LEGO helicopter rotor working demo's
May people have been inpired by LEO & LEGO to work on LEGO-realisations of very complicated mechanical structures such as as clocks and helicopter rotors. Leo also gives a very nice explanation of the working of helicopter blades. A very nice demonstration model that can only control the lift is the propperchopper on CMU's LEGO stuff This model can demonstrate lifting and landing because it is mounted on a balance. A complete model of a cobra helicopter with pneumatic control of both main and rear rotor blades (no cyclic control) has been created by Andrew Bisell and Steve Robinson .
First trial spring 2002
My son, Joep (now 14 years old) and I tried to find a new construction for the rotor. The result is still not good enough to be used a directable fan as Leo suggested for his design.
The orientation of the blades depends on the phase of the rotation. The orientation of the "wheel" in the middle is controlled by gears in a gyroscopically working support. The total lift of the blades can not be controlled in this construction. One idea is to use Leo's construction for vertically moving the central axis while preserving the transmission with a traction wheel.
The last picture of this design shows a detail of the rotor.
Needless to say that suggestions for improvements are very welcome.