This time I wanted to share the thoughts and ideas I've been having around building a case to hold my computer when it's eventually complete. I wanted to use a material that would be easy to handle and work with but also one that would produce a nice looking result. I was initially drawn to using wood or possibly even laser cut plywood but in the end I settled on aluminium profile as its sturdy, easy to assemble and, I think, looks really great. In addition to this it's available in a large variety of sizes, shapes and there's plenty of fixtures and fittings available for it.
If you haven't come across it before, aluminium profile is basically created by extruding aluminium through a die to produce bars of varying lengths. The clever thing is that the dies are shaped so that channels are produced that can fit bolts or screws to allow profile to be joined together or for fittings to be attached. Also, the cross section is designed to have maximum strength but minimal weight therefore a given length of profile is very strong but very light. There's a quite a few different manufacturers of profile, each with different cross section designs, but I've gone for the Bosch Rexforth range as I found they had the best selection of connectors and fittings.
One of the key things with aluminium profile is to choose a series (often determined by the width of the profile cross section or sometimes by the slot size) and then stick to it. This is because all the parts in a series are designed to work perfectly with each other but not necessarily with parts from other series. As the total weight of my computer won't be all that great I've gone for the lightest smallest series which is based on a cross section of 20x20mm with a 6mm slot. A cross section of the 20 profile along with a 20R profile which has a rounded edge looks like this:
By the time the computer is finished there'll be four backplane cards which can each carry up to five cards. Based on this the basic frame of the enclosure looks like this: