The mechanical aspect of or device may appear simple besides the complexity of hardware but managing to make the blade turn while fueling it with 120W is a real challenge.
Here is a view of the draft used to propose the solution to the person who will make some pieces: The tree (in the center of the device), the base to support it (represented down and right to the device) and the piece that will hold the blade (at the left of the device).
To better understand it I colored several parts of the scheme.
In yellow is the pale bearing the leds, the gumstix, the fpga, memories etc.
In red is the part that will turn: the tree, the piece that will hold the blade and a part of the coding wheel.
In blue is the part that will stay: the base, the engine, the outside ring of the ball bearings and the second part of the coding wheel.
In green is the system of reduction (2:1) that links the engine and the tree. It will allow us to have a better torque.
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