Customizable ITX PC case for watercooling with a single 200mm fan/radiator

Cooling a CPU+GPU water loop with a single 200mm radiator/fan was a concept I proved with my last 3D printable case. It was time for an upgrade, and I wanted to design something with more hardware compatibility and customizability. I liked the “flipped” concept that integrated the GPU waterblock flush with the top of the case, so I kept that as a core design feature. This case also integrates the PSU flush with the side panel in a similar way. The bonus side effect is that this case fits full size ATX power supplies, which tend to be cheaper than their SFX counterparts. The volume of this build is about 17.7L.

During stress tests I haven't seen the water temperature go over 45c. This is with my ~120w CPU + ~300w GPU. I haven't tested any configurations with higher power loads than that yet. Even at 100% fan speed, the NF-A20 barely makes any noise. The noisiest part of the previous build was the built in DDC pump in the CPU block, but this build allows for a standalone pump, and I went with the nice and quiet VPP apex.

I ran Doom the Dark Age's full demo benchmark loop for exactly an hour.
I started the run with my ambient room temp at 22.6c and my water temp at 26c.
At the end of the run my ambient room temp was 23.1c and my water temp at 40c.

Max temps:

CPU: 86.5c
GPU: 44c
GPU hotspot: 61c
VRAM: 75c

Non-printed parts:

• Alphacool NexXxoS Monsta Full Copper 200mm Radiator
• Any 200mm fan with 185x185 mm, 165x165 mm, or 155x155 mm mounting holes. My build uses a Noctua NF-A20 PWM chromax.Black.swap.
• A Bykski pump top paired with any D5 compatible pump. My build uses an Alphacool VPP apex pump.
• A 4 pack of 200mm length 2020 aluminum extrusions
• 4x ½" 6/32 screws
• 8x 16mm M6 screws
• 2x 8mm M4 screws
• 2x 10mm M4 vibration isolators
• 20x 6mm M3 screws
• 4x 16mm M3 screws
• 6x M3 nuts
• 6x M3 T-nuts
• 4x 10mm M3 standoff/spacers
• A graphics card with a length under 200mm after waterblock installation. My build uses a Sapphire Pulse AMD Radeon RX 9070 XT. The waterblock is an Alphacool Core RX 9070 XT Hellhound + Pure with Backplate.
• Any standard ATX power supply with length of 160mm. My build uses a Corsair RMx Series RM750x ATX Power Supply with custom short cables, which I'd recommend making/buying.
• A 12mm power button. My build uses this one.
  Any CPU. My build uses an AMD Ryzen 7 9800X3D.
• Any CPU water block. My build uses an Alphacool Core 1 LT Aurora Acrylic.
• Any ITX motherboard. My build uses an Asus ROG STRIX B850-I
  gaming wifi.
• Any RAM. My build uses G.SKILL F5-6000J2836G16GX2-FX5.
• Any fittings and tubing as needed to connect the loop together.

Customizing:

Different lengths of graphics cards can be accommodated by using different lengths of 2020 aluminum extrusion. The extrusions need to be longer than the graphics card. For example, My graphics card is 197mm long after installing the waterblock, so I ordered a 4 pack of 200mm aluminum extrusion pre-cut.

2 printed parts will need to also be modified if a different length of extrusion is used. The Tray Top and the Side. The current STLs are for 201.5mm long extrusions (the actual measured length of the “200mm” extrusions I ordered).

The Side part can also be edited to accommodate different lengths of ATX power supply.

The Plate part is also meant to be customizable for additional IO if needed. Right now it just has a hole for a 12mm power button, but a 16mm button could work too with an edit. I also left space for a reset button, USB port, or whatever else could be useful. I just have vent slots taking up the extra space for now.

I included a .blend file if you are familiar with mesh editing in blender and want to edit the parts yourself. You can also comment or send me a message with dimensions and I can probably upload alternative STLs pretty quickly.

The Pump Bracket STL is meant for a specific D5 pump top made by Bykski. The extrusion the pump is mounted on is lined up with the G1/4" ports of the radiator in a way that hopefully allows for use of other pumps/pump tops with a bit of creativity. Alternatively, you could opt for a CPU block/pump combo and not have to worry about it.

The use of 2020 extrusion allows for all kinds of additions and modifications. I scaled and printed this 2020 extrusion profile model to add a bit more accent color. Other possibilities could include TPU feet, handles, brackets for 2.5" drives, etc.

Printing:

All parts are already in the orientation they need to be to print without any supports. The largest parts (radiator bracket and IO bracket) require a bed area of at least 234mm x 220mm.

I used my single toolhead Prusa XL with a 0.4mm nozzle for all parts.

The part in my build are printed in Overture PETG using the Overture PETG filament profile in Prusaslicer. 0.2mm layer height and 15% gyroid infill.

Assembly:

Unless they came with threads, You will probably need to tap the threads on both ends of the center hole on each 2020 section. My extrusions came with 5mm holes, which can be tapped for M6 threads. The radiator bracket and IO bracket are designed for M6 hardware. I've worked with 2020 extrusions that had 4.2mm holes that needed an M5 tap. I can provide STL files for M5 screws if requested.

Attach the first piece of aluminum extrusion to the top hole of the radiator bracket using a 16mm M6 screw.

Attach the Radiator bracket to the radiator using 4x 6mm M3 screws.

Attach the remaining 3 pieces of extrusion to the bottom of the radiator bracket using 3x 16mm M6  screws.

Insert 2x M3 nuts into the slots on the corner of the IO bracket.

Finish the frame by attaching the IO bracket to the 4 open ends of the extrusions using 4x 16mm M6 screws.

Install the 12mm power button into the plate.

Attach the plate to the IO bracket using 4x 16mm M3 screws and 4x M3 nuts.

Attach 4x 10mm M3 standoff/spacers to the tray parts using 4x 6mm M3 screws.

Loosely attach 4x M3 T-nuts to the tray parts using 4x 6mm M3 screws.

Create the motherboard tray by inserting the tray parts into the 2020 extrusion slots as seen below. Slide both parts up against the IO bracket and tighten the M3 screws attached to the T-nuts.

Install the motherboard on the standoffs using 4x 6mm M3 screws (I used thumb screws for these).

Install the graphics card. Use 2x 6mm M3 screws to attach the IO card's IO bracket to the the printed IO bracket by threading them into the M3 nuts inserted earlier (I also used thumb screws here).

Install the power supply using 4x ½" 6-32 screws.

Run your wires. Power supply, fan, RGB, etc. The remaining hole on the Radiator bracket is meant for running the fan cable through.

When you're done with cable management, the side can just pushed into the 2020 slots. No hardware needed.

If you use the same pump top as my build, screw the male ends of the 2 vibration isolators into the pump top, and then attach the pump bracket to the female ends using 2x 8mm M4 screws. Next I would recommend plumbing the pump inlet to the radiator so you know where along the 2020 extrusion the bracket needs to be mounted. The connection can be made with a single male to male fitting, but I opted for a short hose connection to help decouple the pump vibrations from the chassis. Use 2x 6mm M3 screws and 2x M3 T-nuts to secure the pump and bracket to the extrusion once you know where it needs to be mounted.

The rest of the plumbing and all other extras or modifications are up to you!