Steam Box 5 Fat by Old Lamer (vertical case for AMD BC-250 cooled by JF13K SI-100)

ONLY FOR PEOPLE WHO OWN 3D PRINTER AND/OR ENTHUSIAST WILLING TO TRY NEW STUFF 

MAKE SURE ALL VRM COMPONENTS HAVE INDIVIDUAL HEATSINKS (ALTERNATIVELY STOCK HEATSINK CAN BE TEARED APART AND USED FOR THAT IF YOU KNOW WHAT YOU ARE DOING :-) )

I recommend working-out all gliding male sliders with something like Scotch Brite to make sure they move easily and to prevent damage when inserted w/o sufficient care. 

UPDATE: 26SEP2026

Revised TOP-GRILLEs added. One for use with P14 top exhaust fan (flat top, increased distance to fan for noise reduction). Another for use with P14 Slim - scooped top, with better looking mesh pattern. 

UPDATE: 23SEP2026 

In Thermalright SI-100 use case test scenario system performed well w/o P8 additional cooler. Another option to explore is to reverse the P8 fan for an additional exhaust. Testing required. 

UPDATE: 16SEP2026

Lower U-shell with additional vents for use with Metalfish or similar Flex PSU that does not have vents on DC output side of PSU and needs to exhaust warm air via side contacting with Steam Box 5 rear wall. 

UPDATE: 11SEP2026

Front large panel cut to allow printing on smaller bed printers (256 and 220mm) 

UPDATE: 10SEP2026

Case version for Thermalright SI-100 CPU cooler added.

UPDATE: 09SEP2026

• Upper and Lower U-shells tested and uploaded with dove tail secure attachment;

• BC250 moved 2mm up to provide better clearance from bottom deck guides;

• both bottom decks redesigned to bring PSU closer to case rear wall;

• lower face plate for use with common jumper switch added;

• large mid mesh panel updated with spacers to maintain correct gaps between low mid and upper face panels;

• base stand updated with lip to support lower face panel from sliding.

UPDATE: 08SEP2026

New U-shells with dove tail type connection added. Provides more robust securing of two U-shells together. Requires volunteers to test print these and confirm all ok (as I'm currently away from my 3D lab). 

BC-250 Steam Box 5 — Custom Vertical Console Enclosure

A custom 3D-printable vertical enclosure designed specifically around the AMD BC-250, combining the design language of classic Steam Machines with a tall, compact console-style layout.

The complete assembled enclosure measures approximately 171 × 159 × 418.5 mm, including the integrated floating bottom base. Its footprint remains only 171 × 159 mm, while the recessed base raises the main enclosure approximately 18.5 mm above the desk, creating a subtle floating appearance and providing essential clearance underneath for the BC-250's downward-facing HDMI / DisplayPort connections.

The enclosure is designed around:

• AMD BC-250 board

• JF13K cooler or Thermalright SI-100 cooler

• 2× Arctic P12 Pro fans on the JF13K or one on SI-100 (stock fans work well as well :-) )

• Arctic P14 Slim 140 mm top exhaust fan

• Anker 4-port USB hub integrated into the lower front panel

• 2× M19 front buttons

• IEC mains input

• Integrated floating bottom base with an open underside for display cables

• Removable Steam logo badge

• Two alternative PSU configurations

• Additional Arctic P8 fan is foreseen for SI-100 case version

PSU Configurations

HP PL28 / PL29 Server PSU

Uses a dedicated bottom mounting deck with PSU mounting points, ventilation opening and additional clearance for the AC connector and PSU latch/handle.

Flipping PSU fan to push air into PSU instead of extracting is recommended for better performance of PSU cooling system.

1U Modular Flex PSU

An alternative configuration using a shorter modular Flex PSU, with its own dedicated mounting deck, ventilation opening and mounting geometry.

Both configurations are included in the package.

Enclosure Design

The enclosure consists of two large U-shaped structural sections, three floating front panels, a perforated top exhaust grille and the recessed floating base.

The large 280 mm center front panel is heavily ventilated and carries a separate removable Steam emblem. The lower service panel integrates the Anker USB hub and control buttons.

The top of the enclosure uses a large perforated bowl-style grille with a 140 mm exhaust fan directly underneath, creating a strong bottom-to-top airflow path through the system.

Printing Recommendations

The design is intended for printers with at least a 300 × 300 mm build plate and was developed and physically tested primarily using Creality CR-PETG on a Creality K2 Pro.

CR-PETG is my recommended standard material. It provides good toughness, some flexibility for clips and sliding joints, and considerably better temperature resistance than PLA.

For the best cosmetic result, I would recommend black PETG-CF. Carbon-fiber-filled PETG generally gives the large vertical surfaces a much more matte and uniform appearance, while regular PETG can appear glossy or semi-gloss depending on temperature and printing speed. PETG-CF also does a very good job of hiding layer lines and gives the enclosure a more factory-made appearance.

An abrasion-resistant/hardened nozzle is recommended for PETG-CF.

The visible front panels and Steam badge can be printed face-down on a textured PEI build plate, which gives the visible surfaces a very clean textured/matte finish.

Final sliding and mechanical tolerances were calibrated at approximately 0.20 mm using CR-PETG. I strongly recommend printing the included tolerance coupons before committing to the large enclosure pieces, especially when using another printer or PETG-CF.

Important — First Revision / Beta Version

I consider this release to be the first public revision and effectively a beta version of the enclosure.

I have successfully printed, assembled and operated the complete system, so this is not simply an untested CAD concept. However, this is still a complex DIY enclosure with many interacting printed parts, hardware tolerances, cables and component variations, and there may still be small caveats or fitment issues that I have not encountered during my own build.

Because of this, I strongly recommend this model primarily to people who own a 3D printer and are able to print, test, adjust and reprint individual parts themselves.

If you are considering paying a third-party printing service to manufacture the entire enclosure for you, I would suggest waiting for additional community builds and feedback first. A complete enclosure involves a significant amount of filament and printing time, and I cannot yet guarantee perfect fitment with every printer, filament, BC-250 revision, PSU, cable or accessory combination.

In other words:

Print it as a DIY project, test-fit the parts, and expect the possibility of minor adjustments. Do not treat this first release as a finished mass-production commercial enclosure.

Feedback from other BC-250 owners is very welcome, and future revisions can be improved based on real-world builds.

Assembly Instructions

The enclosure is designed to go together in a fairly simple sequence. I recommend doing a full dry-fit before final cable management.

1. Join the two main U-shells
   Align lower_u_shell.stl and upper_u_shell.stl and connect them to form the main 400 mm-tall enclosure body. Make sure the internal guide rails and front-panel channels line up correctly.

2. Install the PSU on the bottom deck
   Choose the correct bottom_deck.stl for your PSU version:

   • HP PL28 / PL29

   • 1U Modular Flex PSU

   Secure the PSU to the dedicated mounting points on the bottom deck. Install and route the required AC/power wiring before access becomes more restricted.

3. Insert the bottom deck
   Slide the PSU + bottom_deck.stl assembly into the lower U-shell using the internal horizontal guide rails. Make sure it is fully seated in its intended position.

4. Install the AMD BC-250
   Carefully place the BC-250 board inside the enclosure and align it with the dedicated mounting supports. Secure the board using the appropriate screws at the provided mounting points.

5. Prepare and install the top fan carrier
   Attach the Arctic P14 140 mm fan to fan_carrier.stl.

   Once the fan is secured, slide the complete fan-carrier assembly into the upper section of the enclosure using its guide rails.

6. Install the upper front panel
   Carefully slide upper_front_panel.stl into the vertical front guide system from the open top of the case.

7. Install the main perforated front panel
   Fit the steam_logo_badge.stl to front_mesh_panel.stl if it has not already been installed.

   Then carefully slide the complete perforated center panel into the front rails underneath the upper panel. Make sure it moves freely through the internal crossing points and is fully seated.

8. Prepare the lower service panel
   Install the Anker 4-port USB hub and both M19 buttons into lower_front_panel.stl.

   Connect the required wiring before installing the panel, as access will be more limited afterward.

9. Install the lower front panel
   Slide the completed lower_front_panel.stl into the bottom section of the front guide system until it reaches its final position.

10. Install the floating base
    Fit floating_base.stl onto the bottom of the enclosure. The base supports the lower front panel and provides the required clearance underneath the BC-250 for the downward-facing HDMI / DisplayPort cables.

11. Place the enclosure upright
    Once the base is properly seated, carefully turn the complete enclosure into its normal vertical operating position.

12. Install the top grille last
    Fit top_grille.stl as the final exterior component. Slide the grille into its captive guide system from the rear toward the front until it locks into its final position.

Cooling / Performance From My Build

The cooling system has performed very well in my completed build.

My BC-250 is running with:

• 40 Compute Units at up to 2.0 GHz @ 960mV

• 8 CPU cores unlocked

• CPU running at approximately 4.0 GHz @ 1275mV

• JF13K cooler

• 2× Arctic P12 Pro fans on the JF13K

• 1× Arctic P14 140 mm top exhaust fan

In gaming workloads, I have been seeing temperatures generally in the mid-50°C range, while maintaining what I consider a relatively low and comfortable noise level.

The Arctic fans are daisy chain connected and are limited in BIOS to approximately 70% maximum fan speed.

These numbers are from my particular BC-250, fan configuration, tuning and ambient conditions, so they should be treated as a real-world reference rather than a guaranteed result for every build.

Included Files

The package includes:

• Complete STL print set for HP PL28 / PL29 PSU  and  1U Flex PSU

• Floating bottom base

• Steam logo badge

Overall assembled dimensions: approximately 171 × 159 × 418.5 mm
Footprint: 171 × 159 mm

A compact DIY BC-250 console built around the actual hardware — properly engineered, highly ventilated, quiet and very cool.

Heat sinks options (few of a million options :-) ):

https://www.aliexpress.com/item/4000532648266.html
https://www.aliexpress.com/item/1005008976330401.html
https://www.aliexpress.com/item/1005007391616890.html
https://www.aliexpress.com/item/1005005202554577.html