Longbay – Framework Laptop 12 2-Bay NAS

Summary

Longbay turns a Framework Laptop 12 mainboard into a compact 2-bay NAS (292 × 136 × 96.8 mm, about 3.8 L) that keeps the board's own SSD, its expansion cards and its USB-C power input intact. Two 3.5" hard drives connect over native SATA through the board's spare Wi-Fi slot, so the M.2 SSD slot stays free for the operating system.

• Two 3.5" HDDs on sleds: each drive slides in from the end wall and blind-mates into a SATA connector, so no cables touch the drives.

• Onboard M.2 2230 SSD stays in its original slot for the OS and cache.

• Native SATA, not USB: a JMB582 M.2 A+E card in the Wi-Fi slot adds two real SATA ports.

• Four expansion-card bays still work: 2.5 GbE, two spare USB, and USB-C power in.

• 19 printed parts, designed to print without supports, all fitting a Prusa CORE One (250 × 220 × 270 mm).

• One slow-running 60 mm fan cools both drives and the board.

• Design files: Fusion model "longbay 2", Rev H.

Features

The mainboard stays whole

• The SSD slot is still free. The onboard M.2 2230 slot keeps its SSD for the OS and cache. Nothing is sacrificed to make room for drives.

• Native SATA through the Wi-Fi slot. A JMB582 M.2 A+E card gives two AHCI SATA ports at PCIe 3.0 ×1 (about 1 GB/s), with working SMART and spin-down. Wi-Fi is given up, which does not matter on wired 2.5 GbE.

• Expansion cards keep working. Bay 1 is 2.5 GbE, bays 2 and 3 are spare USB-A and USB-C, bay 4 is USB-C power in.

• Powered over USB-C. The board boots from a USB-C PD charger alone, with no battery.

Drives and enclosure

• Two 3.5" HDDs on blind-mate sleds. Drives screw to a printed sled, slide in from the left end wall and plug straight into panel-mount SATA adapters. No cables run to the drives.

• Captured sleds. A chamfer on each sled rail sits under hold-down clips on the shell wall, so a sled cannot fall out when the case is turned over. Each door is screwed to the shell, so removing a drive takes a screwdriver.

• Pull lip on each door, in the style of commercial NAS trays.

• One 60 × 25 mm fan in the right end wall exhausts both drives and the board. Intake is through matching grilles on the front and rear walls.

• Two-piece shell bolted together at the middle, with six feet. The two feet under the joint also tie the halves together.

• Slide-on lids with no lid screws. Each lid has two spring tabs that click into a groove on the end wall.

• Printed power button. A flexure in the lid presses the board's own tact switch, and a separate snap-in plunger keeps the lid able to slide in.

• Light truss decks that carry the board on five posts, 42% less material than a solid plate. Six M3 × 10 screws hold the decks down to the shells, so the board stays put if the case is turned upside down.

• Clean look: round-ended vents throughout and chamfered outer edges.

Why it is built this way

Each choice below solved a specific problem, and most replaced an earlier idea that failed.

• Keep the OS SSD, use the Wi-Fi slot for SATA. Some builds pull the SSD out of the main M.2 slot to make room for a SATA card. Longbay puts the controller in the Wi-Fi slot instead, so the board keeps its boot drive. The JMB582 was chosen over the older ASM1061 and over 6-port ASM1166 boards for reliable SMART passthrough and spin-down. A USB dual-SATA bridge is the fallback, but it is worse at both.

• 3.5" HDDs, not SATA SSDs. In September 2026 3.5" drives cost roughly $21–27 per TB, against $110–150 per TB for the cheapest 2.5" SATA SSDs. A memory shortage is pushing flash prices up through 2026. An 18 TB CMR pair is the safe choice for a mirror.

• Blind-mate sleds instead of cables. A drive slides into a panel-mount SATA adapter on a printed dock, so nothing is cabled to the drive itself and swapping a drive is quick. A tool is still needed to remove one, which stops a sled being pulled out by accident.

• Sleds are two prints, a frame and a door. A one-piece sled could not be printed without supports. Splitting it lets both parts print flat.

• One fan, not several. Early revisions had two front intake fans, and the case once had side fans as well. A single 60 mm fan at the far end, pulling air across both drives and out past the board, cut the depth from 165 to 136 mm and leaves the long sides as plain vents. A slow fan such as the Noctua NF-A6x25 keeps it quiet.

• Two shells bolted in the middle. Each half fits the CORE One bed. The left shell holds the drives and the right holds the power parts, so the halves are also the two wiring zones. The joint bosses have 45° tapers underneath, so the shells print without supports.

• Two power supplies, no converters to build. A 12 V brick feeds the drives and fan. The Framework 60 W USB-C charger feeds the board. Drives peak near 5 A on 12 V at spin-up, and the board's USB-C ports cannot supply that. A PC power supply was rejected because none makes USB-C PD and a 500 W unit at 35 W runs at about 7% load.

• No battery backup. The mainboard's USB-C ports source only 5 V, and 3.5" drives need 12 V to spin up. Backing them would need a boost converter at its limit or a second battery, so it was dropped.

• Slide-on lids with spring-tab detents. No lid screws to lose, and the lids still click into place.

• Separate power-button plunger. The first fixed peg stopped lid B sliding past the end wall. A snap-in plunger fits after the lid is on and comes out before the lid does.

• Truss decks. Replacing a solid plate with a triangulated frame roughly halved the material. The trade-off is that the deck no longer separates board air from drive air. See the limitations section. The decks are also screwed to the shells with eight M3 × 10 screws. Without them the decks and board only rest on a 3 mm ledge, and turning the case upside down would hang their weight on the expansion cards' USB-C plugs.

• Cards stick out at both ends. The 2.5 GbE card is longer than a standard card because of its RJ45 jaw. The back end was shortened, and the front end is stepped back 5 mm above the drive doors, so every card sticks out about 3 mm and the jaw sits entirely outside in any bay. No end-wall relief is needed, and cards can be pulled without opening the lids. The step has a 45° underside, so it prints without supports.

• Snap-in feet, no screws. The six TPU feet push up through holes in the floor and lock with a split barb. The earlier screwed feet left screw heads inside the shell that clashed with the SATA dock.

What to buy

Everything except the printed parts and fasteners is off the shelf. Rows marked "check first" depend on a measurement or a spec that should be confirmed on the real part before you order.

Fasteners and inserts

Tools

Soldering iron with a heat-set insert tip, 1.5 mm and 2.5 mm hex keys, a Phillips #2 driver for the 6-32 screws, a 5.5 mm spanner for the fan nuts, a short bit or offset driver for the lower SATA adapter, calipers, and a Prusa CORE One or similar printer.

Printing

All 18 parts fit a Prusa CORE One (250 × 220 × 270 mm). The design uses 0.25 mm clearance per side and heat-set inserts (M2 Ø3.2 × 4 mm, M3 Ø4.0 mm).

The parts are designed to print without supports: sleds are split into frame and door, and the hold-down clips and joint bosses use 45° chamfers instead of overhangs, and the SATA dock prints on its side. Materials and print settings are below.

Print settings

Use a 0.4 mm nozzle for every part, and start from PrusaSlicer's 0.20 mm STRUCTURAL profile for the CORE One. These are starting points, so your filament's own profile takes priority for temperatures. The 3MF files are exported in their assembly position, so rotate each part as listed.

• No supports on any part.

• Keep elephant-foot compensation on (0.2 mm) so the 0.25 mm fit clearances hold at the first layer.

• Aligned seam at the back keeps the visible faces clean.

• Print a fit test first: one foot, a 3 mm test plate with a Ø3.4 mm hole, and the plunger show whether the snap fits hold and your printer keeps the clearances before you commit to the shells.

Assembly

The order matters in a few places, and the reason is given where it does.

1. Press in the inserts. M2 inserts into the five deck posts. 4 mm M3 inserts into the four joint bosses on the power-shell side, the four door bosses at the drive shell's open left end, the two holes in each sled frame, and the eight deck hold-down points. 3 mm M3 inserts into the four dock pads on the power-shell floor. Do the door bosses now, while the end panel is out and you can reach them.
   

   

   

   
   

2. Bolt the shells together. Four M3 × 10 screws go through the drive-shell half of each joint boss into the inserts on the power-shell side.
   

   

3. Fit the drive end panel. Lower it into the open left end of the drive shell, with the grooves in its side edges over the ridges on the inside of the long walls, until it snaps in and sits on the floor. The door screws in step 9 also clamp it to the shell.
   

   

4. Fit the feet. Push each TPU foot's stem up through its Ø3.4 floor hole until the barb clicks over the floor inside. Each end foot has one stem. Each joint foot has two, one into each shell, which is why the shells are bolted first. Fit the feet before the dock goes in, so you can see each barb has locked; the joint barb at X 155.5 ends up under the dock base. To remove a foot, pinch its barb from inside.
   

   

5. Fit the fan and the DC jack. Put the fan inside the fan end wall behind the slotted grille so it blows out, and fix it with four M3 × 35 screws from outside and nyloc nuts inside. Fit the DC jack in its hole with its own nut.
   

   

6. Fit the adapters to the SATA dock with two M2 × 4 screws each. The lower adapter sits under shelf 2 with about 27 mm of headroom, so use a short bit or an offset driver.
   

   

7. Place the dock and the power board. Fix the dock to its floor pads with four M3 × 5 screws and washers, finger-tight for now. Place the SATA power board, and wire the DC jack and the fan lead to it.
   

   

8. Load the drives. Screw each 3.5" drive to its sled frame with four 6-32 × 1/4" flat-head screws, connector end towards the dock. Fix the door to the frame with two M3 × 6 screws.
   

   

9. Slide the sleds in and line up the dock. Push each sled in through the end panel until the drive mates with its adapter. Use the ±2 mm slots to centre the dock so both drives mate cleanly, then tighten the dock screws. Screw each door with two M3 × 10 screws through the end panel into the door bosses.
   

   

10. Connect the harnesses. Plug a harness onto the back of each adapter, and run the power leads over the top of the power board to its outputs. Leave the data leads pointing up.
    

    

11. Prepare the mainboard. Remove the stock Wi-Fi card and its shield, fit the JMB582 card in the A+E slot, and fit your SSD in the 2230 slot.
    

    

12. Mount the board on the decks. Lay deck A and deck B side by side and fix the board with five M2 × 4 screws: posts P1, P2 and P5 on deck A, P3 and P4 on deck B. The fan cable passes the flat cut on P5. Once screwed, the board holds the two decks together.
    

    

13. Route the flex cable along the board top, past the rear PCB edge and down through the deck B opening to the daughterboard. The model has no daughterboard mount yet; until it does, fix the daughterboard under deck B with double-sided foam tape.
    

    

14. Lower the deck assembly. Plug the two data leads into the daughterboard as you lower it, then set it on the ledge ring and fix it with eight M3 × 10 screws: two at each deck's outer-end corners and two on each deck beside the joint. All screw heads sit outside the board.
    

    

15. Fit the expansion cards through the end-wall cutouts: USB-A and USB-C at the front (bays 1 and 2), 2.5 GbE and the USB-C power input at the back (bays 3 and 4).
    

    

    

    
    

16. Slide the lids on. Lid A goes in from the drive end and lid B from the fan end, along the wall grooves, until the spring tabs click into the end walls.
    

    

17. Push the power-button plunger into lid B. Pull it out again before you slide lid B off.
    

    

18. Connect power. Plug the 12 V brick into the jack and the Framework 60 W charger into the bay 4 card, then press the button.
    

    

Removing a drive: unscrew the two door screws, pull the sled by its lip, and unscrew the drive from the rails.

Power, cooling and cabling

Two power inputs, one each for the drives and the board. The 12 V 6 A brick feeds the SATA power board, which feeds both drives and the fan. The Framework 60 W USB-C charger feeds the mainboard through bay 4. Both cables leave through the fan end, so the long sides carry only vents. The budget is about 35 W steady and about 120 W at peak, and the drives' spin-up surge (near 5 A at 12 V) never touches the board's supply.

Data path. Mainboard Wi-Fi slot, then the JMB582 card, a flex cable, a 2-port daughterboard, SATA data cables, harness plugs on the adapters, and then the drives by blind-mate. Power reaches the drives through the 15-pin leads of the same harness plugs.

Airflow. Air enters through grilles on the front and rear walls beside the drives (bands at Z 13–26 and 45–66) and through vents in the sled doors, crosses both drives evenly, and leaves through the single fan in the power shell's end wall. The board's own fan draws from a vent in lid A and exhausts through the rear grille.

Cabling notes from the routing study.

• The gap behind the bay 1 harness plug is about 6.5 mm, so the leads must turn up at once, either with a flat SATA cable or an up-angled 22-pin plug.

• The data runs are only 60–80 mm, so buy short cables, about 10 cm, rather than the usual 20 cm or longer.

• The flex cable clears the deck B pocket edge by only about 1 mm.

One-cord option. A single 12 V 150 W brick plus a 12 V to 20 V / 3 A PD source module would give one power cable for a tidier photo. The spin-up peak of about 11 A is too much for a 5.5 × 2.5 mm barrel plug, so use an XT60 or a 7.4 × 5.0 mm plug. The model uses the two-supply arrangement instead.

Known limitations and open work

The design is modelled in CAD (Rev F). These points are still open, so check them on your own parts before printing or ordering.

Limits of the design

• The main SSD slot is 2230 only. The OS and cache share one small drive, roughly 2 TB at most.

• Wi-Fi is given up. The A+E slot carries the SATA card, so the NAS is wired only.

• No drive temperature or noise measurements yet. The truss decks no longer separate board air from drive air, so confirm temperatures with a real load.

• No battery backup. See the design section for why.

To verify on the real parts

• SATA adapter dimensions may different depending on brand. The dock shelves depend on them.

• SATA daughterboard - board that carries 2 SATA connectors for the JMB582 controller - needs to be mounted, but its size depends on the producer.

Credits and links

• Mainboard model: Framework's official Laptop 12 mainboard STEP files, licensed CC BY 4.0, from github.com/FrameworkComputer/Framework-Laptop-12.

• Inspiration: firealpaca's Framework 13 NAS with battery backup, which prompted the UPS study, and BigH's FrameVault, which influenced the slide-in drive idea, the printed flexure power button and the slide-on lids.