Posted on July 2, 2004
I have long been in awe of the beautiful and creative designs that people have created for the mini-itx form factor. Unfortunately I am a destructive force when paired with a tablesaw or dremel drill. So I searched around for projects that wouldn't require powertools and come up with the Mini-Mesh Box, which required nothing more destructive than a pair of wire cutters and a bottle of glue.
The resulting system is cool and quiet (no problems with venting!), and is currently acting as a PVR for my TV room.
The main ingredient for my project was a mesh wire box with a hinged cover that I found at the local stationery store. It is designed to hold a ream of paper, and is roughly 9X12x2 inches in size.
Other parts that went into this project came from local computer, electronics, and hardware stores:
Nehemiah EPIA M 10000 motherboard
PW-80 80 watt PSU of the type that mounts directly on the board, plus the external 12V brick
256 Mb stick of PC2100 DDR RAM
A 20 Gb IBM Travelstar 2.5 inch hard disk, and a slimline DVD/CD-RW, both salvaged from a dead laptop.
3.5" to 2.5" IDE adaptors for the hard disk and DVD/CD-RW
1/4" hexagonal standoffs
Assorted LEDs and mounting retainer rings
Crimp-style connector housings and ribbon cable
Components for a serial port-based infrafred detector as described here
A quieter 40 mm fan to replace the one that comes with the M10000
A translucent vinyl report cover
Miscellaneous screws and washers
Mounting the Motherboard
An issue with the mesh box is that the bottom is flexible, allowing it to bow upward and short out the motherboard. To avoid this eventuality, I cut two 17x17 cm sheets of translucent vinyl from a plastic report cover. During the preparation of the mesh box I used one of these as a template for cutting holes for the mounting screws. Later the two plastic sheets became electrical insulators between the motherboard and the box.
Using the template as my guide, I snipped two small holes in the mesh box underneath the mounting holes in the motherboard. I then screwed the standoffs in from below. The image above shows how the standoffs mount.
Now came the most time-consuming part of the project, cutting the holes for the backpanel ports. I used the metal backplate provided by VIA to trace the port pattern onto another piece vinyl, and taped the vinyl to the mesh. Then I started work with my wire cutters.
About an hour later, surrounded on all sides by tiny sharp pieces of waste metal, I placed the motherboard into the box, and behold, it fit!
After mounting the board, I discovered that there remained just enough room to allow placing a PCI card using a riser board. However, when closed, the back rim of the mesh box would interfere with any ports protruding from the card. A few swift strokes of the hacksaw solved this problem without seeming to affect the structural integrity of the box or its lid.
If you look closely, you can see a small slot cut in the mesh just a bit to the left of the main opening for the PCI card. This slot accomodates the protruding lip of the PCI card's rear metal plate. The slot supports the lid nicely, preventing the card from wiggling around. The photograph below shows how the PCI slot looks when occupied by a CardBus bridge and a wireless card. I have since replaced the cardbus card with a PCI-based wireless card.