In this project I was aiming to reproduce the common PC ATX "desktop" case but in miniature to fit a Raspberry Pi. My goals were to ensure all cabling exited the rear (like you'd expect on a normal PC) and that the Pi itself was fully accessible for any future project work. As per most of my builds this was using predominately recycled material.
My parts list for this are;
- The side of an old Dell PC case (which is made out of plastic)
- An old CD case
- A few small screws
- A couple of small misc bits of plastic salvaged from assorted recycling
- Raspberry Pi + cabling
- 2 LED's, resistors and wires
- Small sticky pads (used as feet)
- Superglue + bicarbonate of soda
- Spray paint + acrylic paints
- Some Milliput for filler/bonding
- Oscillating Multi-tool/cutter (for cutting/shaping)
- Multi-purpose rotary tool (e.g. Dremel) for fine cutting, shaping, sanding, finishing etc
- Soldering Iron (a multi-meter can also be useful but isn't essential)
- Screw driver
Step 1: Prototype and Sizing
First step was to work out how big to make the case. My desire was to have the case be approximately the right proportions as a desktop ATX case but in miniature. I started by measuring a few desktop cases I happened to have in the house (width, length, depth) and recorded these into a spreadsheet, then I took the averages of those to create a "typical" set of dimensions. This allowed me to then calculate ratios between the various dimensions, looking at it side-on, the width is the largest value, so I base lined on that and worked out the height is about 85% of the width, and the depth is about 44% of the width.
Next I worked out which was the critical dimension on the Pi. This was complicated by the port placements on the Pi, I needed to redirect the HDMI port from side of the Pi towards the rear, so I added a right angle HDMI adaptor to the Pi. This caused the height to be the most critical value - the case had to be able to accept the Pi + adaptor, using this measurement, I then scaled the other dimensions using the ratios mentioned above.
From this, I created a cardboard prototype to verify the sizes. You can see from the pictures, my first iteration did not account for the HDMI adaptor, and I ended up having to make the case a bit bigger (as shown by the extra cardboard on the 2 sides in the picture).
Step 2: Layout and Cutting
Once, I had my prototype, I expanded the it out to create a flat template and laid out the pieces I wanted to cut on my salvaged PC case side. Then I cut out the pieces. Note at this stage, I don't have a back for the case - that came later and was made a different way.
Step 3: Cutting Out the Window
I decided to make a window in the side so I could see the Raspberry Pi. I laid out a shape using masking tape to define where I wanted to cut. Both the window and CD were cut to size and then I simply glued the CD case inside to form the window. There was a bunch of clean up work necessary as the inside of the PC case had a lot of support members sitting proud of the internal side, which needed removing in order to fit he parts.
Step 4: Fitting the Case Together
With the pieces cut out, my next task was to glue it all together. I used superglue with bicarbonate of soda to form strong welds between the sides. I reused a curved chamfered edge the original case had to form a more interesting line around the bottom of the case. This worked well, but did require a fair amount of hand finishing to get the front part (in particular) to align, and then some filler (I used Milliput - as I was also able to use any excess as re-enforcement along the joints internally).
Once it was all assembled, I started the process of sanding and filing away rough edges/burs etc
Step 5: Sliding Drawer for the Raspberry Pi
In order to make access to the Raspberry Pi easier, I decide to mount the board on a "sliding drawer" which would allow the contents of the case to be slid in and out without disassembly. This was built by 3 pieces of scrap plastic left over, these were cut to size and glued in the same way as the main case. Once assembled, I tweaked the shape/size until it fit snugly. I gave the case a test spray paint at this point to see how it looked - I fully expected to redo this later, but just wanted to see how it was coming together at this point.
Step 6: Prototyping LEDs
Most cases have some activity LED's on the front. My first stage in implementing these was to prototype the wiring using a breadboard (as per the picture). I found a great reference resource here (https://projects.raspberrypi.org/en/projects/physi... for putting together simple LED patterns driven off the GPIO pins.
Later, I soldered all this together in order to make it fit in the case, but I wanted to verify the concept and get some basic Python code running first.
Step 7: Fitting the LEDs
Once the prototype was complete, I soldered all the components into place and glued the LED's into a small bracket I made from a scrap bit of plastic (I used a hot glue gun here - but superglue or UHU would've worked fine to). By mounting the LED's on a separate bracket, it allowed me to remove the whole circuit again if I needed to. A couple of holes were drilled to allow the LED's to poke through.
Step 8: Finishing Touches
- Added some feet using some sticky pads I had in my box of spare/random parts
- Made a Raspberry Pi logo (used masking tape to transfer the picture from the Raspberry Pi Magazine to a scrap piece of plastic, then carved the logo out using a dremel, finally painted in the details)
- (Re) spray painted the case
- Fixed the logo onto the side of the case
- Added some screws to hold the drawer in place (this required gluing some scrap plastic inside the case for the screws to bite into)
- Boxed the final build up using a spare cardboard box (and some sheet card to hold the computer in place inside the box)