Development Step #3 – Building the prototype
o Approach.
I got ideas about the design from the visual effects industry, more specifically animatronics:
https://www.youtube.com/watch?v=6jqvu _MQ5pc
o Learning Experience.
The main function of the prototype is to position servos, which are moving an semi-spherical object on the x and y axis.
For the rotational joints I used parts from lego-robots called Bionicle.
They allow rotation in a big diapason. One of the axis can take up to 280 degrees rotaon, on the other axis only 60-80, that is why I had do position them in the right servo order so that I take advantage of the maximum
diapason.
For the other moving parts I used bolts, which go in the wooded parts, through plastic straws, for extra strength since they are quite fragile.
o Result.
After several days I finally managed to make it work, at least on theory.
In order to fit the camera inside of the sphere, which actually is a plastic bowl, I had to take it apart and use
only the board itself.
I used the strip board to connect all the grounds and the 5V. One servo is connected to pin 12 and the other one to pin 13.
o Sources.
https://www.youtube.com/watch?v=6jqvu _MQ5pc
Development Step #4 – Raspberry Pi Cases
o Approach.
Raspberry Pi is a great way to replace a computer as the image processing unit. That is why I decided to use it for this project. I am going to use technical drawings as a guideline for my design.
I got my hands on:
Raspberry Pi Zero
and
Raspberry Pi 3B
If the processing power of the raspberry zero is not enough, then I would switch to Raspberry Pi 3B. I read that it is highly recommended to make a casing for the Raspberry since it is not so durable.
o Learning Experience.
I started by looking at the technical drawing of both from the official website.
https://www.raspberrypi.org/
I made case according to the official dimensions mentioned in the technical drawings.
I also planned some extra space on the boards for heatsink, to reduce temperatures.
o Result.
This is the first test with the laser cuer. I used an acrylic material instead of wood. The issue with the first test was
that I did it for a 3mm plate and it turned out to be 4mm.
After some corrections It finally fit.
The Outcome:
Raspberry Pi 3B
Raspberry Pi Zero
The final problem was that the Raspberry, unlike Arduino, is having mounting holes of M2.5 Size. I looked everywhere
in Enschede and I couldn’t find any. That is why I had to order online.
o Sources.
https://www.raspberrypi.org/
https://www.raspberrypi.org/documentation/hardware/raspberrypi/mechanical/REA DME.md
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