The Little Ferris Wheel
This is a picture of the (mini) Ferris wheel which was shown during
the HCC Days 2002 at Jaarbeurs in Utrecht.
I have also used this interface for this model, but this time for controlling
a stepper motor.
At startup the Ferris wheel assumes the initial position, and after a few
seconds the wheel rotates through 60 degrees. This is repeated five times
to allow riders to board. Following that, the wheel makes two full rotations.
To let riders off, the wheel repeats its pattern of 60 degree steps.
In the picture on the right you can see that the PCB interface and the
motor controller can each be mounted onto a Meccano Flat Plate #53a,
demonstrating that it is not necessary to mount these PCB's on a single mounting
plate. The longer ribbon cables allow mounting these PCB's about 100cm apart.
The stepper motor can be seen clearly in this picture. The reason I have
used a worm gear is that, in spite of its small size, the wheel was gaining
sufficient momentum to behave as a flywheel and force the stepper motor through
additional steps after power was cut off. But with a Worm #32 and a Pinion
#31 this problem was solved for the most part. To smooth out slight roughness
in the rotations I have installed a micro-switch which returns the Ferris
wheel to its initial position after every cycle. You can also see my homemade
adapter which bridges the 5mm output shaft of the motor with the 4mm bore
of the Worm.
That everyone enjoys the Ferris wheel can be seen in the faces
of these little Fischertechnic men sitting in the Meccano seats.
.GIF)