Oh I love that kind of silly Rube Goldberg stuff...find attached a crawlspace ventilation fan I put together after our addition was built. It originally was a temporary measure for when I found a commercial grade fan to use. It worked so well (silly as it looks) I just left it that way. It's over 10yrs later now.
About every 3-4yrs or so I have to clean the fan & lube the bushings and about every 5yrs sometimes I have to replace it. I go to the thrift store & buy another fan for $2.00 & good for another 5yrs!