Flat-pack furniture is popular because it is easy to transport and store. Fig 1 shows examples of knock-down fittings used in flat-pack furniture. [Figure: ...

(a) Four additional functional points [4 marks]

The brief specifies a flat-pack stool assembled without tools using knock-down fittings. Additional points:

1. Load-bearing capacity - the stool must support the weight of an adult (at least 100 kg) without flexing, creaking, or collapsing. Joint strength and material thickness must be designed for this load. [1]
2. Stability - the stool must be stable on a flat surface and not wobble or tip during normal use. A wide leg stance (legs splayed outward slightly or spaced at least 300 mm apart) achieves this. [1]
3. Compact flat-pack - all components must nest flat into a compact package for transport and storage. No component should protrude or require special orientation within the pack. [1]
4. Intuitive assembly - the user should be able to assemble the stool from the flat pack without any tools and with minimal instructions. Fittings should be self-aligning and the assembly sequence should be obvious. [1]

(b) Two types of knock-down fitting [4 marks]

Each fitting earns up to 2 marks (1 for clear drawing, 1 for annotated explanation).

1. Cam lock and dowel - a cylindrical cam disc is recessed into one panel. A headed dowel (bolt) in the mating panel inserts into the cam disc. Turning the cam 90 degrees (by finger or coin) locks the dowel head, pulling the two panels tightly together. No tools required for assembly. This is the most common flat-pack furniture fitting. [2]
2. Slot-and-tab connection - one panel has a rectangular slot cut through it; the mating panel has a protruding tab that passes through the slot, then rotates or slides to lock in place. A shaped tab with a wider end (keyhole shape) prevents it pulling back through. Simple, no separate hardware needed. [2]

(c) Three design ideas [12 marks]

1. Idea 1: Four-legged stool with cam locks - a rectangular seat panel (350 mm x 300 mm x 18 mm birch plywood) supported by four separate legs (each 400 mm tall, 40 mm x 40 mm beech). Each leg has a headed dowel at the top that engages a cam lock recessed into the underside of the seat. A cross-rail between each pair of legs provides lateral stability, also attached with cam locks. All parts lie flat in a slim box. [4]
2. Idea 2: Three-panel slot stool - three shaped plywood panels interlock through slots. Two identical side panels (each with a horizontal slot at mid-height) accept a cross-brace panel that slides through both slots simultaneously. The seat panel drops into notches cut along the top edges of the side panels. No metal fittings at all. Minimal parts but the slot joints must be cut very precisely for a tight fit. [4]
3. Idea 3: Trestle-style stool with push-fit pegs - two A-shaped trestle frames made from flat panels (two legs each, joined by a top rail) are connected by two cross-stretchers using push-fit hardwood pegs. The seat panel sits on top of the two trestle frames, located by shallow dowel sockets. Robust and traditional-looking but requires eight push-fit joints, which may loosen over repeated assembly. [4]

(d) Evaluation and justification [8 marks]

Idea 1 (four-legged with cam locks) is the strongest choice. Cam lock fittings are the industry standard for flat-pack furniture because they create tight, rattle-free joints that can be assembled and disassembled repeatedly without loosening. Four separate legs give a stable, conventional stool shape. The cross-rails prevent racking (sideways collapse). All cam locks are operated by a quarter-turn with a finger or coin, meeting the no-tools requirement. [2 marks for justified selection]

Idea 2's slot joints weaken the panels (material removed at the slot) and require very tight tolerances; a loose slot makes the stool unstable. Idea 3's push-fit pegs loosen with repeated use and the trestle profile is less stable than four independent legs. [up to 6 marks]

(e) Detailed final drawing [12 marks]

• Seat panel: 350 mm x 300 mm x 18 mm birch plywood, corners radiused (20 mm) for safety and comfort
• Four legs: 400 mm tall x 40 mm x 40 mm beech, slightly tapered toward the bottom (35 mm at floor)
• Each leg top: a 35 mm headed cam dowel (bolt) fixed permanently into a pre-drilled 8 mm hole
• Seat underside: four 15 mm diameter x 12 mm deep cam lock disc housings, drilled with a Forstner bit, positioned 40 mm in from each corner
• Two cross-rails: 260 mm long x 60 mm wide x 18 mm birch plywood, connecting front-to-back leg pairs at 200 mm from the floor
• Cross-rail joints: cam dowels in each rail end engaging cam locks recessed into the inner face of each leg
• Assembly sequence: insert legs into seat (cam lock quarter-turn), then clip cross-rails between leg pairs
• Flat-pack dimensions: approximately 360 mm x 310 mm x 60 mm

(f) Materials and reasons [4 marks]

1. 18 mm birch plywood for the seat panel and cross-rails - birch plywood is strong across both axes (cross-laminated grain prevents splitting), resists warping over time, can be CNC-cut accurately for the cam lock housings, and has an attractive natural grain that can be left unfinished or lacquered. [1+1]
2. Beech hardwood (40 mm x 40 mm) for the legs - beech is dense and hard-wearing, provides excellent compression strength for a load-bearing leg, takes a smooth finish that feels good underfoot, and is the traditional choice for stool legs because of its shock resistance. [1+1]

(g) Manufacturing the seat panel [6 marks]

1. Mark out the seat shape (350 mm x 300 mm with 20 mm corner radii) on 18 mm birch plywood using a pencil, steel rule, and compass for the corners. [1]
2. Cut to size using a band saw or scroll saw, following the marked lines. For straight edges, a table saw with a fence gives the cleanest cut. [1]
3. Smooth edges using a disc sander for the straight sections and a bobbin sander or sandpaper wrapped around a dowel for the curved corners. [1]
4. Drill cam lock housings - mark four positions 40 mm in from each corner on the underside. Using a pillar drill with a 15 mm Forstner bit, drill 12 mm deep flat-bottomed holes. Clamp a fence to ensure consistent depth. [1]
5. Round over edges using a router fitted with a 3 mm rounding-over bit. Run the router around all top and bottom edges for a comfortable, splinter-free finish. [1]
6. Apply finish - sand all surfaces to 240-grit. Apply two coats of clear sanding sealer, sanding lightly between coats with 320-grit, then a final coat of satin lacquer. [1]