1.4 Development Steps this week. #3 #4

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 rota􀢢on, 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 cu􀂂er. 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