How fit the MIOs in the carrousel, making easier their exit, and without
turning the mechanics of the carrousel to difficult ?
The prototypes we tested made us choose to put 6 MIOs in the carrousel
(and not 8 as we initially thought) for dimension reasons. Indeed, with a PIC board (or a
68HC11), the servomotors, the wheels, the sensors, the batteries, 8 MIOs will
make them too small and difficult to build.
Instead of turning the carrousel to make the MIOs leave, a more simple
way to put the MIOs into the carrousel is decided :
MIOs in the carrousel (view from above)
The previous diagram shows the MIOs inside the carrousel on the starting area.
The movement of the MIOs at the start is shown by the arrows.
The MIOs are drawn with their maximal size (a cube of 15cm side).
We can see on the diagram that there is enough room in the carrousel to put
its locomotion system.
The choice of servo-motors has been validated (see the documents
on servo-motors in the Technical DB).
The wheels were found on 50 Francs toys (see the characteristics
in the technical DB in the page
related to the MIOs mechanics).
These wheels are very adhesive, they are small enough to fit in the MIO and
big enough to provided an adequate speed.
The assembling of the wheels on the servo-motors is in the
Toy from which the wheel have been taken
For our MIOs, we choose cheap batteries. These are Ni-Ca accumulators of 600 mA
found in supermarkets. We make a few loaded tests and we talk about it soon in the
The frame is built with aluminium bars, servo-motors and 2 wheels,
and in the front a small ball. A description of the realization of the frame is in
the technical DB. To test the frame in movement,
a test board with a PIC is put on it.
The final frame will have a prop under the ball to increase the
ground clearance to 2cm. Our calculation for these MIOs give us a
ground clearance of 1cm at least to be able to cross the hill. 2cm will then be OK.
Climbing the hill
|Regarding the tests we made on this MIO, the best manoeuvrability and the best
adherence is obtained with a propulsion from the back of the
And it climbs the hill of more than 60%!!!