The original site shows reusing a complete filament paper box on the wall. This model uses left and right full-bottom halves, two matching printed short shoulder axles below the paper box bottom, removable shoulder retaining caps and two lift-off retaining caps, so the whole box slides out horizontally once the front flap drops. Set by the paper box's maximum envelope and measured solid wood thickness; the printed axle, fixing and paper box strength all need real verification.

Listed part dimensions are outer bounds; usable interior space is given in this model's specifications.

The ZIP contains the complete STL and STEP files, a size list and notes. Version 1.0.1 Use the complete set of files of the same version and size for matching parts. Preview colors are for reference only; STL files carry no color.

Ranges are set by this model's structure; each combination must pass the studio's structure checks; matching parts update with the parameters.

1. Complete print list: 1 left frame, 1 right frame, 1 drop-down front flap, 2 lift-off retaining caps, 2 printed short shoulder axles, 2 printed inner spacers and 2 removable shoulder retaining caps, 11 parts in total; the dedicated axle, spacers and retaining caps are all in the STL/STEP files; no custom or cut metal is needed.
2. Required separately supplied BOM: 1 complete closed paper box, 4 Screw-Tite Ø4×20 mm PZ2 pan-head wood screws, 2 ISO 4762/DIN 912 M3×12 mm fully threaded socket head screws, 2 DIN 934 M3 hex nuts. Wood screws can be bought as SKU TFSTPZ4020, head diameter 7.6–8.0 mm / height 2.5 mm, minimum thread length 17.5 mm; M3 coarse 0.5, head Ø5.5 × 3 mm / HS2.5 socket depth 1.3 mm, nut AF5.5 × 2.4 mm; all are fixed standards that do not scale. Currently: 18 mm solid wood backboard, 8 mm printed backboard, nominal 12 mm into the wood, 6 mm from the back face. Pre-drill as the screw maker recommends; do not treat marketing claims as load verification for this rack.
3. Tool: 1 PZ2 screwdriver (reference retail Bahco 9778PZD-2: Ø6 × 110 mm blade, AF10 collar, 27 mm wide × 110 mm handle; software uses a full Ø12 × 110 mm blade including the hex collar; not guaranteed to fit a 36 mm large handle), 1 HS2.5 L-key (reference Wera 950 PKL: 112 × 18 mm, software 115 × 20 mm), 1 × 5.5 mm open-end wrench (reference BAHCO 111M-5.5: head 14.3 × 3.7 mm / length 112, software 15 × 4 mm / length 120). For standard part datasheets see Tite-Fix TFSTPZ4020/25 and Accu SSCF-M3-12-A4-R360/NUT203M3; arbitrary custom head heights or nut thicknesses cannot substitute.
4. First fix the two empty frames through the four holes to a measured thick solid wood upright, aligning the bottoms and axle holes; installation tools go in and out from the front; keep the full front screwdriver/finger path and the side retaining cap tool paths clear. Close the complete paper box with light items inside before taking it; do not put loose items directly in the rack.
5. Drop the front flap between the two fixed ears from above, and place the printed inner spacers onto the inner faces of the fixed ears from above; two printed short shoulder axles pass inward from the left and right through the fixed seat, inner spacer and door ear; the Ø8 × 3 mm shoulder rests against the outside of the fixed seat, and the current Ø4 axle has an effective length of 20.6 mm. The two retaining caps drop onto fixed seats from above, with the outer plate 0.2 mm from the axle shoulder; first place the M3 nut on the printed Ø5.4 ring ledge (ledge top Z14.2 mm) through the 4 mm high outer channel, hold the nut across the ledge with a 5.5 wrench, then insert the M3×12 from above and screw it in; the nut rises 0.4 mm under the fixed deck; do not move a nut sideways across an installed screw. Ledge 4 + lid 3 mm grip length 7, with 2.6 mm of shank past the nut; after the software deducts 1 mm at the tail, 1.6 mm of full thread remains. To take it apart, back out the screw, let the nut drop back onto the ring ledge, remove the nut/wrench sideways, lift the lid and then pull the axle; the axle shoulder and lid give nominal two-way retention, without the strength of the original metal axle.
6. Stand the front flap up against the rear stop block, drop the two retaining caps on from the top, with the cap bridges against the front flap and the stop post tops. With the two caps lifted, the front flap folds down 90° forward and the bottom stop catches it; the paper box bottom sits above the axle and open flap; pinch the front and top at the box's upper front corners with both hands and take the whole box forward horizontally; reference Ø10 × 18 mm per finger; gripping through the narrow side slit is not claimed.
7. Reference upper limit for a complete paper box 209.2 × 106.2 × 85 mm (width, depth, height); leave real-item allowance on top of the maximum outer envelope. The two base plates have a 0.8 mm nominal center gap; use an intact closed paper box, and check its strength/deformation, load and mounting safety before use.
8. The retaining cap only sits by gravity and cannot be used as a transport lock; before use, check printed axle tolerances, lid clamp loosening, rotation wear, paper box/board fixing and load. Slice with the frame back on the bed and the front flap side/retaining cap bridge faces on the bed. Print the axle along its axis and the retaining caps outer plate down; check supports and print an interface sample. Check slicing and test-print before printing; support-free printing or a safe wall-mounted load is not promised.

Import into your slicer in millimeters and check build volume, orientation and supports for each part. Test-print lids, drawers and connectors first, and print the full set once the fit is confirmed.