Design & Technology 0445 | Paper 1 Mock 01 | Product Design

(a) Four additional functional points [4 marks]

The brief specifies a hand-operated shredder using gear-driven rollers for A4 paper. Additional points:

1. Full A4 width acceptance - the feed slot must accept standard A4 paper (210 mm wide) without folding or trimming. The internal cutting width must be at least 215 mm. [1]
2. Sufficiently narrow strips - the cutting mechanism must produce strips approximately 4-6 mm wide, narrow enough to prevent reassembly of the document for confidentiality. [1]
3. Collection bin - a removable bin or bag beneath the cutting rollers catches the shredded paper. It should be easy to remove, empty, and replace. [1]
4. Finger safety - the paper feed slot must prevent fingers from reaching the cutting rollers. A perforated guard plate or narrow slot (5 mm) achieves this while still accepting paper. [1]

(b) Two methods of transmitting rotary motion [4 marks]

1. Direct spur gear mesh (1:1) - two spur gears of equal size (e.g., both 30 teeth) on parallel shafts. Meshing gears rotate in opposite directions, making both rollers pull paper inward simultaneously. The equal ratio means both rollers turn at the same speed for an even feed. Simple and reliable. [2]
2. Compound gear train with idler - the crank drives a small pinion (15 teeth) meshing with a larger idler gear (45 teeth) mounted freely between the roller shafts. The idler meshes with a gear (15 teeth) on the second roller shaft. The idler reverses rotation direction so both rollers pull inward. The compound ratio can be chosen to adjust speed. [2]

(c) Three design ideas [12 marks]

1. Idea 1: Box-shaped shredder - a rectangular housing (240 mm x 150 mm x 100 mm) with two parallel steel rollers. Each roller carries interlocking cutting discs (40 mm diameter, 4 mm wide) at 6 mm intervals. A crank handle turns one shaft; two equal spur gears (30T) mesh the shafts for counter-rotation. A removable HIPS bin clips underneath. [4]
2. Idea 2: Clamp-on desk shredder - a G-clamp attaches a narrow shredding frame (220 mm x 80 mm x 60 mm) to a desk edge. Two grooved aluminium rollers (30 mm diameter) pull paper through, driven by a top-mounted hand crank via a bevel gear pair converting vertical crank motion to horizontal roller rotation. A cloth bag hangs below to collect strips. [4]
3. Idea 3: Tabletop hopper unit - a wide wedge-shaped hopper guides paper into the rollers. A single large gear (60T) on the handle shaft meshes with two smaller gears (20T each) on the roller shafts for counter-rotation. The 3:1 ratio gives fast feed but requires more effort. Cutting discs laser-cut from 2 mm mild steel. Folded aluminium housing. [4]

(d) Evaluation and justification [8 marks]

Idea 1 (box-shaped) is the strongest choice. The direct 1:1 spur gear drive is the simplest and most reliable mechanism, requiring low effort from the user. The box shape is inherently stable on a desk, and the removable vacuum-formed bin is easy to empty cleanly. The interlocking disc arrangement provides effective strip-cutting. The design uses standard sheet materials and commercially available gears, making it realistic for a school workshop. [2 marks for justified selection]

Idea 2's bevel gear pair adds complexity and the cloth bag is messy to empty. Idea 3's 3:1 ratio means the user exerts three times more effort on the handle, making continuous shredding exhausting. [up to 6 marks]

(e) Detailed final drawing [12 marks]

• Housing: 240 mm x 150 mm x 100 mm box from 1.5 mm sheet mild steel, bent and pop-riveted at corners
• Two internal cheek plates: 150 mm x 100 mm x 3 mm mild steel, riveted inside the housing to support roller bearings
• Two roller shafts: 8 mm diameter silver steel, 260 mm long, running through ball-bearing bushes (8 mm bore) pressed into the cheek plates, 40 mm apart centre-to-centre
• Each shaft carries twenty cutting discs: 40 mm outer diameter, 4 mm thick mild steel (laser-cut), separated by 2 mm spacer washers. Discs on one shaft interlock with gaps on the other at 0.5 mm clearance
• Discs and spacers secured by a collar and grub screw at each end
• Paper guide slot: 215 mm x 5 mm in the top plate, directly above the roller nip point
• Finger guard: 1 mm perforated steel sheet, fitted 20 mm above the rollers
• Each shaft carries a 30-tooth spur gear (module 1.5, 45 mm pitch diameter) meshing with the adjacent shaft's gear
• Crank handle: 100 mm long, 6 mm diameter steel rod bent at 90 degrees, with a 25 mm diameter x 40 mm long freely rotating plastic sleeve grip, secured to the front shaft with a grub screw
• Collection bin: 230 mm x 140 mm x 200 mm, vacuum-formed from 1.5 mm HIPS, sliding into guide rails on the housing underside

(f) Materials and reasons [4 marks]

1. 8 mm diameter silver steel for the roller shafts - silver steel is very hard, can be ground to a precise diameter for smooth running in the bearings, and resists wear from paper friction and disc contact over prolonged use. [1+1]
2. 1.5 mm mild steel sheet for the housing - strong enough to support the bearings and rollers rigidly without flexing, easy to bend and pop-rivet in a school workshop, and gives a solid, professional appearance. [1+1]

(g) Manufacturing a cutting disc [6 marks]

1. Mark out a 40 mm diameter circle on 4 mm thick mild steel plate using dividers and a centre punch for the compass point. [1]
2. Drill the centre hole (8 mm) using a pillar drill with an HSS bit. Clamp the plate securely to the drill table and use cutting fluid to prevent overheating and work-hardening. [1]
3. Rough cut the disc using a hacksaw, cutting approximately 2 mm outside the marked circle. [1]
4. Mount on a mandrel (8 mm rod) and secure in a metalwork lathe chuck. Turn the outer edge to 40 mm diameter using a right-hand turning tool. Take light cuts (0.5 mm depth) at approximately 400 rpm with cutting fluid. [1]
5. Face both sides to ensure they are flat and parallel, using the same lathe setup. This is critical for the interlocking arrangement to work without jamming. [1]
6. Remove and deburr all edges using a smooth flat file. Check the diameter with a vernier calliper (should read 40.0 mm +/- 0.1 mm) and the centre bore with a plug gauge. [1]

(a) Four functional points [4 marks]

1. Transparent front panel for visibility — The primary purpose of a display case is to showcase trophies and medals to visitors. A clear front panel (glass or acrylic) allows items to be seen from a distance while being fully enclosed and protected from dust and accidental contact. [1]
2. Security against tampering or theft — The case will be in a public corridor. A lock or secure fastening (key lock, combination lock, or tamper-proof screws) prevents unauthorised opening, protecting valuable trophies and ensuring the display remains as arranged by staff. [1]
3. Adjustable shelves for different trophy sizes — Trophies range from small medals (50 mm tall) to large cups (400 mm or more). Shelves must be adjustable in height using shelf support pins in pre-drilled hole columns, so the case can be reconfigured as new trophies are won and the collection changes. [1]
4. Dust protection — Open shelving accumulates dust quickly in a busy school corridor. The sealed case keeps contents clean, reducing the maintenance effort of regularly polishing trophies. Tight-fitting door seals (rubber or felt strip) prevent dust ingress even when the corridor is busy. [1]

(b) Two wall-mounting methods [4 marks]

Method 1 — French cleat system: Two interlocking bevelled timber strips are used. One strip (45-degree bevel on the top edge) is screwed horizontally to the wall using heavy-duty wall plugs and coach bolts, ensuring it is level. A matching strip (45-degree bevel on the bottom edge, mirror image) is screwed to the rear of the case. The case is hung by hooking the case cleat over the wall cleat; the bevelled faces interlock under gravity. This method distributes the load across the full width of the cleat and allows the case to be lifted off for rearrangement. It also self-levels because the case can slide sideways along the cleat. [2]

Method 2 — Heavy-duty mirror plates: Metal mirror plates (L-shaped brackets with keyhole slots) are screwed to the top and bottom edges of the case. Screws are driven into the wall using rawl plugs. The keyhole slots allow the case to be hung by sliding down over the screw heads. Two plates at the top bear the weight, and two at the bottom prevent the case from swinging outward. This method is simple but the individual fixing points concentrate load, so the wall fixings must be rated for the full weight of the loaded case. [2]

(c) Three design ideas [12 marks]

Idea 1 — Tall, narrow cabinet with single glass door and medal rail: A vertical cabinet (1200 mm tall x 500 mm wide x 300 mm deep) with a single hinged glass door. Three adjustable internal shelves hold trophies. A horizontal rail with small hooks runs across the top interior for hanging medals on ribbons. The narrow profile suits a corridor where width is limited. A small key lock secures the door. [4]

Idea 2 — Wide, shallow wall-mounted case with sliding glass panels: A horizontal case (1500 mm wide x 600 mm tall x 200 mm deep) with two sliding glass panels that bypass each other, allowing access to the full interior without a door swing. Three tiered shelves display items at different heights. The wide format displays more items at eye level. Sliding panels require accurate top and bottom tracks to run smoothly. [4]

Idea 3 — Modular interlocking cube units with individual acrylic fronts: A set of separate cube boxes (each 300 mm x 300 mm x 300 mm) that stack and interlock using dowel pegs. Each cube has its own clip-on acrylic front panel. Cubes can be added as the trophy collection grows. This modular approach is flexible but individual front panels are less secure than a single locked door, and the visual effect of many small boxes may look fragmented. [4]

(d) Evaluation and justification [8 marks]

Idea 1 (Tall narrow cabinet) — Strengths: single lockable door provides good security; narrow profile suits a corridor; medal rail at the top is a dedicated display feature; adjustable shelves accommodate trophy height changes. Weaknesses: the narrow width limits the number of items visible at eye level.

Idea 2 (Wide shallow case) — Strengths: wide format displays many items at eye level; sliding panels avoid door swing in a busy corridor. Weaknesses: sliding track mechanism is complex to manufacture accurately; two panels mean twice the glass area, increasing cost and weight.

Idea 3 (Modular cubes) — Strengths: expandable as the collection grows; each cube can be removed for rearrangement. Weaknesses: multiple acrylic fronts are less secure than a single lock; the segmented appearance may look untidy.

Chosen idea: Idea 1. The tall narrow cabinet provides the best balance of security (single key lock), visibility (glass door displays all contents), and practicality (narrow profile fits a corridor, adjustable shelves adapt to trophy sizes). The construction uses rebate joints for the glass panel and standard butt joints for the carcass, all achievable in a school workshop. [8]

(e) Full solution — construction details [12 marks]

The solution is drawn in exploded isometric projection.

• Carcass: 1200 mm tall x 500 mm wide x 300 mm deep, constructed from 18 mm oak-veneered MDF. Top, bottom, and two side panels are joined with biscuit joints or rebate joints, reinforced with PVA glue and panel pins.
• Glass door: A 6 mm toughened glass panel (1160 mm x 460 mm) sits in a 6 mm x 10 mm rebate cut along the inner front edge of each side panel, top, and bottom. A brass piano hinge (full length of one side) provides continuous support along the door edge.
• Lock: A small cam lock (barrel type) is fitted through a 19 mm hole drilled in the door-side panel at mid-height. The lock tongue engages with a keep plate screwed to the door.
• Shelves: Three shelves of 18 mm oak-veneered MDF (460 mm x 280 mm) rest on chrome-plated steel shelf support pins (5 mm diameter) inserted into a column of pre-drilled holes (spaced 32 mm apart) on each side panel interior. The 32 mm grid allows fine adjustment of shelf heights.
• Medal rail: A 460 mm brass rod (6 mm diameter) mounted horizontally on two small brackets at the top interior of the case, with six small brass S-hooks for hanging medals.
• Back panel: 6 mm MDF, pinned and glued into a rebate in the rear edge of the carcass.
• Wall mounting: French cleat system (two 450 mm bevelled strips, one on the wall, one on the case back).

(f) Materials [4 marks]

1. Oak-veneered MDF (18 mm) for the case body. Oak-veneered MDF combines the attractive appearance of real oak with the dimensional stability and smooth machinability of MDF. It will not warp or twist like solid timber, which is important for a large case where panel flatness ensures the glass door closes flush. It machines cleanly on a table saw and router, and the veneer edges can be finished with iron-on edging tape. [2]
2. Toughened glass (6 mm) for the front panel. Toughened glass is four to five times stronger than standard float glass of the same thickness. If broken (by an accidental impact in a busy corridor), it shatters into small, blunt granules rather than sharp shards, making it significantly safer. It is fully transparent for maximum display visibility and resists scratching better than acrylic. [2]

(g) Manufacturing the side panel [6 marks]

1. Mark out: Mark the panel dimensions (1200 mm x 300 mm) on an 18 mm oak-veneered MDF sheet using a pencil, steel rule, and try square. Mark the positions of shelf support holes along the inner face (two columns, 50 mm from front and back edges, holes at 32 mm intervals). [1]
2. Cut to size: Cut the panel using a table saw or circular saw with a fine-toothed blade to avoid chipping the veneer. Support the offcut to prevent breakout at the end of the cut. [1]
3. Rout glass rebate: Using a router with a rebate cutter, form a rebate (6 mm wide x 10 mm deep) along the inner front edge to receive the glass door panel. [1]
4. Drill shelf support holes: Drill a series of evenly spaced 5 mm holes along the inside face for the adjustable shelf support pins, using a pillar drill with a depth stop set to 10 mm and a spacing jig (a strip of MDF with pre-drilled holes at 32 mm intervals) clamped to the panel to ensure uniform spacing. [1]
5. Apply edge banding: Apply iron-on oak veneer edging tape to all exposed cut edges using a household iron set to medium heat. Trim the excess tape flush with the panel faces using a sharp craft knife or edge trimmer. [1]
6. Sand and finish: Sand all surfaces smooth with 180-grit glasspaper. Apply two coats of clear satin lacquer spray, sanding lightly with 240-grit between coats, to seal and protect the veneer. [1]

(a) Four functional points [4 marks]

1. No sharp edges or corners — Young children (aged 5-7) often move energetically and may bump into furniture. All edges and corners of the bookshelf must be rounded to at least a 10-15 mm radius to prevent cuts and bruises. This is a fundamental safety requirement for any furniture in a primary school setting. [1]
2. Stability against tipping — A child may lean against or pull on the bookshelf while reaching for a book. The unit must be heavy enough at the base, wide enough in footprint, or anchored to the wall so it cannot topple forward. A weighted base or a wide, low profile helps keep the centre of gravity stable. [1]
3. Forward-facing cover display — Children aged 5-7 are typically pre-readers or early readers who select books by their cover illustration rather than a spine title. The shelf must angle books so the full front cover faces outward, not just the narrow spine edge as in an adult bookcase. [1]
4. Height accessible to a five-year-old — The top shelf must be reachable by the smallest users (approximately 900-1000 mm standing height for a five-year-old). A maximum overall height of 900 mm ensures even the top tier can be reached without standing on tiptoe or climbing, which would be a safety hazard. [1]

(b) Two themed shapes [4 marks]

Shape 1 — House shape: The bookshelf silhouette has a rectangular body below and a pitched triangular roof section at the top, mimicking a simple house. Book troughs are set into the front face like windows, with the top trough sitting inside the triangular roof peak. This shape is universally recognised by young children and creates a cosy, inviting association with reading. The symmetrical geometry uses straight cuts that are simple to produce. [2]

Shape 2 — Tree shape: Two wide side panels are cut in the silhouette of a tree trunk that branches outward at the top. Shelves are set between the branches at different heights, so the books appear to be nestled among the tree limbs. This organic shape is appealing to children but requires complex curved cuts (coping saw or bandsaw) for the branch profiles, and the tapering width means shelves at different heights have different capacities. [2]

(c) Three design ideas [12 marks]

Idea 1 — House-shaped front panel with tiered troughs: Two side panels are cut from 18 mm plywood in a house profile (rectangular base + triangular pitched roof, total height 900 mm, width 700 mm). Three forward-facing book troughs are set at heights of 200 mm, 450 mm, and 650 mm from the floor. Each trough is a plywood base (250 mm deep) with a 50 mm front lip that supports books at a 10-degree backward angle so covers face outward. The triangular roof peak houses the top trough. A rear panel ties the structure together. Approximately 15 picture books can be displayed with covers visible. [4]

Idea 2 — Tree-trunk bookshelf with branch shelves: Side panels are cut in a tree trunk profile that widens and branches at the top. Irregularly spaced branch-shaped shelf brackets support four narrow shelves at different heights. The unit tapers upward, giving a natural appearance. The curved branch profiles require coping saw or bandsaw work and careful shaping. The irregular spacing makes the unit visually interesting but limits the number of books at the narrower upper levels. [4]

Idea 3 — Castle-shaped shelf with tower sections: Two tower sections at each side (each approximately 900 mm tall x 200 mm wide) are connected by a bridge shelf at the top. Books are stored in open arched alcoves cut into each tower. The castle theme appeals to children who enjoy fairy tales and imaginative play. The arched openings require careful marking out and curved cutting, and the twin-tower design has a larger footprint than the other ideas. [4]

(d) Evaluation and justification [8 marks]

Idea 1 (House shape) — Strengths: universally recognised by young children; symmetrical structure is inherently stable with a wide base; flat-panel construction uses straight cuts and housing joints achievable in a school workshop; three tiers accommodate approximately 15 forward-facing books. Weaknesses: the house shape, while familiar, is less visually dramatic than a tree or castle.

Idea 2 (Tree trunk) — Strengths: organic shape is visually appealing; irregularly spaced shelves add interest. Weaknesses: complex curved cuts for the branch profiles; uneven shelf widths limit storage; the narrowing upper section may feel unstable.

Idea 3 (Castle) — Strengths: imaginative theme; arched alcoves are visually striking. Weaknesses: arched cuts are difficult; twin towers create a large footprint; the bridge shelf at the top is above a five-year-old's reach.

Chosen idea: Idea 1. The house shape is the strongest choice because it uses straight cuts achievable in a school workshop, has an inherently stable wide-base profile, and maximises forward-facing book display within the 900 mm height limit. The pitched roof silhouette is immediately engaging for young children. [8]

(e) Full solution — construction details [12 marks]

The solution is drawn as a front elevation and side cross-section.

• Overall dimensions: 900 mm tall (to the roof peak), 700 mm wide, 300 mm deep.
• Side panels: Two pieces of 18 mm birch plywood cut in a house profile — rectangular base 700 mm tall, with a triangular roof rising to 900 mm at the centre apex. Three housing joints (6 mm deep, 12 mm wide) are routed into the inner face of each side panel at heights of 200 mm, 450 mm, and 650 mm to receive the trough bases.
• Book troughs: Three troughs made from 12 mm birch plywood bases (each 250 mm deep, extending the full 664 mm between the side panels). Each trough is angled back at 10 degrees using a wedge-shaped spacer. A 50 mm pine front lip is glued and pinned to the front edge of each trough base to hold books upright.
• Rear panel: A single sheet of 6 mm birch plywood (900 mm x 700 mm) cut to match the house profile, glued and pinned into a 5 mm rebate along the rear edge of each side panel. This panel braces the unit and keeps books from sliding through to the back.
• Safety: All outer corners are rounded to a 15 mm radius using a coping saw and spokeshave. All edges are sanded smooth. Non-toxic, water-based paint is applied in bright colours.

(f) Materials [4 marks]

1. Birch plywood (18 mm) for the side panels and trough bases. Birch plywood is strong, smooth, and free from splinters, making it safe for children's furniture. It takes water-based paint evenly, allowing bright colours that appeal to young children. The cross-laminated construction resists warping in the variable temperature and humidity of a school classroom. Birch plywood meets EN 71 toy safety standards for surface finish. [2]
2. Pine softwood (50 mm x 12 mm) for the trough front lips. Pine is lightweight (reducing the overall weight of the unit so it can be repositioned in the reading corner), easy to round over with a plane or router for safety, and inexpensive for the lengths required. It is soft enough to round all edges smoothly but firm enough to hold books upright without flexing. [2]

(g) Manufacturing one side panel [6 marks]

1. Template transfer: Make a full-size cardboard template of the house profile (900 mm tall at the peak, base width 700 mm, roof angle approximately 45 degrees). Place the template on an 18 mm birch plywood sheet (900 mm x 350 mm minimum) and trace the outline with a pencil. [1]
2. Cut straight edges: Cut the straight base and vertical sides using a tenon saw. Cut the two angled roof lines using a panel saw, keeping to the waste side. [1]
3. Cut housing joints: Mark the positions of three trough housings on the inner face using a try square and marking gauge (each 6 mm deep, 12 mm wide). Cut each housing using a router with a straight-cutter bit and guide fence, set to the correct depth. [1]
4. Round corners: Round all outer corners to a 15 mm radius using a coping saw to remove the bulk, then smooth with a spokeshave and sandpaper. This eliminates sharp points that could injure a child. [1]
5. Sand: Sand all surfaces to 240-grit, paying particular attention to the routed housing edges. [1]
6. Paint: Apply two coats of non-toxic, water-based paint in a bright colour (such as primary red, blue, or yellow), allowing full drying between coats. Non-toxic paint is mandatory for furniture used by children who may put their hands in their mouths after touching surfaces. [1]