Carpc project - the case

 http://pacmans-revenge.blogspot.com/2018/04/carpc-project-case.html?m=1

 

Monday, April 16, 2018

Carpc project - the case

I recently uploaded a new video to show my custom-made carpc based on a Raspberry Pi. In the video, I had to leave a lot of information out for the sake of runtime, so, I decided to write a little series of posts to explore thoughts and ideas about this project.

This episode is about the case.

Disclaimer (sort of):
Be aware that this post is not self-contained. If you haven't seen the video, you probably won't get much out of this reading. Also, this is not a tutorial on how to build a carpc like the one I made. For that, I'd need much more time and space. I just want to document the thought process behind a few hardware and software choices, share some techno-ramblings, and provide you with some links to get you started using the components I used.

Have you ever modified your car with custom electronics? Are you planning to hack a Raspberry Pi into a device that was not intended to be modified? Have you ever started a simple project (such as adding music to your car), and somehow turned it into a huge, titanic undertaking?

The case

 

Final design files.
And then it hit me.
With this project, my car will become a wild mess of tangled wires. Shaking my head in horror, I decided to do something about it, and design a custom 3D printed plastic enclosure for the carpc.

Now, I'm not an industrial designer, so this case design required a good dose of improvisation and trial and error. I also fought fiercely against the (small) tolerances of the 3d-print shop, and discovered with great disappointment that designing a 12.5mm wide part does not mean the part will be exactly 12.5mm wide. This realization bit pretty hard the moment I started designing parts to be slotted into one another. Experience, experience...

3D-printed case parts.
So, In order to take measurements and get the proportions right, I've made a crude mock-up in paper (actually, SEVEN crude mock-ups in paper. It's amazing how often a millimetre can make the difference between two parts aligning with each other and one part ramming itself into the other one...). Then, I had to choose a 3D CAD to input my final design. Being a complete noob in this field, I faced quite some problems in becoming proficient in any of the popular CADs for Linux, from FreeCAD (still a mystery to me) to Blender (full-featured, but with a steep learning curve). In the end, I settled on Sketchup, and designed the whole thing under Windows, starting from a single rectangle and extruding the entire structure volume by volume. I'm sure this is not how it's done, but the result holds in place, so I call it a success.

PS: I had to shave a few millimetres off the corners of the base to make it fit the ash tray cavity, because no matters how accurate your paper model is. It isn't.

Have fun,
Kradion.
at

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