Project: Homebuilt Smaller Form Factor

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widefault

Supreme [H]ardness
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Dec 18, 2000
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In order to avoid a cheap Dell at my job, I've been supplying my own work PC. Currently that's a power-sucking, heat-generating Pentium XE965 system in a classic Antec/Chenming Dragon case. It's more than adequate for my needs, but due to the layout of my office it sits on the floor and pretty much right up against my legs.

In the winter, it's nice, free heat! In the summer it is going to suck, so I've been planning on upgrading to a smaller form factor that can go on top of the desk.

I have some pretty basic requirements:
- Smaller size
- lower power
- quieter, although the current system is actually no louder than the Dell previously in my office
- a bit more stylish, not another cookie cutter system

I looked at Shuttles, the AOpen mini, and even the Mac Mini, but I just didn't care for them.

So that was part of my motivation, the other part was finding this. Originally I had planned on building another Radiation Meter PC, but with all the boards features I just couldn't squeeze everything in. Needed a better case idea, and it merged nicely with the other idea above.

I started out planning to bend my own case out of aluminum. Was shooting for something the size of a Mac Cube. I was having trouble finding good sheet aluminum, so that put me back on the drawing board. Then I remembered that I had an old aluminum breadbox stashed somewhere that I had once planned on turning into a PC case. Ooops, guess I never got around to that.

Finally fished it out and started measuring. It was "u"-shaped with the opening of the "U" facing the front. The bottom of the "u" would become the front, and I'd make a backplate out of the internal shelf it also had. Taller than I wanted at 8.75", but I'd be able to trim the width and depth to whatever I needed.

Long story short, here are the system specs and then some pics.

Commell LS-371
Intel Core 2 Duo T7200, 2.16GHz, 4MB cache
1GB Geil DDR2-667
Onboard Intel GMA950 video, good enough for Vista Aero
DVI, VGA, and Component video out
Onboard Realtek 5.1 sound
Onboard Intel Gigabit Ethernet
Atheros 802.11b/g wireless with external R-SMA jack
Seagate 7200.10 500GB SATA drive
Panasonic 8x DVD+/-RW Slot load slimline drive
generic zillion-n-1 flash card reader
100 watt power brick, board has onboard power circuit with 8-24 volt input
All to be cooled by a single Yate Loon 120mm fan

Front:
mermini01.jpg


DVD Side:
mermini02.jpg


Backplate:
mermini03.jpg


back of board:
mermini04.jpg


Bottom:
mermini05.jpg


Things left to do:
- make a new fan mount, screwed up while bending the old one
- figure out where the flash reader will fit and install
- Power switch and HD activity indicators installed
- sides for the case and figure out how to attach them
- slot for the DVD drive
- finish, uh, finishing the case surface. Needs to be cleaned up
- add cutout for parallel port, still needed for a printer

Right now I'm very happy with how it's going, even if a bit larger than I wanted. Around 9" tall, 6.75" wide, and 7" deep. Could have cut the width and depth a good inch, but I think I'd rather have the extra space for airflow. Plus it would have ended up a bit wobbly, which is still a problem until I get the fan bracket in place.
 
The sides will more than likely end up being mesh, need some way to let the hot air out of the case. I was originally going to have venting on the top. After some thinking, I knew i wouldn't be happy with how that would look.

One concern of mine is making sure the hot air can get out, but not get sucked back in through the fan. The fan will be parallel to the base, with about 1.5" clearance between the two. Should be enough distance that it won't be a problem.

And I have my dimensions figured out for the fan bracket/stiffener. Now I just need to cut it out, bend it to shape, and cut the hole for the fan itself. Then becomes the fun part of fiuring out how the hell I can fasten it in place. Trying to avoid too many fasteners on the front and top, but I don't have much choice. The other fun part is trying to hold the nut in place while screw it all together.
 
You could use magnets on the cover and case, so that the two would snap together. That way, you wouldn't have any externally-visible fasteners
 
Mohonri said:
You could use magnets on the cover and case, so that the two would snap together. That way, you wouldn't have any externally-visible fasteners
Click to expand...

Yeah, but find me magnets for aluminum. :D I'd have to use a steel mesh and then glue/epoxy the magnets to the aluminum main casing. Was something I considered, but I've yet to find plain steel mesh, only aluminum and stainless.

What I'll probably end up doing is drilling and tapping the side of the backplate. As for holding the edge of the side that would fit the curves, I have an idea for that.

Cut and bent my fan bracket last night, but apparently I screwed my measurements up by about 1/8" in each direction. It'll work, though. Just have to add a spacer on one end, case got a bit deformed when I got it installed. That spacer should also act as a vibration damper from the fan, so maybe it's not a bad thing? Ended up using 8 screws, 4 front and 4 in the back, two on each side. This leads to a second screw-up. While drilling the last screw hole, the bit wandered and the hole is off by a teeny bit. Helps that all 8 screws match the two on the top of the case, although I'd have loved no visible fasteners.

Tomorrow after work I'll cut the hole for than fan out of the bracket. Here's where I get to cheat. We deal with a lot of aluminum where I work, so I can use our shop for some of my work. My method hear is quick. Layout where I want the fan, then mark and drill where the screw holes should be. Using regular fan screws, I attach a gutted 120mm fan from an old Mac PSU. From here it gets real easy. With a snips, I'll usually cut out some of the aluminum from the center, leaving about 1/2"-3/4" on the inside of the opening I want cut. With the fan motor and blades removed, I can use the frame as a template. We have a router setup with a flush-cutting bit. The bearing rides on a flat spot in the gutted fan. Takes about 2 minutes and leaves a near perfect cut. I've even trimmed panels this way, beats the hell out of a dremel or tin snips.
 
Nice. How much did that board set you back, $600-700? What heatsink are you planning to use?
 
Around half that much, Commell isn't a rip-off like some of the other embedded board makers. Of course, add in a CPU and it can reach those levels. Good thing, it'll take a Yonah core Celeron-M or the new Celeron-M 520.[1] Not quite as "affordable" as the Commell LE-370 + Celeron/Pentium-M, but only around $50 more.

Commell includes heatsinks[2] with their boards[3], but I've switched to a larger one. This is what I've gotten with the 3.5" boards(Pentium-M and C2D), and this one is what I've swapped in for this setup. So far that combined with the 120mm fan is more than enough cooling. We'll see once I get it all together.

[1] If you can find one. Not only that, but pricewise it's not very far off from the C2D T5500 which is dual-core and a slightly faster clock-speed.

[2] I think this is only for the "non-standard" ones, the LGA-775 boards have standard mounts

[3]Another beef, not all embedded board manufacturers include proper heatsinks. Even fewer include all the cables for things like audio or DVI. Instead they expect you to buy them.
 
Got the power button and HD activity LED installed. Forgot the fan bracket at home this morning, so I won't get that finished until tomorrow. I'd take some pics, but the batteries in my camera died, so that'll have to wait.
 
Fan bracket is done, pretty much the whole layout is done. In the process of cutting the slot for the DVD, hopefully that will be done tonight.

Still need to decide on the finish, whether it'll stay brushed or get some polishing. Need to wire up the LEDs and power button, too.

And I've ditched the idea of adding a parallel port, since the board doesn't have a header for one. Oops.

Did have it all running last night. Full load temps are in the 40-45º C range. Not bad for only having one big fan to cool it. It should get better when I get the sides in place, there's a significant amount of air being pushed out the sides near the bottom of the board.

Might take some pics tonight if I get motivated enough.
 
Great work man. Way to stick it to those other small form factor manufacturers!
 
And some new pics.

mermini06.jpg

mermini07.jpg

mermini08.jpg

mermini09.jpg


Still need to wire up the LEDs and power button, cut and fit the sides, and figure out the finish.

And so far this thing is QUIET. Two feet away and the only noise is a result of drive access. Seriously, this has to be the quietest system I've ever had.

Oh, I also need to mess with the flash reader. The Compact Flash part doesn't seem to work right.
 
Heh, you're going to think I'm crazy, but I laid out a pencil line the length of the slot, drilled a ~1/8" hole at each end, and filed it out with a round needle file. Then I cleaned it up with a flat file, but it didn't need much. It only took about an hour total of filing, but I only did around 1/2-3/4" at a sitting.

One side effect of my design is that the rear corner of the case over the DVD drive isn't actually affixed to the case. Floats loose about 1/32" of an inch over the face of the drive. Because of this, I don't need an eject button on the drive. I can just press down on the case corner, which flexes enough to depress the button underneath.
 
good touch with the file;)
I did the same no button trick with the plastic face on my CrossFlo comp.

Great job on the comp.
 
Nice looking PC,

I think you may need a USB hub in there (I see only 3 ports). But if you have a monitor with a hub, you'll be fine (hey, since they get you DELL PCs @ work they should be able to get you a nice DELL monitor)

Also, get us a size comparison shot with another PC, with all that "empty space" under the fan and behind the DVD, this thing looks bigger than it needs to be.
 
Two USB on the back, one for the flash reader, and a 4th on the flash reader itself. I'm good for USB ports, only going to need them for a wireless receiver for the keyboard/mouse, UPS, and maybe a printer. The printer will probably end up being networked off another PC, though, so I'm not too worried. As for the monitor, I already have a dual 15" LCD setup at work. I also have a "spare" 20.1" widescreen at home that I think will be modded to match this system.

If I do need a hub, I can always bring in this one.

And it is larger than it needs to be. The breadbox I cut it out of was taller than I wanted, but that allows me to keep the fan hidden in the bracket AND keep the fan up high enough that it can pull in air without any restriction. If it were lower, I'd be worried it might make noise from fighting to pull air through a smaller opening.

The extra depth is a result of the curve on the front of the case, had to be set back at least an inch. The depth could only have been cut down around 1/2", which was kind of pointless. I also could have narrowed it about 3/4", but I was also worried about being too narrow and shallow with the height and top-heaviness. Last thing I wanted was a PC that was going to fall over if someone bumped the desk.
 
Well, I've been dealing with random crashes and bluescreens over the last day. Swapped out memory, unplugged devices, nothing seemed to fix it. Under a load it would always fail around 5-6 minutes. Changed CPUs. I've got a 1.86GHz T5600 from another project, and dropped that in place of the T7400ES I was running. It's a happy-sad situation. No more crashes, but I've got a CPU with a problem and less cash in my pocket. I also have a slower system with less cache, too.

Guess it's time to sell off more junk. Maybe splurge on a T7600?
 
Part of the risk of engineering samples, no one there to guarantee it will work or not. I've got it running with the T5600, so I know there's nothing goofy with the board. Wish I had another way to test the T7400.

I also wondered if it was a power issue, but still got the crashes when I swapped out the 60 watt power brick I had been testing with for a 100 watter.

Another thing I'm noticing is that the slower chip shows HOTTER temperatures in CoreTemp than the 300MHz faster chip. Think I need to pull the heatsink off and redo the thermal compound.

Also considering throwing on a different heatsink. Using one with closely spaced fins and I don't think the fan has enough pressure to effectively move air through it. I may swap the heatsink from this one for the heatsink in a Celeron-M DFI-motherboard system I have. That has a larger heatsink with wider spaced fins, but it's also aluminum. I really don't think that will matter, we're only talking 35 watts on the CPU after all.
 
Been letting the system run for the last 4 days, trying to shake out any hardware issues before I continue. Tomorrow night I'll be tearing it down. Need to trace contours for the side panels and get started on the metal finishing.

If I get of my ass and get to work I could be done after this weekend. Just need to decide what material I'm using for the sides...
 
And this has not been abandoned, just got caught up in some other things.

Left to do...
- Side panels, have my material, just need to cut it to fit.
- sand, sand, sand, and then figure out how to keep the finish from looking too awful. Clear coat?
- Swap out the CPU, picked up a T7200
- Install a permanent OS, more than likely XP64

Honestly, that's about all. Bought a keyboard that matches nicely and feels pretty good, too.

I'll get pics of the setup when it's complete, don't know how many I'll be taking before then. Have to finish a few paying projects before I really go back to finish this for myself.

I did get a chance to do some power measurements. Under a full load with the T5600, the system pulls 48 watts. Should be under 60 watts even with the T7200, probably even with a T7600.
 
Couple new pics, got the sides cut and installed. Still have the guts out, want to sand out the finish a bit more. I'm really doubting I'll do much more, though. There are just too many DEEP scratches that I can't get out without removing a lot of material. As of right now it looks good from 2 feet away, and I doubt anyone will ever get much closer than that.

mermini10.jpg

mermini11.jpg

mermini12.jpg
 
I've given up on sanding out any more scratches, some are just too deep. I could keep going, but I'm itching to wrap this up. Also decided to let it "age" instead of trying to maintain the freshly sanded look. With the still visible scratches I think it's a better option. Just need to wipe it down every so often to keep fingerprints from showing.

Going to load it back up tonight, I think, then hopefully get the OS installed one of these days.

Sad thing is once I get this done, I don't really have anything new planned. Got a stash of embedded boards, but really haven't had any good ideas for them. I do have an LCD I'd like to mod, but that'll probably just end up being a paint job.
 
No putty and painting, I wanted a brushed finish and I've got it. It's just a bit more "brushed" than I wanted.

Put all the components back in last night and had it running for a short time. Temps aren't much(if at all) higher, and the side panels have even muffled the drive noise a little. Just need to get an OS onto it now.

And I've pretty much decided this isn't going to my job right now. I need a parallel port for a printer, and this setup has none. I'd use a USB converter, but the printer doesn't much care for that. The other option is a print server or hooking it to another PC. Neither of which works since that's more stuff in my office or the printer out of the area where I need it.
 
You should anodize it yourself... Sand her down a bit first, to get a nice brushed grain (800 grit is good for this) and hard-anodize it grey like the Lian-Li cases.
 
Not gonna happen. I sand any more and there won't be enough left to anodize, just have a pile of dust at the end. Besides, it's all together and I really don't want to pull it apart again. Got everything just so, lots of cables squeezed into a pretty small area.
 
Have a temp install of XP64 on it right now for power usage testing. During install it was bouncing between 48-54 watts. Idling at the desktop it's at 24 watts. That's less than my monitor, which makes me giddy. Might be able to get that down a bit, need to tweak a few things with RMClock. It's dead quiet when running, loudest component is the DVD drive. Hard drive is pretty well inaudible from two feet away, only the slightest noise when being accessed. Extremely happy with how this one has turned out.

I'll be installing Windows Home Server on it this weekend and will take some final pics as well. If WHS runs well, this will probably end up on my desk at home as a media server. So far I like what I see.
 
And some final pics. No visual changes from this point on. I might uprgade the RAM to 2GB when prices come down, same for the CPU. Sort of considering using this as my HTPC with an external USB tuner. I currently have it running Windows Home Server, but this is a bit overkill for that.

mermini13.jpg

mermini14.jpg

mermini15.jpg

mermini16.jpg

mermini17.jpg

mermini18.jpg

mermini19.jpg

mermini20.jpg


I have to say I think it's pretty damned cool. Turned out better than I thought and the final look of it is way more than I had hoped for.
 
That looks amazing... what were the final system specs? I kinda missed that part...
 
Commell LS-371
Intel Core 2 Duo T7200, 2GHz Merom, 4MB cache
1GB DDR2-667, G-Skill
500GB Seagate 7200.10
Panasonic/Matsushita 8x Slot Load Slimline DVD+/-RW
zillion-in-1 Flash Reader
Atheros 802.11b/g wireless card with external r-sma antenna connector
Single 120mm Yate Loon 1800rpm fan for cooling
External ~100 watt power brick, 12V, 8A

I had also bought an Enermax Aurora aluminum keyboard, but it released the magic smoke after a couple days of use. I'll hold off on buying anything else until I figure out what I'm doing with this. I do have the option of using a PS/2 keyboard, but I'd have to tear it back apart and drill and file that hole on the backplate. More than likely I'll get an MS wireless set, probably an Optical Desktop Elite like I use on my primary box or the Media Center KB and remote if I go that route with the system.
 
Nice system!

I was looking to use the Commell LS-371 in a car-PC and I was wondering what power supply you specifically used. I know it wouldn't work in a car, but I am trying to gather info.

Also, what kind of power connector does the LS-371 use? Is it a standard ATX 20 pin or the newer 24 pin? Also, does it use the additional P4 4-pin 12 V connector that is found on many motherboards?

It is hard to find this info. I have tried contacting Commell to no avail...

Thanks in advance! ;)
 
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