This is the result of an experiment to make something that flies from LEGO only.
Using the buggy motor and speeding it up by a factor 3, this rotor actually develops more thrust than its weight (about 20 grams). It can therefore free itself from the drive axis and then lifts off to about half a meter. I decided not to provide build instructions, as the rotation speed well above 1000 rpm seems dangerous. See also the warning in the video clip AirborneLEGO on YouTube. Particularly, there is the risk that parts come off.
Thanks for your response Rtas 'Vadum!
In my experience friction spoils it with extreme gear ratios. However i am curious to see what your drive train would do to this propeller. Can you please give it a try if you have the parts and let us know?
October 24, 2009
Only a factor of 3? I have a the same motor as you that I have calculated to spin at ~700 rpm. My Fan o' Death has a gearbox that multiplies the speed by 25. Theoretically, I could have something that spins at 17,500 rpm. It could definitely be better.