I have been toying with the idea of making a major Mac mod for awhile now. The book of CD's in my car is starting to look like the Library of Congress, so a carputer would be a huge convenience. At the same time, having ripped my entire CD collection to MP3, I have come to realize that in order to make the most use of the music I'll need a dedicated music playing/streaming computer for my apartment.

The decision was made for me when I got a beige G3 desktop Mac on the cheap...

The beige G3 case: closed, without the case-top and open

The fact that MacMod.com was running a modding contest also played a small role in the timing. :-)

The motherboard was too big for any of the car-mods that I had planned and innovative new designs such as the Bait Box Mac were just too awkward. The carputer would have to wait for another day.

The Bait Box Concept

The beige G3 is unique in that, having been designed during the brief period when Apple licensed clones, its Gossamer motherboard is roughly the same size as an ATX board and it can use a PC ATX power supply if you move a jumper next to the PCI slots.

The jumper is near the reset button behind the PCI Slots

I spent some time shopping for a PC case to mod, but it didn't work out. Only MicroATX cases are small enough to fit nicely in an entertainment center and that's the wrong form-factor for this motherboard.

It was obvious at that point -- I had to make a case from scratch.

This computer was supposed to be hooked up to my stereo and television. It had to be a fairly small case and I was willing to lose the CD ROM, Zip and Floppy drives. I experimented with paper cutouts and came up with a 7.5"x13"x13" minitower.

Test fitting paper walls and components

Only the use of a MicroATX power supply and an elevated drive-mount let me squeeze all of the guts into this space. The fan on the PSU doubles as the case fan (I substituted a clear fan with a red LED for the black one that came with the unit). Because the case was crowded, I decided to add a fan to the heatsink on the CPU as well. Note the ground on the heatsink -- it helps protect the CPU from EMF.

New CPU fan (note the blue ground wire) and PSU with 1/8" clear acrylic sides

I experimented with several materials before settling on .25" acrylic sheets. Acrylic is fairly easy to work with and is very scratch resistant. The latest craze in case mods is to use clear lexan, which is practically bulletproof, but lexan has to be cut by a professional and that can be very expensive.

I bought two large sheets of acrylic window material from Home Depot. After some experimenting, I found that the trick to cutting acrylic is that you don't cut it at all. I used the back edge of a #24 X-Acto knife to create a small groove and then snapped the plastic along that stress-point. The edges were not all perfectly flat, but I used clear epoxy to fill in the gaps when the sides were fitted and a bead of non-conductive silicone adhesive for extra support on the inside.

You need corner clamps. This is from the assembly on my dining table!!

Blue paper tape was used liberally to keep the protective plastic wrapper from peeling off prematurely.

Cutting holes for the ports and PCI cards was the most difficult part of the project. Smaller holes were made by drilling and filing. Big cutouts were made by drilling successively larger holes at each corner, starting with a 1/16" bit, then a 3/16" bit and finally using a unibit to make a hole approximately 1/2" across. At that point, I was able to use a jig saw and coping saw to cut away a rough box-shape. I finished each hole with a flat metal-file and needle-files. Filing the acrylic took several hours and was incredibly noisy.

Rough holes for the ports and PCI cards.

I love my unibit! You can't just drill acrylic with a regular large drill bit unless you like splinters and cracks. Once a hole is big enough for the unibit, though, it's a piece of cake. Because the unibit is tapered, you have to drill into both sides for a clean hole.

My unibit

I ordered the clear door hinges and PCI slot-cover screws from U.S. Plastic. I couldn't find an adhesive that would take the shearing stress so I used flat-headed case fan screws to secure the hinges. I also used case fan screws to secure the drive-mount. The screws self-tapped in the acrylic. PCI slot covers (not pictured) were made from 1/8" acrylic scraps.

Case fan screws

Test fitting the box on my entertainment center

I finished the case with black wire-sleeves, a black round IDE cable and an illuminated anti-vandal switch for the power button. A CPU thermometer is mounted to the front-inside of the case with removable 3M clear adhesive squares. I blocked out the area around the PCI slots with shiny white pasteboard to reflect more light inward.

Test Fitting the components on my desk

The G3 is connected to my television using a GrandTec composite video cable that is powered off of the USB port of a USB/FireWire card. It is connected to a USB mouse and foldable keyboard that stow away when not in use. It serves music via iTunes/Rendezvous and ShoutCast. I use SSH and ARD to control it from my laptop. Two future purchases are the Keyspan Digital Media Remote (which uses IR and is therefore compatible with my television's programmable remote control) and a wireless 3D mouse and keyboard.

Time to complete: 2 weeks.
Difficulty: Power Tools Required.
Expenses: < $120 for raw materials OR
Add'l Expenses: Up to $200 if you need to buy the tools.