Some time ago, one afternoon (as a susceptible citizen for the salvation of the planet), throwing some magazines and newspapers into the recycle bin I saw a broken plastic airplane toy thrown out of a bag. So I took out a four blade propeller and two engine lids (all of which were useless) in order to make a small fan for my computer desk, more like fun than functionality. Anyway with 5-10 euros I could have bought one ready from the Chinese but…. the point was to exercise the brain as well.
This is how the story of the desk fan begins.
Here are the first designs-adaptations-research. An old TRex 600 head bearing, an aluminum pipe piece from A/C car, a broken electric iron section, some TV antenna tubes, various screws, plexiglass pieces, a Weber carburetor float and lever assy, the two plastic engine caps, one electric motor 12v from an old car radio tape, a small rubber band and the propeller.
The construction was fun but …… .it was just the beginning for it to evolve.
At some point I saw an ad about a damaged Nitro engine from an RC car. Then it came to my mind to review the whole design of the fan and make something different but out of scrap materials. Eventually the engine from the car was rejected as an option because the exhaust outlet was upside down, meaning it would look at the propeller. So I decided that the best solution would be to pick a plane engine and focus on research.
Advertise on aeromodellimg.gr (Greek forum) and the engine (a 40 MAGNUM GP) was found and bought at a symbolic price by a Greek air modeler Constantine, who along with the engine sent 2 propellers and 2 spinners. The modelers finally have a big and good heart. So the old bags were reopened and all the scrap aluminum I had left over from previous builds was re-assembled to begin the study, design and puzzle of future construction. The propeller rotation would give a 12 V motor from the car's kilometer dial gauge.
It was mounted in an aluminum cylinder parts by a brake master cylinder and with a simple rubber band moved the crankshaft and the propeller. As later, however, the tests showed that it did not have the proper strength and warmed up after 7-10 minutes.
A change of design and an old videocassete recorder gave his motor (with enough torque and 2200 speeds/min) but due to its size it no longer fit the aluminum cylinder. Not to be outdone, an old useless electric petrol pump from Renault Twingo cannibalized. The cylindrical outer shell was cut, polished, and covered the 12v motor. The classic rubber band from the motor to the propeller, was now replaced by a red O-Ring.
The support base of the whole construction was also a problem. I thought it would be great to have the whole machine, propeller and drivetrain (motor 12v) give the impression of being "in the air", so I cut some pieces of plexiglass to make an arm to screw the engine with its accessories. 4 aluminum plugs of unknown origin were employed to secure the plexiglass sections and 2 pieces of seat belt pretensioners for the so-called base legs. By this way I had now stabilized the whole set. The piston and cylinder sleeve were then removed to allow the crank to move freely.
