The twin sliding lid uses rigid shoulder posts, large washers and a removable closing pin. The two compartments share one full lid: insert the pin to close; to take items, pull the pin, slide to either end, return to center and reinsert, with no hardware to remove. Suits splitting items into two portions on a desk, weekday spare parts and task-based pick-up; no medical safety, child resistance, food contact, sealing or transport retention is provided. Real standard hardware sizes do not scale with the box; choose screw length from the current size list.

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 1.0.0 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. Printed parts: 1 box, 3 travel-limited full lids and 3 closing pins, 7 in total; all metal hardware must be supplied separately and is not among the STL/STEP printed parts.
2. Supply 6 M3×25 mm socket head screws (shank 3, head ≤ 5.5, head height ≤ 3 mm, 2.5 mm hex drive, at least 3 mm of effective thread at the end), 6 DIN 9021 M3 large washers (outer 8.64–9, inner 3.2–3.38, 0.7–0.9 mm thick) and 6 DIN 934 M3 nuts (AF ≤ 5.5, height ≤ 2.4 mm, pitch 0.5). Never substitute plain OD7 washers.
3. First lower the lid from above along the two shoulder posts; screws go up through the open head holes at the bottom, with a large washer and nut placed on each post top in order. Tighten onto the post shoulder with a 2.5 mm hex key from below and a ≤ 8 mm outer diameter socket from above; keep 0.4 mm nominal axial clearance at the lid top and do not clamp the lid. The screw end is 0.5 mm below the outer height, the nut engages its full height and the end extends at least 0.5 mm; washers thinner than 0.9 mm add spare thread without changing the post shoulder position.
4. Insert the closing pin with the whole lid centered; to take items, pull the pin straight up, then slide along Y to either end (±31.4 mm travel). At this point only the matching compartment of the group is exposed; the other stays covered; return to center and reinsert the pin; no need to remove the guide post hardware. The end slots stop it pulling further, and the large washer stops it lifting. To remove the whole lid, first remove the top nut and large washer.
5. Each compartment clear width × depth × height under the lid: 38 × 28.2 × 21.7 mm; the floor is 2.8 mm. Reference: small 8 mm cubes, 4 per compartment with room to pick them up; still measure the maximum item envelope from your actual items. Leave another 31.4 mm in Y at the open end, and room above the pull pin for its length and your fingers.
6. Print the box bottom, lid bottom and pin bottom each facing down; check the tops inside the screw head holes and the shoulder post round holes when slicing; check slicing before printing, and test-print to check clearances, thin slot edge strength, friction and long-term retention.
7. For portioning two sets of dry small items on a desk. Tablets are an application scenario only; no medical safety, child resistance, food contact, sealing or leak-proof transport is promised; the pin can be pulled out deliberately and has no tested anti-tip retention; use outer packaging when carrying.
8. Suggested colors: cream/lake blue/coral, slate/mustard/indigo, sage/apricot/terracotta, berry/light pink/cream, lavender/lime/misty purple, deep sea blue/mint/sand. Colors are for display only and do not change manufacturing size.

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.