The Glass Server

"WHAT?!   -it's made of glass?"

-Oh yes, the glass server is made of glass.

Mr Cadbury's Parrot performs the ITX rap. (ogg-main.jpg)

More pictures:

Click here for a side view

Click here for an aerial view

Click here for a back view

Click here to see the glowing front panel, by day

Click here to see the glowing front panel, in the dark

Click here to see the boot screen image


Design Brief:

I decided early on that I wanted to use thick glass for the main case material. Glass doesn't attract dust or get scratched like plastic and can easily be joined together using clear silicone RTV sealant ( -check out the way people make glass fish tanks with this stuff).

Things I wanted from this server:-

Size:

It's not always easy to tell from a picture, but this server is 220mm high, 180mm wide, 155mm deep. You can add an extra 30mm to the width if you want to include the ATX power wires which stick out. I don't want to boast -much :), but I haven't seen anything this compact that can house 2 full size hard disks. Many of the small ITX cases cheat by using an external power supply.

In some of the photos, an IDE controller card is fitted. When I first tested the server, I used Windows 98 and found I could only address the first 120GB of the main hard disk. I bought a controller card to reach the full capacity. Since then, I've discovered that Linux ignores the motherboard's BIOS limitation and directly addresses the full disk capacity. Now I don't have the ugly IDE ribbon stretched across the front anymore.

Construction:

I measured the components I was going to use and sketched different layouts on paper. After considering aesthetics, ease of construction, wiring routes and thermal issues, I was left with one design.

I made a drawing of the three main panels and took them to a local glass company. The people there thought I was mad when I told them what I wanted the bits of glass for. -well they *did* ask :) I told them I wanted 6mm thick glass with the edges rounded and polished and told them where to drill the holes for the rope 'handle'. The cost was about 37 UKP if I remember right. I wanted dark smoke-effect glass, but changed my mind when I was told it would cost ten times as much. [gulp!]

As you can see from the photos, only three pieces of glass are needed, as the PSU at the top forms one of the sides. The case has open sides, which help cool the hard disks. In addition, the PSU draws air up between the disks, which helps a little bit. I stuck additional heatsinks to the biggest disk to help keep the temp low.

The decorated front panel is made of 4mm thick Perspex (an off-cut from work).   (Construction Photo)

The front panel is illuminated, and it is held in place with nylon spacers, which pick up some of the light and glow themselves. These have a 3mm thread sticking out at one end and can accept a 3mm thread on the other. I joined a few of these together to get the spacing right and used impact adhesive to stick them to the top of the parallel and serial port connectors, and to the side of the DIMM memory strip. This glue can be removed (with care) if needed and I used it because the silicone RTV didn't want to stick to the Nylon spacers. I took no chances the second time round and abraded the surface of the spacers with coarse emery paper and thoroughly degreased them too.

The space that the hard disks sit in is lined top and bottom with 25mm thick foam (another off-cut from work). The foam cushions the disks and avoids tolerance problems caused by the disks not being exactly the right size for their housing.

Motherboard:

The Via Epia VE5000 ITX format board came from http://linitx.com/ and cost 61 UKP. The motherboard is bonded to the glass with spots of clear RTV silicone sealant. If the motherboard needs replacing, it could be done but it wouldn't be as easy as removing one that is screwed in.

The LCD:

The backlit 40x2 LCD display came from http://www.milinst.com/ (expensive but looks good). This one is controlled by parallel data signals, but a more expensive serial version is available. It wasn't easy to get this display working because I had to piece together the information I needed from several websites, data sheets and my own experimentation. I would have liked to find a website which shows what happens at each stage of the control process ie. send *this* command in the program, the voltage on the parallel port pin changes to *this* value and the LCD will do *this*... The datasheet for the display contains an assembly code example for a Z80 microprocessor(!), another website had an example program for Linux, written in C, which helped a bit but referred to control pins on the parallel port that weren't being used in the wiring diagram I was using. Anyway, I'm sure you see what I'm getting at.

Click here to get the QBASIC v1.1 Test Program for the LCD

It is possible to connect these displays using just two fixed value resistors, most websites show complex arrangements using variable resistors and capacitors everywhere. If you want more details of how I connected this to the parallel port then let me know (see the about page for my email address).

ATX Power Supply:

The power supply came from http://linitx.com/ and cost 35.5 UKP. Although it has a temp sensitive fan, it revved up to full speed within 5 seconds of switching on, even under light load. I *had* to make some mods... I added a 1k resistor to the temp sensor inside the PSU and moved it further from the heat source. Now the fan revs up when under load, but slows down again when the server is not in use and the hard disks spin down.

Wiring:

I kept this minimal and used just a small momentary switch connected to the power pins on the motherboard. The switch is discreetly glued to the top of the motherboard. I used very thin 'Kynar' wire to connect the LCD and LEDs in the front panel. This stuff is a pain to strip the insulation off, but looks very neat when it's done and it is easy to solder as it is silver plated and the insulation doesn't shrink.

I shortened the 80 way IDE ribbon cable to tidy things up. This is not easy, and even getting the connectors apart without breaking them is a challenge. (It used to be so much easier to shorten 40 way cables...) The result looks neat though.

Decorative Front Panel:

I first saw this illumination technique on a website called http://metku.net/. Basically, you drill holes in the edge of a Perspex panel to take some LEDs and then polish the other edges. The light gets reflected internally and makes the edges glow. Also, any scratched-in designs get lit up too (the scratches do not need to be deep).

The LEDs need to be high brightness for this to work [use 1 cd (candela) or brighter] -ordinary LEDs won't do.

I used a wooden block, wrapped with wet & dry emery paper to polish the panel edges in three stages: 400grit, 800grit, 1200grit, with lots of water and a little added detergent to stop the paper clogging. Finally, I used Autosol metal polish to make the edges really shine. I resisted the temptation to remove the protective film from the Perspex until last to avoid getting unwanted scratches on the surface, -that's harder than you can imagine [grin].

For the design, I made a mirror image of the Tux figure and stuck it to the front of the panel. Next I got a friend, (better at art than me) to scratch in the design, with a compass needle. The image shows Tux with a fly-swatter in hand (flipper?), about to stamp on an MSN butterfly he has caught. -A bit harsh perhaps, but it's made a few people laugh.

The 'Handle':

The handle is made from 4mm braided cord from a rock climbing shop. I don't imagine for one minute that people use anything this thin for climbing with, nevertheless, it's colourful, cheap and just what I needed to finish off my project.

Still to Come:

LCD wiring diagram.

home   (http://www.plees.f2s.com/ec/index.htm)
Last Updated :   29th December, 2004 micro logo