Zds Project Log

These are the built-in controller knobs of the Scythe chassis fans. They are set to minimum speed and taped into upper front corner out of the way:

Assembling the parts starts with routing the front panel connector cables properly. They will be sandwiched between motherboard and motherboard tray, so rerouting them pretty much means detaching the motherboard:

Motherboard and the hard drive installed. As you can see, the chassis is just high enough that motherboard clears ODD on top and HDD on bottom:

Motherboard and the hard drive installed. The hard drive clears the motherboard by just few millimeters.

The stains on the southbridge tell that this motherboard is already on it’s second life. It served originally my personal desktop machine, but I poured white wine over it on certain party, and +12V voltage sensor and one of the DIMM slots stopped working.

Now that the previous motherboard of this machine broke, I gave it another try and was able to wash it clean. Literally wash - I removed all detachable parts including CMOS battery, washed it under tap water, dried with hair dryer and let it dry for 24h before connecting again. And lo and behold, the fourth memory slot started working. Another 70€ saved!

Hard drive mounts to aluminium sled with plastic rails. The two aluminium sleds also double as case bottom and feet:

The SATA cable for ODD is routed under the motherboard like front panel connectors. The SATA cable needs to do a tight turn - needed to be very careful here to not place too much stress to motherboard SATA header:

Opening the right side panel we see that there’s not much there. No space for anything, and thus no holes either:

Except this one, for screwing ODD in place. Notice also the steel inserts for motherboard standoffs - this is a quality case, and it shows. Aluminium is not good for screw threads, it breaks too easily and it has lot of friction. Steel inserts make sure the threads are easy to use and last some use and abuse:

One of the downsides of the M4A78-EM motherboard is that it has only two chassis headers. But it’s a solid budget motherboard otherwise, can’t get everything for just 70€.

Notice also the clearance between motherboard and ODD tray - not too much space wasted here either:

In this revision of M4A78-EM the other chassis fan header is awkwardly between IO panel and CPU cooler. This might work for cases that sport case fan in back next to IO panel, but it’s very bad for this build. Interestingly enough, on my newer M4A78-EM the headers are in a bit different locations, better, if you ask me. Different revision, I guess.

Quality case often come with details you didn’t know to ask, but which help you build better machine. And here’s one: an extra PCI slot cover. There is some amount of room behind the ODD, but not enough breathing space for anything that generates heat, so SilverStone engineers added this slot there:

The USB PCI backplate cable is *just* long enough. Remember it needs to go between motherboard and VGA card, which requires an additional turn.

Here you can also see both ends of the ODD SATA cable, routed behind the MB:

Graphics card in place. This was the only “oops” on this rebuild: on the previous motherboard, M2A-VM, VGA slot was one spot higher, on M4A78-EM it’s one spot lower.. meaning the graphics cooler fans sit very, very close to the hard drive cages.

Do note that the fans face to different directions - this is intentional. At first they blew both away from the VGA card, but that heated HDD to uncomfortable levels, so I switched it around. This hurts GPU temps a tiny amount, but very little in practise, and helps HDD a lot. And because HDD dislikes temps over 40C, while GPU can handle up to 95C, shifting some thermal load from HDD to GPU is a good deal:

This S shaped piece of acrylic is the only totally custom part on this build, and plays a crucial role:

These black tabs are rubber foam; expensive and heavy, but very good at vibration insulation. Attached with hot glue.

The air guide (the S-shaped piece of acrylic) installed. The purpose of this is twofold: First, it directs air from the front fans towards the CPU/PSU intake area and second, it keeps the cables from the non-modular PSU out of the way of the said airflow:

The air guide friction fits between front panel connector PCB and case border, with help of the rubber foam tabs:

Air guide and PSU in place. The PSU is 380W model from SeaSonic S12II series. It’s 80Plus certified and one of the first sub-400W 80Plus PSUs on market back when it was bought. And 380W is already too much for this system, but because everyone and their dog believes bigger is better this was the best fit I could find.

Air guide and PSU in place, cables in their almost final places. As you can see, there’s a lot of spare cabling to store, and this is where the custom guide really shines:

All major components in place:

Tape was used to keep power and SATA cables out of the way. The borders and corners of the case have quite a lot of room for cables, you just need something to hold them there:

The Fanmate 2 controlling VGA fans was routed to the back of the case. If you do tricks like this, keep an eye on the power ratings - the reason why I was able to pull it off is that I used small (92mm) low power fans. Anything larger would go over the max rated power supported by a single fanmate:

Here you can see the bottom of the case and the HDD caddies. They are machine aluminium extrusions that also form the feet of the case. Now that the VGA fans are blowing almost against the case floor, I’m thinking of machining a fan vent to the empty HDD tray. I just need to make sure the structural strength of the case is not compromised:

The bottom of the case and the HDD caddies. They are machine aluminium extrusions that also form the feet of the case. Now that the VGA fans are blowing almost against the case floor, I’m thinking of machining a fan vent to the empty HDD tray. I just need to make sure the structural strength of the case is not compromised.

Overall view of the completed innards. Some of the cables look like they’d be in way of airflow, but trust me, none of them actually are:

Finished!

Completed system, from front. To get idea of the size, the front grille is almost exactly the size of 2*120mm fans. You can actually see the hub of the top fan through the mesh:

It’s small and pretty, but does it perform? Yes. By stressing the system with EVE, the most consuming task she suspect her system to, we got CPU temps a bit past 60C and GPU temps a bit past 65C. When you weight in the HDD being below 35C, the system works very well thermal-wise.

It’s also quiet. Not silent, seeks of the random 7200rpm 500G WD drive are audible if the room is very quiet and you can hear medium band whoosh of turbulence when you go closer than 30-50cm of the vent on the left panel when room is otherwise quiet. However, the left panel will face to the wall, not to user, so the perceivable noise is lower. In practice the easiest way to check if the system runs is to look at the blue leds on the front, or their absence, so I consider this very successful build.

The graphics card is AMD Radeon HD3850 cooled by Arctic Cooling Accelero S1 with two 92mm Nexus fans installed on it. As we anyway need to strip the whole machine to pieces, I swap the fans and clean the heatsink:

Turns out the cleaning and swapping was indeed a good idea. In conditions like this the fan bearings will break over time, however good fans you use:

The Accelero S1 leans to the graphics card PCB with plastic standoffs seen in the middle, we need to clear then when mounting fans:

To run both VGA fans from a single Zalman Fanmate 2 I soldered together an Y splitter:

The fans are mounted by two layers (remember, we need to clear the plastic standoffs) of double-sided tape on each four corners and zip ties on two opposite corners:

Graphics card cooler with Y splitter but with not zip ties yet:

The Accelero S1 overhangs the graphics card PCB by hefty amount. Luckily this is the direction where we have plenty of space in SG03:

And now we are in this stage, as advertised:

Next and last page: putting it all together.

After the case is stripped and cleaned, it’s time to prepare the parts. Here’s a preview of where we are heading in this part, all the parts ready to be installed:

The clearance for CPU cooler in SG03 is 82mm, and the PSU on top of the CPU area can be installed two ways; intake facing either the side panel mesh or the CPU area. In the previous generation of this system CPU cooler was Zalman CNPS8700 NT, a heatpipe flower where stock fan blows towards the motherboard and PSU was installed to draw air through the side panel.

Zalman is known for creating amazing metal parts for their coolers and then pairing them up with lousy fans that are hard to replace, and CNPS8700 NT was not an exception. The fan was mediocre to begin with and after half a year of usage it started to produce annoying rattling noise even when undervolted. Most likely trying to suck air just 5-10mm from the solid back of the PSU put too much stress to bearings of a fan of questionable quality.

So, in this generation I am using Scythe Big Shuriken, a short but wide cooler that has received high praises on SPCR:

The dimensions of the Big Shuriken are almost optimal for SG03, as cooler height is limited, but due to supporting regular µATX boards, width is not an issue:

Big Shuriken comes with unique 120*10mm fan which is really, really thin:

Cleverly the fan mounting clips seem like they’d accept any open-cornered 120mm fan. This means you can use thicker fan, if you have enough clearance. Per my guesstimate 15mm or even 20mm fan would still fit SG03.

The fan was installed blowing away from the motherboard, because that way it works to same direction than PSU fan, meaning the fans work in tandem, instead of fighting against each other. Obvious downside is that PSU now breathes pre-heated air, but on the other hand PSU fan has to rotate less to move similar amount of air, because CPU fan creates positive pressure for intake side of it.

Bug Shuriken installed on the Asus M4A78-EM motherboard:

The Big Shuriken still clears all power circuitry and standard memory modules with flying colors. Memories with tall heat spreaders need not apply, tho:

Next page: Preparing graphics card for installation.

The rather long downtime is over. Expect updates real soon now - I have hundreds of photos from various projects waiting to be posted..

Yesterday I bought some aluminium-capable blades for my jigsaw, a drill press and router. Unluckily I didn’t have time to pick up my aluminium sheets and rest of the week goes into long weekend snowboarding in Lapland and preparing for it.

But on the bright side, I’ve made some progress on the case shape front:

The rightmost is my vision per today, middle one from Sunday and leftmost from Saturday. Definitely getting better.

The clay model did it’s job - it helped me to see which parts worked and which did not, resulting in a sleeker model. Huzzah.

But I better get the shape fixed soon, as I do not want to cut 130€ worth aluminium into something that does not satisfy me :-].

Starting again with foamcore:

Remember kids to sand the foamcore sheet before gluing.

Here you can see the size difference between the first iteration and the current:

I “maybe” overdid “a bit” the polyurethane foam part:

But there’s few problems that cannot be solved with sharp enough blade. Now looks a lot better:

Add some artist’s clay into the mix:

I saved some money and used the kind of clay used mostly to do ceramics and not the one used by sculptors. This means it’s more sticky and coloring, so I didn’t dare to touch the camera while sculpting.

Anyway, here’s what I ended up with:

As I’m sick third week on a row, no chance to get anything physical done. Instead I have done some math and drawn some pretty pictures.

As you might recall, the plan this far was to have water flow in thin layer between TEC hot sides and backplate, from up to down, and distribute heat to backplate while flowing. Well, I started to calculate the thermal conductivity performance and heat distribution along the heatsink and quickly decided to change the plans.

Here is the new plan:

The new thing is that the heat exchanging part (where cool and warm loops flow over the TECs) is now narrower and I have added copper pipes (the red lines) that will be embedded inside the back heatsink.

Cross section showing the two water loops and TECs (from top to bottom: cool loop, TEC, warm loop):

Here is how the copper pipe will be mounted. The idea is to take 12mm OD, 10mm ID copper pipe and squeeze it to 10×10mm groove in the heatsink:

The bottom grey part is the heatsink, top grey part is the backplate. Thus copper pipe is sandwiched between backplate and heatsink. If my calculations are correct, the pipe should fit just as well as in the picture; it’s in the exact scale. By forcing the copper pipe to deform I hope to get better contact between the heatsink and the pipe.

Here are gross estimates about temperature gradient over heatsink in the old and the new model:

Each step represents 2.5°C difference in temperature when the total heat load transferred is 250W. As the heatsink will be constructed from vertical aluminium pieces, I have assumed thermal conductivity of 150W/m/°K to the horizontal direction and 200W/m/°K to the vertical direction.

This is basicly optimization between flow resistance and maximum temperature gradient: more pipes mean less flow but better thermal transfer..

What I hadn’t realize before was that while flow resistance is roughly linear in relation to the lenght of the pipe, thermal transfer increases squarely with the pipe length. If I have reasoned properly, this is due to the fact the when you add more piping, you both decrease the average distance from each point in heatsink to the closest point of hot water _and_ increase the amount of conducting surface. The latter means that there is less thermal energy per cross section area of the heatsink to transfer.

And the last image shows how the heatsink will be constructed. The top of the image is the outer side and the bottom is the inner side. Note that most of the inner surface will be flat; this depicts the part where there is also internal heatsink:

The outer fins are optimized for passive heat transfer, thus they are thick and sparse: 2mm per fin and 10.5mm between them. Inner fins, where present, are supposed to be cooled via forced airflow, and there fins are 0.5mm thick and have 4.5mm worth space between them.

Proceeded with the second scale model. I let the images do the speaking:

The backplate and its screw mounts are sturdy enough that I consider cutting it out and using in the final assembly. This way I also save the pain of trying to find fitting metric screws to replace the original ones:

This shows why this is perfect PSU for TEC use. 70% of the rated maximum power is available in a single 12V line:

It seems that I do not want to remove the original heatsinks. They are made of single piece (each one) and screwed with some dozen, half of which are behind soldered components. Here are the only four screws I _could_ remove easily:

This component it a bit of mystery to me. It was screwed to main heatsink separately. OTOH, I have not been able to find anything resembling thermal diode:

The scalp! As I will not use any standard connectors, I cut them all away:

I also cut away lot of the power cables to reduce the clutter:

What I left is 8 +5V cables (red ones), 7 +12V cables (all there was..) (yellow), few 3.3V cables (orange) and 12 ground cables (black). The thinner ones that are together separately are standby power cables:

There was some 16 ground cables in total, but as the TECs will draw power from either 5V or 12V line at any single moment, never from the both, it’s enough to have one 5V, one 12V and one ground line per TEC module. Thus the six TECs eat up 6+6+6 wires in total, leaving all the 3.3V wires, two 5V wires, one 12V wire and six ground wires for whatever other needs I will find.

I also played with idea about replacing half of the remaining ground wires with one very thick one and using it for all the TECs.. lets see.

As you saw in the blueprints, I plan to rip the standard fans off of the PSUs and make them leaner, while offering straighter and less restrictive airflow path and external heatsinks and fans.

The first victim was the Antec 480W TruBlue PSU, which will power the TECs and some of the lights and microcontrollers.

It’s a dual-fan model, 92+80mm:

To make room for the two fans, the main PCB is split into two parts, the smaller one raising almost to meet the opposite cover:

This is bad, since I want to squeeze the PSU (sans cooling) into 150×140x60mm box.

Fortunately it’s fairly straightforward to detach it and move it to the space once occupied by the rear 80mm fan. This just means I have to lenghten the five wires connecting the two PCBs:

This PSU convinced me of Antec quality. It feels robust and solid, and has more features I could have understood to ask for. For example, it had an external Molex connector covered with plastic cap:

I remains a mystery to me what this tiny PCB between main +12V, +5V and 0V lines and external molex connector does, but it looks like Antec has tried to actually make sure the external one and internal ones will not mess each other:

And naturally there are some leds. In fact, these blue leds are the only blue element in the PSU, PSU that comes with name “TruBlue”.. I have my doubts about how that brown goo used to glue them affects the effectiveness of the heatsinks:

And here they are cut off, the external connector and its PCB and the leds along with the legacy 6-pin 3.3V connector that never actually got popular:

This PSU had more and longer connectors than any PSU I have had this far. Naturally it also had two fan only molex headers:

I didn’t cut them, since if the Antec fan controller is of any use, I might still have some use for them.

The two Dynaeon Industries fans were detached and saved for future use:

The rear 80mm fan sports also RPM sensor wire that was made available externally:

As I have the overall shape and component placement now fixed, it’s time to check that my vision about the look can be implemented.

As I have 0.8mm thick aluminium sheet and 3mm thick acrylic sheet handy, I chose to make the second scale model to 1:2.5 scale. This way the effective thickness of the aluminium matches the 2mm I have planned for the final product and acrylic thickness simulates closely enough the planned 8-10mm full scale thickness.

Especially in bending to concave shapes scale is fairly important. As with the first version it proved out to be fairly difficult, I try now to tackle that risk early on.

Enough talk, here are the images:

As it’s already quite late, I decided to leave rest of the hammering, filing and dremeling to tomorrow. The finish of the edges leaves lot to be desired, but perfection of the finish is not the point of this model. The point is to verify that the materials and shapes I have planned work together so that I can produce the same shape with same materials in full scale.

I was sick this week, so not much work or modding got done. However, I refined the new plans to the point that I can not start working with full-size model. As you can see, I went for the bottom-heavy design:

As this a bit confusing picture shows, the top decoration element is gone. What is harder to see is that I scaled the case up in size some 8% per direction, resulting in 25% more colume to fill with parts. This made it easier to fit parts and still cool them properly and retain desired case size. Now the total dimensions are 800×470x330mm.

The light magenta part between drives and backplate heatsink marks air guide for back fans.

Basic idea in cooling is that all the heat is transferred to backplate heatsink and then when necessary, fans will spin to provide additional cooling. There is two water loops, one that flows in direct thermal contact with backplate and another that’s cooled down with peltier elements.

Here you can see the two waterloops:

Dark blue marks cool water loop, dark red the warm one. Light cyan marks the cool loop reservoir/TEC block and light magenta the warm ones.

At the top, in the “horns”, are the two reservoirs. Water flows through the sides of the chassis to the bottom where the two pumps reside. Peltier elements are located between the side flow areas. When flowing downwards, the cool loop water get cooled down by peltiers and the warm water loop cools hot sides of the peltiers and further transfers the heat to the backplate.

I reasoning behind this is that as the backplate is huge and made of aluminium, which is not the best thermal conductor there is, there will be substantial temperature differences between different parts of the backplate, unless I design cooling properly. The traditional approach has been to thicken the backplate (the part that’s not fins, but mounts them), but it would need to be very thick to effeciently transfer heat through the 900mm cross length of the heatsink.

So I ended up having warm water loop flow in thin and wide layer over the backplate. This should reduce the temperature gradient significantly and thus allow better cooling.

In addition to the passive convection cooling of the backplate heatsink, there is three portions of heatsinks that can be cooled actively.

First of all, the two back (up to 110CFM) fans protrude through the backplate and when spinning, move air over both external (mostly passive) and internal heatsink. The external heatsink is massive and with thick and sparse fins, to support passive cooling.

The internal heatsink is above back fans and is attached partly to backplate and partly to HDDs. It has thinner and more tightly packed fins as it’s mainly cooled with airflow.

The third heatsink is at the bottom front and gets heat from copper tubes transporting water of the warm loop. The three front fans (slow and silent) pull air through the heatsink and then over the mainboard and display adapter.

The reason why I push _warm_ air over the mainboard is that, first of all, it doesn’t really matter, as the parts producing most heat are anyway watercooled and second, I want to keep condensation temperature as low as possible. Naturally I will utilize some thermal insulation when going to sub-zero temps, but it does not hurt to have warm air heating up the outside of the insulation layer.

The two PSUs (one for the computer parts, another for the peltiers) will be bolted to the backplate, so they should stay rather cool even without any active airflow. In case they do not, the two back fans pull air through them to be evacuated from the top of the case.

Here is image illustrating the “show” parts, ie. parts that will be constructed to look good and be visible:

The rest, naturally, will be hidden.

And finally, here is image showing the base structural elements:

These plates will mostly be 2mm thick aluminium sheet attached to each other with L-shaped brackets. They should provide robust backbone to keep the pieces of the heavy case together.

I am also planning to have double middle-plates and have hinge at the back between them. This way I could basicly split the case to two halfs, should it be necessary. As case is mostly symmetric anyway and I will have to construct the heatsink from two pieces, this halving should not weaken the case too much. And it would enable me to do maintenance to the internal parts without tearing the whole case apart.

Now I need to wait for the replies from the sellers of ready heatsinks to know whether I want to use ready one or make one myself. And get my hands on 0.5mm and 2mm thick aluminium sheets.

Forgot to mention: The next thing after I can make up my mind with the design is to make full-scale model from chipboard, foamcore sheet, dummy PC parts and cardboard. Then I shall begin replacing those model pieces one by one with real ones. This way I should have some concrete perspective on how things will look in the end most of the time.

Before I can go on, I should decide between bottom-heavy and top-heavy design.

Bottom heavy:

Top heavy:

Then next thing to decide is whether I want to use ready heatsink or construct one on my own from thick aluminium sheet.

Using ready one naturally means less work and higher price, but making your own would give more versality.

To give you some idea, here is side view with ready heatsink and one with custom construction:

Orange dots mark where heat will be transferred to the heatsink from water loop(s).

As I do not have possibility to weld the pieces, custom construction would have worse conductivity between the fins, but to compensate that, external (passive) and internal (active) heatsinks could be clamped together more tightly.

If I do it on my own, here is a top view of the design:

The idea is to have copper pipe/bar run through hole in each sheet and have wider spacing and fins on the passive side and thinner fins and narrower spacing in the active side. To have the pieces tightly against each other I will lap them and then
tighten using thread bar, similar to Zalman flower heatsinks.

If I go for top-heavy, here is cross-section from the height of the bottom edge of the MB:

The blue thing in the blueprints is Laing Delphi pump. My plan is to have 1-2 pumps and reservoir(s) in the top compartment.

Here’s a bit cleaner scetch looking from the front:

And having learned from my mistakes I decided to start with scale model. CAD programs that are available freely failed to impress me, and this way I can get even better understanding about how things will or will not fit - even to the point I can test that all the plates can be bent from stiff stuff before I do 1:1 pieces from expensive materials.

The scale is 1:5.

Constructing it:

And finished:

I still like the design. Next I will model tubing, reservoir and the pump and then the front plates. The last part will be the most challenging, I expect few iterations to get it both implementable from thick acrylic and good looking..

EDIT: Forgot to mention that the green foam is used to simulate the heatsink. I just didn’t feel like making 0.4mm thick fin simulations and the thickness is about right (10mm, ie. 50mm in full scale)..