Fixing Airflow in the SKTC A02 (Advise needed from CNC/Lasercut experts)

Snerual

Trash Compacter
Original poster
Jul 3, 2020
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Hello,

Since a few months, I am the "proud owner" of an SKTC A02:


However, as you can already guess... This case is a real oven. The top panel is completely solid right above where the CPU cooler sits:


This basically made the Noctua L12S pictured above completely unusable, since it was sitting almost flush against a solid aluminum panel... I sold my L12S and got a second hand L9a without any noticeable difference in temps. The L9a doesn't block what little ventilation holes there are, however the case still turns into a hotbox after an hour of gaming.

The GPU side panel has similar issues, the 2 80mm fans are partially blocked because there are simply not enough ventilation holes:

My initial thought was to make a 3D Model of the top and sides, add additional holes, and ask a shop to simply lasercut the additional holes into the existing panels.
However, I'm not sure how realistic this is because:
- My digital caliper is kinda shitty, and even with a good one, it would be very difficult to make an exact model with all the existing holes in the exact right place
- Even with an exact model, the existing pattern can't simply be expanded to fill out the middle since the space doesn't line up
- Transforming exisitng "short" holes into longer one is probably not feasible in terms of tolerances
- I have no idea what lasercutting in the black brushed aluminum would do to the finish. It might cause significant damage to the existing panel
- But since I am no expert on these things, feel free to correct my wrong assumptions

So onto plan B, make a completely new top panel:


I've maintained the original pattern to the best of my abilities, but extended it to cover significantly more of the top of the case. And this is where I am currently stuck because I don't know anything about CNC/Lasercutting
- Matching the original case panels in terms of colors and finish will be impossible, so whatever material I go for would need to be in a contrasting color
- I'm not confident at all about my measurements of the countersunk screw holes, both in size and position, so I think it might be safer to just omit them and add these manually afterwards somehow. This is why I'm currently thinking of having this panel made out of wood somewhere

I am however not sure if this new pattern will offer a significant enough improvement... The holes are still quite tiny compared to what you would get with let's say a mesh. Maybe I should try making the holes half a mm larger in all directions. This would however mean they don't look identical to the ones on the side panels (unless I also get new side panels... which might be a must if I want to improve airflow for the 80mm fans as well)

So if anyone has some advice for me on how to proced here, it would be very welcome. (Also a vague idea of what this mod would cost... I am based in Germany and was hoping to stay under 100 EUR all inclusive)

My next step will probably be an attempt to model the GPU side panel, though there I am even less confident in getting precise enough size and positioning of all the holes.
 
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ignsvn

By Toutatis!
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Apr 4, 2016
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I'm gonna be using a similar case, but yeah my APU is only a 35w AMD Athlon 3000G :)
 

Snerual

Trash Compacter
Original poster
Jul 3, 2020
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Update:
- Removed the countersunk screw holes
- Made the ventilation holes 0.5mm wider and taller (original is 2.5mm by 17mm, now it's 2.5x17.5)
- Added a side panel design with placeholder holes for 80mm fans. Not sure yet if I actually want/need the fan mounting holes though. Again these are countersunk on the original panels but I figured it makes sense to keep the model 2D to simplify production and if I would go for wood I guess those holes can be added manually



 
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neilhart

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Apr 18, 2017
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The size of your problem could be better understood if you shared the make/model of the CPU and GPU.

Think large openings to let the air flow. The slots shown in your post above are nice but will not do much for air cooling. Before spending money on having new panels cut, I suggest that you use card board and prototype some panels to test. If you continue to use the L9 A cooler, try cutting a round hole in a test panel, where the hole is positioned directly above the L9 A's fan.

Also on the test side panel, try two 70 mm holes position at the fans.

The fan on the CPU cooler may need to be exhausting.

The ask yourself where is the air going to exit the case?

Good modding,
Neil
 
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Snerual

Trash Compacter
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Jul 3, 2020
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Thanks for the input. I am running a Ryzen 5 3600 with a GTX 1650. I like the idea with the cardboard protoype, however cutting that many slits into cardboard manually is going to be a real pain lol. I am currently considering making the holes even wider (3mm vs 2.5mm in my current design vs 2mm on the original panel) but you have to keep in mind that my current designs are already increasing the total "open" surface of the top panel by a factor 3. Also the bigger the holes, the more I start worrying about the structural integrity of the panel.

When you say 70 mm holes at the side, you mean literally having a gaping hole with the 80mm fan completely exposed?

Regarding keeping the l9a: I am considering getting a Scythe Big Shuriken 3 or Shuriken 2, but it doesn't make sense without having modded the panel first, because the cooler fan would sit right above a completely closed off panel. The L12S Was sitting a little too close to the top panel for my liking. Big Shuriken is only 1mm less tall than L12S but with a Noctua fan I can still shave off another 2mm of that. Plus I think Noctua brown fans peeking through brown wooden panels could look quite cool.
 
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neilhart

Cable-Tie Ninja
Apr 18, 2017
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270
Well I would start with fairly large rectangular holes. Run some stress tests. Adjust hole size and shape to get the thermals that you want. These are prototypes so do not worry about appearance. You can close up holes with tape and cardboard if needed.

Yes I would start with 70mm round holes at each fan. Run your tests and see where you are.

I use Prime95 Torture Tests for 1 hour when I have the cooling where it works. If you start to blow by your target temps, stop the test and mod the mods.

Well I have L9's (several) and Scythe Big Shuriken 2 and 3 and several others. CPU air cooling is about air flow over the heat exchanger fins. You may also want to experiment with ducting the air flow. Also don't overlook the opportunity to try reversing the air flow direction.

Most of my small cases are designed for low power Intel CPUs. Your 65 watt Ryzen CPU should be doable in this case if you remove the restrictions to the air flow.

Neil
 

neilhart

Cable-Tie Ninja
Apr 18, 2017
149
270
Well I would start with fairly large rectangular holes. Run some stress tests. Adjust hole size and shape to get the thermals that you want. These are prototypes so do not worry about appearance. You can close up holes with tape and cardboard if needed.

Yes I would start with 70mm round holes at each fan. Run your tests and see where you are.

I use Prime95 Torture Tests for 1 hour when I have the cooling where it works. If you start to blow by your target temps, stop the test and mod the mods.

Well I have L9's (several) and Scythe Big Shuriken 2 and 3 and several others. CPU air cooling is about air flow over the heat exchanger fins. You may also want to experiment with ducting the air flow. Also don't overlook the opportunity to try reversing the air flow direction.

Most of my small cases are designed for low power Intel CPUs. Your 65 watt Ryzen CPU should be doable in this case if you remove the restrictions to the air flow.

Neil
 

Snerual

Trash Compacter
Original poster
Jul 3, 2020
35
34
OK so a few updates.

First, I did some Prime 95 Stress Testing with all cores at 3.6GHz at 0.9125V. This leads to slightly under 40W total power consumption as reported by Ryzen Master. Ususally, the case is in a rather large cubby where it has around 10cm "breathing room" in all directions.
- Case inside cubby: 95C after 25 minutes (at which point I interrupt the test to avoid overheating.
- Case inside cubby without lid: stabilizes around 83C
- Case without lid outside of cubby: Stabilizes around 75C

I then flipped the fan of the L9a to be exhaust. This made things only worse, basically 5 degrees extra accross the board.

Based on these numbers I would say my "goal" is anywhere between 85-90C in Prime 95 with the case in the cubby.

I also noticed that when I flip the side panel, the rear 80mm fan does not interfere with the DVI port anymore. In addition, the front 80mm fan now has a significant portion of it's area that can push air "behind" the GPU and onto the motherboard:


As you can see, I can push the fans a few mm further to the right so the left one lines up with the start of the heatsink perfectly and the right one can blow even more air into that open space. Also note the small gap behind the PSU. Here, the current side panel is completely solid. My custom side panels will have ventilation holes there. It is also juuuuuust wide enough for a 40mm fan. However, that will probably interfere with the PSU wiring.

Regarding the panels themselves, in my latest iteration I made the holes .5mm bigger in each direction still, and extended the pattern a bit more so that the top panel is perfectly symmetrical now:


I am also currently considering to forgo screw holes completely.
- The 80mm fans are better off attached to the GPU with zip ties or maybe some shroud
- Simplifies production, no stress about screw holes not lining up and the sunk holes not looking perfect
- The top panel could be held in place with thin magnet strips
- I'd still have to think of a solution for the side panels however, magnets would push them too far off the body of the case. Worst case I have to tap them myself afterwards.

And finally as for material... In my dreams the end result will have a similar fit and finish to Ghost Sheets However, most plywood I've seen online does not look nearly as nice and I have absolutely no knowledge on how easy it is to achieve such a look with lasercut wood.