Coca-Cola Minifridge PC Build Log

tommoose13 · March 17

The build is complete! Here I will post the story of building this labour of love, and cover some of the pitfalls I ran into and creative details of keeping as much of the original minifridge features as I could. If you're after only the final build, look no further than this post! If you'd like the full story, read on as I build up this thread.

tommoose13 · March 17

The first step was gutting the old minifridge, taking out the pop can shelves and non-functional cooling system.

tommoose13 · March 17

tommoose13 · March 17

Next, I grabbed a mining rig frame from aliexpress and after trimming off the PSU mount, I cut out the left side of the fridge with a dremel for the rear IO. Here we ran into old spray foam insulation that we'd be dealing with a lot in this project, gloves and respirator came in handy here!

tommoose13 · March 17

I had the idea of re-using the case buttons for a power button and made a post on the forum asking about power button mounts. This is where designing and 3D printing started in this project. I picked up a set of digital calipers on Amazon and downloaded Fusion360 for personal use, and I designed a simple structure that would allow me to mount a computer power button behind the old "vend" buttons. Our local library offers affordable 3D printing services, so I began making a relationship with the folks that run the program there. At this point in the project, I thought I'd have one of the six buttons for power and that would be it... More on that later!

tommoose13 · March 17

I figured I could house the power supply in the back portion of the case, since I wanted to keep the power cable in the same spot, and have a passthrough hole for power cables. I measured out the diameter necessary to slip a 24-pin cable through and 3D printed a grommet, since the hole would pass through the nasty insulation layer. I determined an SFX PSU would just nearly fit in the back side, and made a cutout to allow the case to close without bulging. I also acquired a 90mm hole saw, and drilled a hole for the 92mm fan to intake on the back side. Standard mounting wasn't an option here, so I hijacked the M3 screws that kept the fan/cover on the psu, got some longer screws and mounted it sideways to the back panel. I screwed up a measurement for the power cable extension, so I ended up with an extra-tall cutout and four screw holes instead of two... whoops!

tommoose13 · March 17

I was planning to have countersunk bolts run through to the back side of the case to hold the motherboard tray in place, and noticed the frame warping from the clamping pressure. To combat this, I found some thick washers leftover from a TV wall-mount and superglued them to where I would be mounting the frame to the case. I ended up gluing metal washers to the thick ones to make the fit just right.

tommoose13 · March 18

The next plan was for two 120mm exhaust fans on top, so I acquired a 120mm hole saw and, after much double-checking my measurements, drilled straight down through the top. Plenty of insulation here. I designed a part that would be square on the bottom to house the fans, and cylindrical up through the top to save on material costs. Getting these printed proved a bit difficult, the white filament we had been using was warping, so we ended up printing in red and it came out perfectly. Originally I had a full square of material around the fans in my design, but I realized I could do a three-walled design to make it more seamless.

tommoose13 · March 18

Next, I designed a fan grille with the Coca-Cola logo to match the build. I based my design on a thermaltake 120mm fan grille I had laying around and... I do not recommend what I did. I offset the grille from the base of the frame, and the supports were INCREDIBLY DIFFICULT to remove. I spent a few solid hours filing away the remains, and it didn't turn out perfect in the end. It was functional enough to do the job though. Lesson learned, if I ever design another fan grille that I intend to 3D print, I will have the grille flush with the base.

tommoose13 · March 18

This is the part in the build where I was struck by inspiration. Before this, I knew I wanted to put some RGB strips in the case to give it looks, but I had thought I would get a motherboard that supported RGB strips and control them through software. I remembered that the fans I got for the build came with a three-button controller. If I could get another three button controller for the RGB strips, I could repurpose the old vending buttons as RGB control buttons!

Sure enough, amazon had what I was looking for - a SATA-powered 5v ARGB controller with three buttons! I opened both up and using a paperclip, I shorted the contacts on the switches to figure out what I would need to solder onto for the buttons and made an amazing discovery - both controllers were a "contact-to-ground" switch setup. This meant instead of 6 contacts per board I'd only need 4. You know what else runs on 4 wires? USB! I picked up a 9pin USB front panel extension cable and routed it through the side, giving myself a quick disconnect should I ever need to upgrade this system in the future.

Being used to soldering larger potentiometers in guitars, I knew enough to get the job done, but it definitely wasn't pretty. I gorilla-taped the cables to the case and covered everything in an excessive amount of kapton tape to ensure nothing would get damaged once more cables got stuffed in the back. I then printed off more power button adapters (white filament was giving us trouble again, so we went with black this time), got my hands on some 4-pin dupont housings and a dupont crimper, and set up the lights!

I have to add, dupont pins are a PITA to crimp. I did about eight test crimps before I got comfortable with the results, and still had to re-do two of the "no pressure, don't fail" ones. Ethernet I got good at much quicker, so props to anyone who is actually good at hand-making these things.

tommoose13 · March 18

With all of that out of the way, I had only intake to think about, so I went ahead with designing a 140mm fan interface. I chose to go full square both to not order yet another hole saw, and since the thickness on the side was less of an issue than with the top. Here's where I remembered... I really don't have the steadiest hands. I ended up with some nasty gaps on the inside, so I ended up needing to plan for finishing plates. ETA: It really didn't help that the inside was slanted... More on that later!

Having a poor experience with my previous attempt at making a fan grille, and eager to support a local small business, I found a fellow Canadian offering custom fan grilles on etsy, and sent them a message. Ethan at WestCoastCreated worked with me to get the design just right and I was really happy with how they turned out!

In my quest for RGB I hunted down some cooler master RGB fans (12v RGB, trying to keep all the fans on the same controller) and I was really disappointed in them. The airflow ratings on the spec sheets were barely over half of a noctua... So that's what I got instead!

tommoose13 · March 18

At this point I'm trying to source cheap PC parts since most of the budget sank into the case, and I found a Ryzen 3300x and Gigabyte B450 motherboard combo for $150. Score - that'll definitely run rocket league and not cook itself in here!

I watch builder stuff on youtube while scrolling the used marketplaces, and I forget where I saw it, but I stumbled across "caulk saver" tubes. I thought "this would be perfect to ensure I don't get any of that nasty insulation falling into places I don't want it to!" Sure enough, my small-town hardware store stocks the stuff, it's really cheap, and it did exactly what I needed!

tommoose13 · March 18

I wish I had taken some photos of the prints before I installed them, but the 140mm finishing plates I mentioned were goofy in three dimensions. These are the best angles I can get of both the bottom and top plate models to show how goofy they are, but measuring these nearly broke my brain. Since I was doing the side, I figured I would do the top too. Thankfully the top was both symmetrical, and flat.

The final piece I added would be another finishing plate set, for the top of the case. The grilles I printed were about 1mm too small to perfectly cover the duct holes, and I REALLY didn't want to re-print them larger, so I created a nice beveled plate set to support them and cover the holes properly. This solved two problems for me:

1 - Somehow the top 120mm fans ended up slightly rotated in the mounting, and the screw holes on the top did not line up correctly. Luckily the fans friction-mount in place (I will cry if/when either of the fans there fail as I will probably rip off the finishing plates getting them out) so I didn't need to run bolts all the way through.

2 - Finding M4 or smaller screws/bolts at 90mm length is nearly impossible, probably for structural reasons. The one set I did find sheared the packaging in the mail, and all I received was an empty, damaged envelope.

tommoose13 · March 18

If you've made it this far, thanks for reading! If you're inspired to build something, and are willing to invest in the time, tools, and skills you need for the job, you can build anything. Here's some more pics of the final build!