Emmet's Hedgehog - HTPC

[turkster]

There's been a load of interest in HTPC/Media Centre PCs around hexus recently - what with reviews, mods and discussion etc - so I might as well add my attempt to the mix .


Me and my brother have been contemplating building a HTPC for a few months but being a bit strapped for cash and with no suitable hardware to hand we couldnt really do much. Then a few weeks ago I was given a rather dodgy 1.2ghz AMD system with 256MB ram 40GB hdd Radeon 7000 with tv out etc which seemed to fit the bill. Problem was it was a bit dodgy with intermittent optical drive problems and various other dubious problems . Anyway by paring it down to one optical drive, 1 HDD, and installing Windows XP we got it working fairly well at least for playing dvds mp3s, oggs etc.


Our idea is to have the HTPC fit in our HIFI rack but the system was in the standard dirty beige tower case . Not wanting buy a case or to build one from scratch we decided it would be possible to cut down the atx case lay it on its side and just about fit it in our HIFI rack. On the rack the front of the case is the most important and visible part while the sides and top are not really seen much . So we came up with this as the design for the front;



Most of it will be brushed aluminium with a line of polished copper across and splitting over the drive bay. The switch will be a solid aluminium lump fitted in the line of copper.

[turkster]

Seemingly, midi tower cases (when laid on their side) seem to be almost exactly the same width as standard seperate Hifi components which is kind of handy for our purpose. So all we really needed to do was cut a section off of the top (when laid on its side) of the case to make it thin enough to fit in our rack. Luckily our Hifi rack has fairly large spaces between the shelves (to fit chunky NAD amps ) but even so we had to cut about 2 and half inches off the case to enable the case to fit into the rack when laid flat. This does, just, give room for pci/agp cards withought any restriction and enabled us to retain the pci/agp shield area on the back of the case.

Although not really necessary we decided at this stage to shorten the case from front to back by taking a section off the front. While this does make the whole thing more compact it also makes it weaker.

Anyway here's a pic of the cut down case



The new psu mounting position can be seen on the side of the case. That was the only position it would fit without major redesign of the motherboard mounting position. It does mean that the power cable will be plugged into the side of the case which is not a very elegant solution but it hopefully wont be too noticable. All the cutting was done with a 4inch angle grinder with a nice 1mm stainless blade. Although fairly quick and painless way of cutting sheet metal it is fairly tricky to get a dead straight line with it. I also bent a flange down around the cut edge by scoring the metal with the angle grinder and then bending with a large pliers.

[turkster]

I know the work so far on the case is a bit rough (it looks worse than it is) but we had made a decision not to bother getting the backend perfect. Once sprayed black and in our HiFi rack we reckon it wont be too noticable. That way we can spend more time on perfecting the front and getting it so good no one will notice the back .

Here's a pic of the cut down case with the Psu and mobo mounted in place.



The psu is only 250 watt but it is very very quiet which is nice considering it's an old PSU. The CPU fan, on the other hand, is a bit of a screamer so the heatsink has been taken off so we can fit it to a larger and slower revving fan.

The hdd will be mounted in the corner at the back where the PSU originally went. There is potential room for a couple of hardrives which is handy. 40GB isnt going to get us far if we use it as a PVR.

[turkster]

Here's the hardrive mounted.


It is screwed directly to the side of the case with rubber grommets to (hopefully) absorb some of the vibration. Its a fairly slow 5400rpm maxtor and probably the most noisy thing in the system . Still its easy to upgrade. A 160GB Samsung Spinpoint would be nice .
You can see the old 60mm CPU fan at the bottom of the pic.


Here a pic of the case with the top fitted on.


It doesnt look as bad as we expected . The whole thing is going to be sprayed matt black which should hide the imperfections.

[turkster]

After some thought we decided to attach the aluminium and copper of the facia to a wood bulkhead. This will give strength to the facia and make it easy to mount the optical drive and switches LEDs etc. The other option would have been to use sheet steel (like the rest of the case) but this does not have the same rigidity as the wood and seeing as we have already weakened the case by cutting it down a strong front is necessary.

Pic of the bulkhead squared up, cut for drive mounting point and sprayed black.


MDF would probably have been the best material for this but we didnt have any to hand so we knocked it up out of an old 1/4 inch pitch pine door panel. The hole to the left of the 5.25 inch drive slot will hold the eject switch for the drive. This will be behind the left most point of the drive door (see diagramn at top) so pressing the left side of the drive door will eject the drive tray.

To do that the optical drive had to have it's switch remote wired;


The drive is a standard 16x DVD rom, nothing fancy I'm afraid . The Drive activity LED is also wired up here. The two switches on the drive were unsoldered and will be used as power on switch and drive eject. They are both nice short action switches, handy for this job.

[daniel_owen_uk]

HTPC on the cheap, I like it, will be keeping an eye on this one m8, good luck.

[turkster]

Cheap's good, if it works .

Tbh I'm really gonna have to get a tv tuner card and larger hardisk to get it working make it into a fully featured HTPC but I havent yet decided what software to run on it. I'll be interested to see how Directhex gets on with Mythtv or Freevo in his project .

[turkster]

I cut out the 1.2mm aluminuim sheet for the facia;


I cut it from a large sheet with the angle grinder and 1mm wheel. Its a tricky job cutting that kind of thing if you dont happen have a large guillotine or laser cutter . You cant use a hacksaw or piercing saw because it doesnt have the throat and snips would bend the sheet too much. Anyway the angle grinder does the job although the sheet needed a bit of cleaning up with a file afterwards. I then rubbed down one side with wet a dry to be sure that I could get a good finish on it, ie make sure there was no deep scratches etc. Then I covered it with masking tape to protect it from damage during the rest of the work.

I drew up the design for the front in AutoCad with all the drive openings and switch positions marked and then it was a simple job to print out full size on two A4 sheets. I can stick the printouts to the aluminium sheet (masking tape side) with superglue and I can follow that when cutting.

Our design also requires a copper sheet behind the aluminium so that when the aluminium is cut and stuck in front you will see a 6mm line of copper going across the facia and around the drive door.

Here's the copper sheet partly cut out laying on the wooden bulkhead roughly in the correct position;


The slot cut in it is just big enough for the drive tray to eject through. It still needs holes for drive activity lights, eject switch, and power switch to be cut.

As always these things take longer than you expect .

[Norky]

Facia design looks great, keep us posted

[turkster]

Facia design looks great, keep us posted

Thanks Should hopefully look pretty nice when finished.

[turkster]

Here's the main power button
#

It was cut from 6mm alu bar stock and then filed and lapped. The notch will be the hinge point which will be hidden behind the facia. I only wanted a small minimalist pinprick of light for the power button so the light collecting rod is only 2mm at the front of the switch. I drilled the hole 2mm right through the button and then 5mm from the back and turned the end of the light collecting rod down to 2mm. It was actually quite tricky to get the rod that small without melting it but anyway it looks pretty nice now.

We were also messing around a bit with LEDs


We had originally thought that we wanted the main button light to glow purple (red and blue LED combined) when off (but plugged in and psu turned on) and then turn a brighter blue when powered up hence the configuration of LEDs in the pic. After a lot of fiddling with the LEDs, resistors, etc and fiddling with the positioning of the three LEDs we decided it would be simpler if the button light was purple when on and blue when on standby. That way we only need two LEDs and it is lot easier to position them nicely so we get a gently blue glow on standby and a good purple when powered up .

[turkster]

I spent a few minutes fixing an old 90mm fan over the cpu heatsink;


I couldnt be bothered spending too long on it so I just bent a few bits of copper wire which act as spacers and hold the fan a few cm above the heatsink. When run on the 5v rail it is nice and quiet and produces a good flow of air over the whole mobo. I checked the CPU temps and it stays nice and steady at around 35 deg c even when overclocked to 1.4ghz

Here's the aluminium sheet roughly cut out;


You can see the printout stuck on the front. I cut most of it with the hacksaw and finished the curves with the piercing saw. Thats the easy bit though. Now it has to be cleaned up with a file and finished so that all the lines are parallel and the curves are correct .

[muddyfox470]

looking good so far

thats sum task you have undertaken.

i can't really comment much on what i see, until its finished, but its coming together!

[Norky]

Cleanly cut, nice one

[turkster]

Well Ive got some more done but some mistakes as well .

Here's a pic of the switch mounted through the copper sheet;



I cut all the holes in the copper and sanded it down to a nice finish and then lacquered it but as you can see in the photo I got losts of dust on it when it was dryng so it will have to be done again .


When we originally cut down the case we saved the 5.25 inch drive cage and after a bit of hacking with the angle grinder it is perfect for screwing to the bulkhead and mounting the DVD drive.



The drive slides on on its quick release rails and fits in perfectly. The little screw at the corner of the drive is to hold the drive eject switch firmly in place.

[turkster]

Here's the other side of the drive cage;



The wires are for the drive activity LEDs, hard disk on left and optical on right. The LEDs are 3mm bright blue jobs salvaged from an old Akasa fan. They are going to shine through 1mm holes in the copper sheet although even so they are going to be fairly bright - possibly too bright for a HTPC.

I just found that, when fitted to the front, the optical drive only barely clears the RAM stick by 1mm or so .