
