I can’t help but wonder how they can make a profit.
Figure 11 shows the slip ring assembly installed on
the main axle of the wheel. Refer to the schematic for the
wiring. Two of the conductors were used for the serial
digital signals from the Arduino to the LED controller
Actually, I think I spent more time playing around with
different lighting patterns than anything else in this project.
I had fun generating a number of sketches that produced
hypnotizing patterns of colored lights. It was hard to stop
playing with it. (BTW, the Arduino code is available at the
I won’t go into any detail about the code here
because it’s pretty simple and most of it was “example
code” for the discontinued LED strips from the Shack.
SparkFun and Adafruit have much better addressable LED
strips now, plus example code to run them.
Bells and Whistles, Phase 2
I thought that adding the lights was the end of the
project until one evening when I was proudly showing it
to my wife, she commented, “That’s real nice but what it
needs are some cute little characters riding in the cars.”
Garf! Unfortunately, she was right. So, I headed to the toy
store and found eight properly-sized candidates, including
I glued them down in the front of the cars so you
could see their faces as they went round and round. The
only problem now was that the cars were tilted forward,
not level. I hate it when things are not level. So, I added a
number of hefty steel nuts in the rear of each car until
they were all perfectly flat. Success!
I started the motor and the “cute” little characters
went half way around and promptly came to a dead stop.
What the heck? After an intensive 10 minute failure mode
analysis, I discovered the core problem. Each car now
weighed a different amount because of the different sizes
of the characters and quantity of steel nuts. This situation
unbalanced the big wheel and overwhelmed the torque of
the Erector motor. The answer: more steel nuts. Finally, it
was perfectly balanced and rotated very smoothly. Done,
done, and done!
A short low resolution video of Big Bird taking a ride
can be seen at http://youtu.be/K5JuUVva_QQ.
All my friends were impressed with the operation and
the kids were mesmerized by the flashing lights and
carnival music. It was well worth the effort. However, my
wife still had one more thing to say about the project. “I
love how it turned out,” she said, “but where are you
going to find the room to store it?”
It was fun working again with the Erector Set metal
girders, axles, and especially the motor. It’s sad that sets
like these are not economically feasible anymore. I think
that kids are missing out with the snap together, no-thinking-required plastic kits of today. Fortunately, vintage
Erector sets are still available.
I think that buying one and building a project like the
Ferris wheel or a Bascule bridge with your kids or
grandkids would be a kick. I hope you will truly consider
▼▼▼▼ ▼ ▼▼ ▼ ▼▼▼▼ ▼▼ ▼
FIGURE 11. A six-conductor slip ring assembly from China
transmits power and data to the LEDs on the rotating wheel.
April 2017 39