Parametric designs,
gated before they ship.

aerochord

A musical wind instrument that (a) prints in place as one piece with no supports, (b) does not correspond to any instrument in the historical record, and (c) is only really designable/printable with an FDM machine and a computed internal geometry. The brief was an explicit stress test of the whole co-design pipeline.

Alcove rod socket

A parametric, two-part screw-together end socket for a 40 mm round curtain/closet rod spanning a recess or alcove, used in pairs: a wall boss screwed flat to each facing wall, the rod's ends plugging into knurled collars that hand-thread onto the bosses. Removing the rod for washing = unthread the collar, no tools. Brief: issue #355 (reworked from MakerWorld #1200171, a 2-part fixed-STL 25 mm holder, scaled intent not mesh).

Shai with Orin

bistable-toggle

A fixed–fixed pre-buckled arch with two stable states (bowed up / bowed down) separated by a negative-stiffness region: power only to switch, not to hold. The monostable snap of snap-cantilever-clip taken to genuine bistability.

calibration-cube

Simple dimensional-accuracy test print; also serves as the repo's starter design demonstrating the parameter conventions.

Shai with Vera

captive-spinner

A one-piece, support-free, no-assembly fidget: a rotor ring captured on a fixed post + cap, spinning about the vertical axis after you shear the break-in fusion.

compliant-gripper

A monolithic print-in-place parallel-jaw gripper. Each jaw rides a parallelogram of two leaf flexures, so the grip faces stay mutually parallel while they translate in Y. A captive push-plunger drives both jaws through diagonal edge-notches; a pre-buckled arch (the #389 solve) drops its apex tip into a valley detent on the plunger wing and holds the clamped state with zero applied force. Push the tab → jaws close in parallel → tip passes the crest and seats in the valley → held. Pull the tab → tip climbs back over the crest → flexures spring the jaws open. One piece, no supports, no assembly.

constant-force-slider

A linear shuttle that moves under ~constant force over its stroke. It rides a guide slot (print-in-place sliding fit) and is returned by a QZS spring built from two flexure families in parallel.

Desiccant Capsule

Refillable two-part capsule for loose silica gel beads, lived-in filament dry-boxes. Perforated body lets air/moisture reach the beads; screw-on lid with real threads (not press-fit) and a ribbed grip edge so it can be opened with dry-box gloves on. Must print on FDM with no supports on either part.

Extrusion Shelf Bracket

A shelf corner bracket that locks into the side slot of standard 2020 T-slot aluminum extrusion: hammer-head lugs on the back of the plate slide along the slot, so a shelf board attaches anywhere along a rail with no T-nuts and no frame teardown. Horizontal arm carries the board between 45° gussets and a front stop lip. One printable part + a fit coupon. Brief: issue #283 (design-brief, workshop-utility style).

let-folding-panel

Two rigid panels joined by a Lamina-Emergent Torsional (LET) joint: fabricated flat from one sheet, folds to 90°, zero clearance / zero assembly / no rattle. The alternative to a pin hinge when you want a fold, not a full revolution.

N.U.G.G.S.

An 80 mm-bore tunnel system for an adult Syrian hamster, built around one genderless quarter-turn port that every module carries at every end. The kit that exists today is the Bin Bridge: two bulkheads and one straight joining two enclosures through their walls, with nothing inside the cage.

N.U.G.G.S. Den

A terminal NUGGS module — the first one in the system that is not a run of bore. nuggs is the straight (the Bin Bridge); nuggs-yard is an open playpen; the nuggs backlog lists elbow / node / open module / wye, all of them still tube. This is the end-cap: a single-port rounded refuge bulb that turns the dead flat wall at the end of a run into a place to sit, hoard and hide.

Shai with Nadia

nuggs-elbow

A first-party NUGGS module: a curved (elbow) tube that routes an 80 mm-bore run around a corner, carrying the genderless quarter-turn NUGGS port (nuggs_neck()/nuggs_port() from lib/nuggs-coupling.scad) on each end, joined by a bent tube shell with a continuous, smooth bore through the bend (welfare non-negotiable). It is a consumer of the port standard, exactly like designs/nuggs: it builds one cfg with nuggs_cfg() defaults and never redefines a coupling number.

Shai with Nadia

nuggs-frieda

A Word-World module: a NUGGS straight whose midspan is made of the resident's name — FRIEDA wrapped around the tube as a structural letter cage. Functionally it is a drop-in replacement for the nuggs straight (same 160 mm face-to-face length, same port standard at the same defaults); the letters are what it is for. The brief: "like Word World the object is made of letters … the word is Frieda. you can mix case … as needed."

Shai with Nadia

N.U.G.G.S. Feeder Hopper

The NUGGS ecosystem's feeding module: a shallow gravity hopper that mates the standard quarter-turn port and holds a few days of food, dropping it into the enclosure as it is eaten. Owner refills from outside the cage through the open top port. The catalog had den, elbow, bridge, orrery and shutter-valve — all tube or refuge; feeding was the gap (scout mandate: deepen the NUGGS ecosystem).

Shai with Nadia

NUGGS open module

The first member of the NUGGS open-module family: a straight 80 mm-bore module whose midspan opens into a longitudinal window ≥ 180° with the bore's own arc as its floor. Under charter N2 an open module is one of only three things that reset a run (an open end, an open module, a turnaround node), so any layout longer than one straight requires a part like this to stay legal. Who it's for: a NUGGS owner extending a run past the 360 mm limit, or wanting a mid-run check/hand-access point without disconnecting anything.

Shai with Nadia

nuggs-orrery

An abstract, boundary-pushing NUGGS module that is only manufacturable on a dual-nozzle 3D printer (Bambu H2-series class; AMS available for color): the standard port at both ends, and outside the hamster-contact envelope a kinetic sculpture — six twisted fins carrying three captive, free-spinning orbit rings in a second material. Request: unique/abstract, dual materials using both nozzles, bonus for built-in break-away supports and other advanced techniques. NUGGS rules constrain the animal-contact surfaces; the exterior is fair game (owner's brief, this session).

Shai with Nadia

nuggs-rim-saddle

A saddle that clamps over the top rim of a glass-tank enclosure — no drilling (N9: tempered glass shatters), no adhesive — and carries one standard NUGGS genderless quarter-turn port (lib/nuggs-coupling.scad, N10: the one interlock), so a run starts from a glass cabinet the same way it starts from a plywood bulkhead. Target enclosure: IKEA Detolf (the cabinet charter N9 itself names), parametrically — every rim dimension is a parameter with the Detolf value as the default, so another cabinet is a -D override.

NUGGS shutter valve

- Bore 80 mm, wall 2.4 mm, tube OD 84.8 mm — inherited from nuggs_cfg() defaults so the valve mates with every existing NUGGS module. Every coupling number is the standard's; the coupling guards fire inside nuggs_cfg(). - Slide clearances — the battleship-tuned values lib/print-in-place.scad carries (rail 0.4 vertical / 0.5 horizontal tabs, lip engagement). Do not loosen the rail clearances (the acoustic property); tune only the door-side door_fit on the coupon. - Target printers — Bambu P2S (256 mm bed) / H2C (bigger). Gated against the smaller P2S bed. Jane runs the same hardware. - Welfare non-negotiable — when open, the shutter retracts entirely out of the 80 mm bore; the bore is continuous and smooth with no interior ledge.

Shai with Nadia

N.U.G.G.S. Turnaround Node

The NUGGS turnaround node (issue #394, charter backlog B4): the run-resetter. A module carrying the standard genderless quarter-turn port on two faces of one widened chamber, so an adult Syrian hamster can enter port A, pivot 180°, and leave port B — doubling a run back on itself. This is the module that makes layouts larger than one straight legal: charter N2 caps any continuously enclosed run at 2 × body length between breaks, and a turnaround node of clear internal width ≥ body_len_mm that is itself open to ventilated space is one of only three breaks. Without this part, no layout bigger than one straight tube is legal.

nuggs-y-splitter

A first-party NUGGS junction module: branch an 80 mm-bore NUGGS run into two paths — one inlet port, two symmetric outlets at a 60° included angle — with all three faces carrying the standard genderless quarter-turn bayonet port (nuggs_port() from lib/nuggs-coupling.scad). Branching was the one topology the ecosystem could not do; every other module is two-port single-path. A consumer of the port standard, exactly like designs/nuggs and designs/nuggs-elbow: one cfg built from nuggs_cfg() defaults, handed to every port call, never a redefined coupling number.

Shai with Nadia

N.U.G.G.S. Yard

An open-top run for an adult Syrian hamster's playpen — free-roam time outside the cage. The ask was "loops and twists, turns, branches, all the stuff to keep him busy". It is a floor-standing kit of modules the owner lays out themselves, not a fixed object.

Over-center toggle clamp

Brief #285: promote bistable-toggle's buckled-beam physics to a load-carrying print-in-place over-center toggle clamp for bench-top workholding. One PETG print, no hardware: squeeze a lever, the moving jaw closes on the workpiece, the linkage passes dead center and self-locks, and a buckled-beam arch makes the toggle bistable so it stays both closed and open with a positive snap.

Perspective Coin

John Cena carries a watch engraved on two sides: "comparison is the thief of joy" on the back (for when he doesn't feel enough) and "memento mori" on the other (for when his head gets too big) — "a keeper of perspective, not time" (as he tells it in an interview clip shared on Reddit). This design turns those two engravings into a two-sided pocket coin, plus a print-in-place flipper charm: the coin captured in a keyring gimbal so you physically flip it to the reminder you need. Tier reference: docs/advanced-techniques.md Domain 3 (print-in-place kinematics).

Shai

pip-piano-hinge

A multi-knuckle hinge that comes off the plate assembled and swinging — the Domain-3 pin-in-bore joint tiled into a real piano hinge, plus the two piano-hinge-specific defenses (xy≠z clearance, per-knuckle axial play).

pip-planetary — a print-in-place planetary gear set

A print-in-place planetary (epicyclic) gear set — sun, three planets, internal ring — printed as ONE assembled part, per brief #307: the catalog's first toothed-gear design (Domain 3 "Gears & rotary" in docs/advanced-techniques.md). Turn the sun's crank; the carrier walks round at 5:1.

pop-fidget-card

A print-in-place 1st-birthday keepsake card (brief: issue #342) themed on a bubble/"POP" party motif — built for the parents, who keep fidgeting with it after the party. Flat landscape card, displays on a shelf via a punched easel flap, with four working fidgets printed in place on its face. Hard constraint: test-slice under 2 h; target 60 min on a fast modern printer.

Shai with Poppy

preroll-elevator

A chapstick / glue-stick–style twist tube that stores and presents pre-rolls. Unscrew the hex cap-nut lid, twist the hex knob at the base → a central screw raises an internal elevator carrying 4 pre-rolls in a ring so their tops rise out the top to grab; twist back to retract, cap the lid to close and protect. Styled deliberately as an industrial hex bolt with a nut on top — the mechanical look is the point, and the interior echoes it (the elevator is literally a nut climbing a bolt).

sbc-case — vented Raspberry Pi 4 case with fan mount

A hardware-rich single-board-computer case (Raspberry Pi 4 primary target) that is deliberately the reference / stress-test design for the assembly-instructions feature (issue #158): it ships an assembly.conf declaring real vitamin: entries — board, inserts, three screw types, washers, fan — so it exercises the NopSCADlib vitamin path, the BOM collection pass, and the GPL-3.0 product-page disclosure no existing design carries.

Shai with Cass

snap-cantilever-clip

A one-piece clip that snaps onto a plate edge and holds by cantilever deflection. Push it onto 3 mm card / shelf stock, the finger cams open over the plate, springs back, and the clip grips by spring preload — removal takes ~2× the insertion force via the steep retention shoulder.

snap-clamshell-box

A clamshell box: two trays joined at a spine by a living hinge, closed by a compliant snap latch (tab-in-window). Prints flat and open, folds 180° so the openings meet, and the front latch clicks shut. One piece, no supports, no assembly.

support-free-bracket

A wall shelf bracket: an 80 × 50 wall plate fastened by 2 × M5 screws, with a 60 mm deep × 6 mm thick shelf arm, closing the cavity under the arm with a vaulted ceiling ≤ 45° so it never prints as a bridge roof. The point of the design is not the bracket; it is the demonstration that every support-needing feature can be designed out.

sushi-battleship

Battleship played with real sushi.

Sweetheart Hamster

A palm-sized (~60 mm) jewelry box shaped like a chibi hamster cradling a heart. It splits down the sagittal midline so the heart parts between the two halves — "hamster together, heart when the pieces are apart." It is a print-in-place clamshell: the two halves come off the bed as one piece, joined along the dorsal seam by a living-hinge web, and fold shut into the hamster. A heart-shaped pocket straddling the seam is the ring nest.

Shai with Rosa