By Nick Pelis - 07 July 2002
With more and more people buying computer cases with windows, cold cathodes, bay buses, even custom paint jobs, the truly hardcore case modders are quickly finding themselves having to search harder and harder for an original case mod. Everyone has done black cases with blue lights. Everyone has installed case windows, cut blowholes, and maybe even installed a baybus. The modding community needs fresh, new ideas, and I believe I may have one.
This idea came me one day when I realized 1) I drink a lot of coffee and 2) I spend a lot of time at the computer. I'd already gone through several coffee pots when it suddenly struck me: why not integrate a coffee maker into a computer case and get the best of both worlds? Thus began the search for The Caffeine Machine.
First, it's necessary to take a look at how coffee makers work. They are extraordinarily simple devices, with three major components:
Water is poured in through an opening and temporarily held in a tank.
The tank is connected to a heating element via a one-way valve.
When the heating element is turned on, the water boils and expands. The one-way valve prevents it from going back into the tank, so the only place for the heated water to go is out, where it falls into the filter and makes coffee.
The next part involved a lot of brainstorming and trying to come up with a setup that would work. Here's some preliminary sketches I did:
The next part of the design phase involved selecting the case and the coffee maker. I was a little concerned about space requirements, as fitting both the coffee maker and the actual computer components together would require a bit of shoehorning. Ultimately I settled on the InWin Q500 case due to its full tower size, simplicity, high-quality steel construction, and low cost. A picture from the manufacturer's website:
As for the coffee maker I settled on a $15 White-Westinghouse 4-cup coffee maker from the local K-Mart. Unfortunately there wasn't enough room available in the Q500 for a larger-capacity version. Another factor was that the manufacturer used normal, Philips screws, whereas the bottom of most other coffee makers have funky screws, clearly designed to keep people from tinkering with them (this is from my Mr. Coffee pot):
After completing some initial measurements, I decided to build an enclosure for the coffee maker portion out of sheet metal, which I felt would be easy to work with but sturdy enough for my purposes. Looking around town, I was able to get a 3' x 3' sheet from the local sheet metal store for about $14. The next stage involved sketching out how the pieces were going to be cut and how they would fit together:
Note to anyone attempting this or any other significant mod: I cannot stress enough the importance of figuring things out on paper before starting. I actually had to redo the coffee maker enclosure twice because I didn't measure it correctly or because one of the pieces didn't fit correctly. The old adage of "measure twice, cut once" certainly applies here, so make sure you know what you're doing before you pick up that Dremel! With that in mind, I drew up the diagrams I used to make the enclosure, taking into consideration how all the pieces would fit together:
With some solid measurements, the next step involved sanding down the Q500 to the metal and then removing a significant chunk from the front of the case. For sanding purposes, I used a sanding disc with 80 grit sandpaper (I'm impatient), steel brushes for the Dremel, and hand sanded only when absolutely necessary. This took only about ten hours or so to complete. Cuts were made using the reinforced cutting wheels for the Dremel (note the missing portion):
I then cut the enclosure pieces using reinforced cutting wheels for the Dremel to have greater control over the small corners and tiny cuts that had to be made. I then formed the pieces by taking the cut piece of sheet metal, putting it in a vice grips, and then using a hammer to bend the metal. Finally, the pieces were attached by means of a pop riveter. I decided at this point that I was going to install a hot plate on the top of the case as well--more on that in a bit.
With the enclosure built, I focused my attention on the next significant part of the coffee maker: the water tank. This was by far the most difficult part of the entire project as it had to be built to exact specifications, from scratch, and then leak-proofed. Originally, the idea was to build a cube-shaped tank and put it in the top of the case where there was plenty of room available. I bought a sheet of acrylic at the local hardware store and built a test tank:
This was when I discovered The Problem. In order for the coffee maker to work as shown above in the diagram, the water needs to travel up the tube to the coffee filter basket only when it's hot. By placing the bottom of the water tank above the hot water spout, I realized that a siphon would pull water through the system as soon as the tank was filled--not a good thing! This required a redesign of the water tank, so I settled for a book-shaped tank, to be placed directly behind the back plate for the coffee maker enclosure:
Another problem encountered was waterproofing the tank. After trying various epoxies and cement with wildly varying results, I simply could not completely leak-proof the container. I ended up actually making my own acrylic cement which welded the pieces together to create a leak-proof container. After drilling holes for the hose connections, I set the coffee maker portion aside for a while to work on the rest of the case.
I've always been a fan of case windows, and thought that people should be able to see inside the case as the water flows around, so I bought a piece of Lexan at the nearest Home Depot, cut it using a jigsaw, and engraved a coffee mug motif using the engraving bit for the Dremel:
This also gave me a chance to work on the electrical system for the coffee maker. I wanted to keep things as simple as possible, so I decided to leave the electrical systems for both the coffee maker and the hot plate at their default 110VAC circuits. I cannibalized a nearby dead power supply for parts, and decided at that time to also use the same power connector for the coffee maker as is used for the computer power supply. For safety's sake, I fused the circuits and then drilled the holes for the fuses on the back of the case:
At the same time, I wanted to have a little fun with the case, so I visited the nearest RadioShack and built a +12VDC power distribution block for lights I planned to place inside. I made sure to include fuses for overload protection and install protection diodes to prevent any power fluctuations from going back into the computer's power supply:
I also decided to integrate a remote-control relay board and a stereo VU meter into the case as well (call it frosting on the cake). These are really simple circuits to build, so instead of designing them from scratch I just bought the DIY kits (electronickits.com, p/n CK1609 & CK1005). These were then assembled and mounted on a sfeces piece of sheet metal:
I spent quite a few hours deciding how to light the interior. I wanted a white kitchen appliance paint job with a red lighting effect, so I looked at different lighting products. Unfortunately, standard red cold cathodes were too pinkish and too long for what I needed, while red neons weren't bright enough. Both were extremely expensive, so I ended up making my own lighting, using 660nm super-bright red LEDs:
Finally, I had to decide how to wire the coffee maker & hot plate. Using 110VAC as a power source, I kept as much as possible in the original circuit as I could and drew up this wiring diagram:
At the same time I also had to redesign the front bezel, as cutting it out to make room for the coffee maker removed the section with the indicator lights. I drew up a diagram and then made the changes using a drill and a Dremel:
The next stage was to paint the case, which took the longest to do. I started by applying three coats of Rustoleum clean metal primer, sanding it down in between the coats. That was followed up with five coats of Rustoleum white gloss kitchen appliance paint, and topped off with three coats of Krylon clear coat. Sanding took the longest time, but was well worth it. Plastic pieces were lightly sanded and then painted with three coats of Dupli-Color white gloss vinyl dye. This part took approximately three weeks to complete, but I was glad I spent the time and the attention to detail that I did:
Now came the time to start putting all of the elements back together, starting with the coffee maker enclosure. After replacing the connectors on the heater with quick disconnects, I smeared the heating element with silicone heat transfer paste and screwed it to the bottom of the enclosure. Note the clips on the enclosure for the water tank:
Next came assembling the enclosure, case, and modified front bezel together. I decided to mechanically attach the coffee maker enclosure to the case via four removable screws (in case I have to take it apart later):
At this point I also tested the electrical systems, including the coffee maker hot plate, auxiliary hot plate, relay control board, stereo VU meter, and +12VDC distribution block. One interesting discovery was that while the auxiliary hot plate with a resistive heating pad only drew 0.250 amps of power, the coiled resistor for the coffee maker hot plate drew an astounding 5.3 amps! I then used this information to select the appropriate fuses for circuit protection.
Almost there! Next, I had to attach the window to the side panel. After using a stencil to paint the phrase "Caffeine Machine" on the side, I drilled out holes in the side of the window and used pop rivets to attach it to the panel.
Finally, after months and months of engineering, cutting, and drilling, I was able to begin putting everything together...
...to assemble--The Caffeine Machine!
Final hardware configuration:
Abit VP6 motherboard with dual 1.0GHz Pentium 3 processors
1 GB of PC133 SDRAM
1x20GB Maxtor boot drive plus 2x40GB Maxtor storage drives in RAID 1, all hot-swappable
CD-ROM, Sound, & Network
Most frequently asked questions:
Q: Aren't you concerned about condensation from the coffee maker?
A: Not really. I reversed the fans inside those mobile hard drive cages to blow air away from the case. Some water does condense on the outside, but everything is sealed up pretty well.
Q: Aren't you concerned about the electricity demands of the coffee maker?
A: Yes and no. It concerns me that it take five times as much electricity to run a coffee maker than it does to run a high-powered workstation. On the other hand, if the coffee subsystem shorts out, I can replace the fuse much easier than I can replace my burned down house.
Q: Doesn't it get hot inside the case?
A: Absolutely not. Both CPUs run at about 30°C, irregardless of whether or not the coffee maker is turned on. I attribute this to the cooling scheme; two 120mm fans pull air from the bottom of the case to the top, and keep everything cool.
Q: Doesn't the coffee taste nasty?
A: The first couple of batches were gritty, from the dirt and sawdust that got into the system. Nowadays, I depend on The Caffeine Machine to wake me up in the morning.
Q: Why did you use a remote controlled relay kit instead of a timer-based system?
A: A timer-based coffee machine is just as easy to do (i.e. "turn on automatically at 6:00am every weekday). Unfortunately, I would never remember to fill the water tank and change the coffee grounds every night and would probably wind up using the same coffee for about a month! (eeeewwwww). Instead I wake up in the morning, hit the button on the remote, and have plenty of coffee by the time I get out of the shower.
Q: What's next?
A: I'm thinking of developing The Caffiene Machine v2.0. Expect to find espresso, aluminum construction, and other sources of caffeine besides coffee (think: Mountain Dew dispenser/crushed NoDoz InstaCrack).