cassiopeia

Cassiopeia

October 2013

I’ve been thinking about building a smaller than usual (for me) general purpose PC for some time now, and through the year I’ve been getting together the parts that I will need. The first thing that blew me away was just how small these things are for their power.

Here are some pics to show you what I mean.

The power supply. This is a tiny 450 watt PSU that is fully modular yet is still rated at 80 gold. And it’s as light as a feather (almost).

The mini ITX motherboard. It’s the latest generation and has a quad core CPU. Here I’ve fitted a water block but I may make my own top for this later. The memory is low profile too.

This is the reservoir and pump in one. It’s so cute! This is plenty for cooling the CPU.

The graphics card is a mini version of the last generation nvidia GPU (this is a GTX 670). Still very powerful and can play almost anything (I think).

The radiator is for a 120mm fan and I was blown away with how well this was put together. Copper core, aluminium case bolted together and black chrome fittings. Wow!

So my thoughts originally involved laying all the hardware down flat and having the case open from the top. The internals were to be arranged to resemble an engine bay. Somewhere along the way the design changed to a vertical configuration, in the normal manner, with the hardware arranged into three ‘modules’, the PSU down the bottom, processors in the center and the radiator and pump/res up top. I also want the graphics card to be parallel with the motherboard (as with my last build, ‘once you go parallel you just cant go back’). Instead of mounting the graphics card in a permanent position however, I decided to set this area up so that the card can flip down so as to allow easy access to the motherboard beneath. The exterior is tending towards a wood and aluminium construction with (at this stage) a tripod type support (three legs). But these details will need to evolve as the project progresses. As usual I like to start at the heart of the system so work has begun with the processor assembly.

I need to get a look at what can be done with a flip up graphic card, so to that end some parts were made up and assembled to test various parameters. How high will the assembly be. How much space is required for the flipping action. What will it look like. How will this assembly fit with the rest of the chassis. By making a prototype I could answer all these concerns.

The parts consist of a dinky little mobo plate from 4mm alu. A GPU plate from 3mm. Some risers and locking support from 8mm and a extender cable tidy from 3mm.

These parts are made from alu sheet and plate in the usual way by cutting with a jigsaw or hacksaw and filing to final shape. A huge bonus is that all these parts are much smaller than I’m used to, so this work went quickly.

First the risers are fitted with two M3 screws each. These also serve to hold the hinging bar.

And below, the hinge bar is fitted. This is held in and allowed to articulate with two long M3 screws that have been trimmed down so they bottom out in the bar.

This is the support at the opposite side for the GPU plate. It has a drilling in the top to take a locking thumbscrew.

The GPU plate is fixed to the hinge bar.

And this is just a fancy cable tidy.

And we end up with a compact and light weight unit.

With the hardware installed. Initial thoughts; In this configuration only about 20mm is saved from the height as compared to the card being mounted in the PCI slot as normal. This is mainly due to the fittings on the CPU block. One obvious remedy (as seen on Cor Leonis) is to stagger the GPU. This will grant an extra 20mm height saving but will make the whole mobo/card unit considerably larger. I’ll have to think about it a while to see if that extra 20mm is worth it.

The cable tidy in action.

This is the lock made from an old cooler thumbscrew I dug out from my parts bin. The thread is M3.

Opened up you can see that there is complete access to the motherboard , parts and connectors. In this position it’s well balanced but I think that if I were to remove the CPU block, it will tip over.

Overall I’m quite pleased with this early result. Of course to make this unit as compact as possible, a water block could be fitted to the graphics card and the card position moved back, but adding liquid cooling means a bigger radiator, pump and res not to mention losing the flipping action because of the coolant lines. So this is not an option.

Back when I’ve played a bit more and have something to show.