Design & Technology 0445 | Paper 4 Mock 01 | Graphic Products
Question 1 Report
A furniture company produces flat-pack wooden bookshelves. The company currently manufactures 50 bookshelves per week using batch production. Each shelf panel is cut from MDF sheet using a CNC router.
(a) Explain what is meant by batch production. [2]
(b) Give two advantages of using a CNC router rather than a hand-held router to cut the shelf panels. [2]
(a) Batch production explained:
- Batch production involves manufacturing a set quantity of identical products (a batch of 50 bookshelves in this case) as a group before the equipment and tooling may be reconfigured for the next batch. [1]
- Each batch can be of a different specification (e.g. different shelf dimensions, finishes, or configurations), and there is typically downtime between batches for changeover, resetting the CNC program, and changing cutting tools if needed. [1]
(b) Two advantages of using a CNC router over a hand-held router:
- The CNC router cuts every shelf panel to exactly the same dimensions with very high accuracy and repeatability, ensuring all panels in the flat-pack are interchangeable and assemble correctly. [1]
- The CNC router can operate continuously without operator fatigue, producing panels faster than manual routing. It also cuts complex jointing details (e.g. housing joints, cam lock holes) automatically from the stored CAD data, eliminating manual measurement errors. [1]
Answer Details
(a) Batch production explained:
- Batch production involves manufacturing a set quantity of identical products (a batch of 50 bookshelves in this case) as a group before the equipment and tooling may be reconfigured for the next batch. [1]
- Each batch can be of a different specification (e.g. different shelf dimensions, finishes, or configurations), and there is typically downtime between batches for changeover, resetting the CNC program, and changing cutting tools if needed. [1]
(b) Two advantages of using a CNC router over a hand-held router:
- The CNC router cuts every shelf panel to exactly the same dimensions with very high accuracy and repeatability, ensuring all panels in the flat-pack are interchangeable and assemble correctly. [1]
- The CNC router can operate continuously without operator fatigue, producing panels faster than manual routing. It also cuts complex jointing details (e.g. housing joints, cam lock holes) automatically from the stored CAD data, eliminating manual measurement errors. [1]
Question 2 Report
Fig 26 shows a schematic of the mechanism layout for a mechanical toy. Turning a handle on the side makes a figure wave its arm up and down while simultaneously rotating on a circular turntable. The mechanism inside the toy must convert the single rotary input from the handle into two different output movements.
(a) Name a mechanism that could convert the rotary motion of the handle into the up-and-down motion of the figure's arm. [1]
(b) Explain how this mechanism works to produce the up-and-down arm movement. [2]
(c) The handle shaft must transmit rotation at 90 degrees to drive the horizontal turntable. Name a suitable gear type that can transmit rotary motion through a 90-degree angle. [1]
(d) The gear on the handle shaft has 12 teeth and the gear on the turntable shaft has 36 teeth. Calculate the gear ratio. Show your working. [1]
(e) State how many complete turns of the handle are needed for one complete rotation of the turntable. [1]
(a) A cam and follower mechanism converts the rotary motion of the handle into the up-and-down motion of the figure's arm. [1] This is the standard mechanism for producing controlled reciprocating or oscillating output from a rotary input, and it is widely used in toys, engines, and automated machinery.
(b) A cam is a specially shaped disc (or lobe) fixed to the rotating handle shaft. As the handle turns, the cam rotates with it. The cam profile has a varying radius from its centre: some portions bulge outward (the "rise") while others sit closer to the centre (the "fall"). [1] A follower, which is a rod or lever connected to the figure's arm, rests against the cam surface. As the cam rotates, the changing radius pushes the follower upward when the high-radius lobe passes underneath it, then allows the follower to drop back down (under gravity or spring return) as the low-radius portion comes around. [1] This continuous rotation produces the repetitive waving motion of the arm.
(c) Bevel gears transmit rotary motion through a 90-degree angle. [1] A pair of bevel gears has cone-shaped teeth cut along angled faces, and the two gear shafts meet at right angles. When one bevel gear turns, its angled teeth mesh with the partner gear and redirect the rotation by 90 degrees, making them ideal for driving the horizontal turntable from the vertical handle shaft.
(d) The gear ratio is calculated by dividing the number of teeth on the driven gear by the number of teeth on the driver gear:
\[ \text{Gear ratio} = \frac{\text{Teeth on driven gear}}{\text{Teeth on driver gear}} = \frac{36}{12} = 3 : 1 \]
The turntable gear is three times larger than the handle gear. [1]
(e) 3 complete turns of the handle are needed for one full rotation of the turntable. [1] Because the gear ratio is 3:1, the driven gear (turntable) turns three times slower than the driver gear (handle). For every three rotations of the smaller 12-tooth gear, the larger 36-tooth gear completes exactly one rotation. This speed reduction also means the torque at the turntable is three times greater than the torque applied at the handle, though speed is sacrificed.
Answer Details
(a) A cam and follower mechanism converts the rotary motion of the handle into the up-and-down motion of the figure's arm. [1] This is the standard mechanism for producing controlled reciprocating or oscillating output from a rotary input, and it is widely used in toys, engines, and automated machinery.
(b) A cam is a specially shaped disc (or lobe) fixed to the rotating handle shaft. As the handle turns, the cam rotates with it. The cam profile has a varying radius from its centre: some portions bulge outward (the "rise") while others sit closer to the centre (the "fall"). [1] A follower, which is a rod or lever connected to the figure's arm, rests against the cam surface. As the cam rotates, the changing radius pushes the follower upward when the high-radius lobe passes underneath it, then allows the follower to drop back down (under gravity or spring return) as the low-radius portion comes around. [1] This continuous rotation produces the repetitive waving motion of the arm.
(c) Bevel gears transmit rotary motion through a 90-degree angle. [1] A pair of bevel gears has cone-shaped teeth cut along angled faces, and the two gear shafts meet at right angles. When one bevel gear turns, its angled teeth mesh with the partner gear and redirect the rotation by 90 degrees, making them ideal for driving the horizontal turntable from the vertical handle shaft.
(d) The gear ratio is calculated by dividing the number of teeth on the driven gear by the number of teeth on the driver gear:
\[ \text{Gear ratio} = \frac{\text{Teeth on driven gear}}{\text{Teeth on driver gear}} = \frac{36}{12} = 3 : 1 \]
The turntable gear is three times larger than the handle gear. [1]
(e) 3 complete turns of the handle are needed for one full rotation of the turntable. [1] Because the gear ratio is 3:1, the driven gear (turntable) turns three times slower than the driver gear (handle). For every three rotations of the smaller 12-tooth gear, the larger 36-tooth gear completes exactly one rotation. This speed reduction also means the torque at the turntable is three times greater than the torque applied at the handle, though speed is sacrificed.
Question 3 Report
Fig 10 shows a portable workbench designed for use on building sites.
(a) The frame corners are joined using MIG welding.
(i) Describe the MIG welding process used to join the steel tubes at each corner of the frame. [4]
(ii) Give two advantages of using MIG welding over brazing for joining these steel tubes. [2]
(b) The clamping system uses a first-class lever.
(i) With the aid of a labelled sketch, explain how the lever mechanism provides a mechanical advantage when clamping a workpiece. [4]
(ii) Explain why increasing the length of the lever arm would make clamping easier for the user. [2]
(c) The folding version requires a pivot joint at each leg.
(i) Name and describe a suitable permanent mechanical joint that allows each leg to rotate against the frame. [2]
(ii) Sketch a locking device that holds each leg rigidly in the open position during use. [3]
(d) The steel tubes need protection from corrosion in outdoor conditions.
(i) Give two methods of protecting the steel frame from corrosion. [2]
(ii) For one method you identified in (d)(i), explain why it is particularly suitable for a workbench used on building sites. [2]
(e) The manufacturer considers using aluminium alloy tube instead of steel for the main frame.
Give two advantages and two disadvantages of aluminium alloy compared to steel for this product. [4]
(a)(i) Description of MIG welding for joining the steel tubes at each corner: [4]
- MIG (Metal Inert Gas) welding uses a continuously fed consumable wire electrode from a spool. The wire simultaneously serves as the filler material, so no separate filler rod is needed. [1]
- An electric arc forms between the tip of the wire and the mild steel workpiece, generating intense heat that melts both the wire and the parent metal to create a molten weld pool where the tube surfaces fuse. [1]
- An inert shielding gas (argon or an argon/CO2 mixture) is fed through the torch nozzle. This gas envelope surrounds the arc and weld pool, preventing atmospheric oxygen and nitrogen from contaminating the molten metal, which would otherwise cause porosity and weak joints. [1]
- The welder guides the torch steadily along the joint line at a controlled speed. As the torch advances, the weld pool solidifies behind it, leaving a continuous bead that permanently fuses the two tubes at the corner. [1]
(a)(ii) Two advantages of MIG welding over brazing for these steel tubes: [2]
- MIG welding is faster with a higher deposition rate than brazing, making it more efficient for joining multiple corners on a production workbench. [1]
- MIG welding produces a stronger joint because the parent metals are fused together into one continuous piece, whereas brazing relies on a filler metal with a lower melting point that bonds by capillary action without melting the parent steel. [1]
(b)(i) The clamping system uses a first-class lever, where the fulcrum (pivot) is positioned between the effort (applied by the user's hand) and the load (the clamping force on the workpiece).
The sketch shows: the fulcrum/pivot positioned between the effort and the load [1]; effort applied by the user's hand at one end of the lever arm [1]; the clamping load acting on the jaw and workpiece at the other end [1]. Because the effort arm (fulcrum to hand) is longer than the load arm (fulcrum to jaw), the force applied to the workpiece is multiplied. This is the principle of mechanical advantage: a small effort over a large distance produces a large force over a small distance. [1]
(b)(ii) Increasing the length of the lever arm increases the distance from the point where the user applies effort to the fulcrum. [1] Since mechanical advantage equals the effort arm length divided by the load arm length (\( MA = \frac{\text{effort arm}}{\text{load arm}} \)), a longer effort arm means a greater mechanical advantage. The user can therefore apply a larger clamping force to the workpiece for the same physical effort, making clamping easier. [1]
(c)(i) A suitable permanent mechanical joint is a bolt (or clevis pin) acting as a pivot. A bolt passes through aligned holes in a bracket welded to the frame and a lug attached to the leg. [1] This allows the leg to rotate freely about the bolt axis while keeping the leg permanently attached to the frame. The bolt is secured with a nut or split pin to prevent it from working loose. [1]
(c)(ii) A locking device to hold each leg rigidly in the open position:
The sketch shows: a toggle clamp / over-centre latch mechanism that engages when the leg reaches its fully open position [1]; a stop plate or shoulder on the frame that prevents the leg from rotating past 90 degrees [1]; both the locked position (latch engaged, leg rigid) and the released position (latch lifted, leg free to fold) are indicated [1].
(d)(i) Two methods of protecting the steel frame from corrosion: [2]
- Galvanising (hot-dip zinc coating) [1]
- Powder coating (or paint / spray finish) [1]
(d)(ii) Galvanising is particularly suitable for a workbench used on building sites because the zinc layer provides sacrificial protection. [1] Even if the surface is scratched, chipped, or dented during rough handling on site, the zinc corrodes preferentially to the steel underneath (because zinc is more reactive), continuing to protect the exposed steel from rusting. This self-healing protection is critical for equipment subjected to heavy wear. [1]
(e) Advantages and disadvantages of aluminium alloy compared to steel: [4]
| Advantages | Disadvantages |
|---|---|
| Aluminium alloy is lighter (lower density, approximately one-third the density of steel), making the workbench easier to carry to different locations on site. [1] | Aluminium alloy is more expensive than mild steel, increasing the manufacturing cost of the product. [1] |
| Aluminium alloy has good natural corrosion resistance due to its self-forming oxide layer, reducing or eliminating the need for protective coatings like galvanising or painting. [1] | Aluminium alloy has a lower stiffness (lower Young's modulus), so the frame may flex more under heavy clamping loads or when supporting heavy workpieces, reducing stability. [1] |
Answer Details
(a)(i) Description of MIG welding for joining the steel tubes at each corner: [4]
- MIG (Metal Inert Gas) welding uses a continuously fed consumable wire electrode from a spool. The wire simultaneously serves as the filler material, so no separate filler rod is needed. [1]
- An electric arc forms between the tip of the wire and the mild steel workpiece, generating intense heat that melts both the wire and the parent metal to create a molten weld pool where the tube surfaces fuse. [1]
- An inert shielding gas (argon or an argon/CO2 mixture) is fed through the torch nozzle. This gas envelope surrounds the arc and weld pool, preventing atmospheric oxygen and nitrogen from contaminating the molten metal, which would otherwise cause porosity and weak joints. [1]
- The welder guides the torch steadily along the joint line at a controlled speed. As the torch advances, the weld pool solidifies behind it, leaving a continuous bead that permanently fuses the two tubes at the corner. [1]
(a)(ii) Two advantages of MIG welding over brazing for these steel tubes: [2]
- MIG welding is faster with a higher deposition rate than brazing, making it more efficient for joining multiple corners on a production workbench. [1]
- MIG welding produces a stronger joint because the parent metals are fused together into one continuous piece, whereas brazing relies on a filler metal with a lower melting point that bonds by capillary action without melting the parent steel. [1]
(b)(i) The clamping system uses a first-class lever, where the fulcrum (pivot) is positioned between the effort (applied by the user's hand) and the load (the clamping force on the workpiece).
The sketch shows: the fulcrum/pivot positioned between the effort and the load [1]; effort applied by the user's hand at one end of the lever arm [1]; the clamping load acting on the jaw and workpiece at the other end [1]. Because the effort arm (fulcrum to hand) is longer than the load arm (fulcrum to jaw), the force applied to the workpiece is multiplied. This is the principle of mechanical advantage: a small effort over a large distance produces a large force over a small distance. [1]
(b)(ii) Increasing the length of the lever arm increases the distance from the point where the user applies effort to the fulcrum. [1] Since mechanical advantage equals the effort arm length divided by the load arm length (\( MA = \frac{\text{effort arm}}{\text{load arm}} \)), a longer effort arm means a greater mechanical advantage. The user can therefore apply a larger clamping force to the workpiece for the same physical effort, making clamping easier. [1]
(c)(i) A suitable permanent mechanical joint is a bolt (or clevis pin) acting as a pivot. A bolt passes through aligned holes in a bracket welded to the frame and a lug attached to the leg. [1] This allows the leg to rotate freely about the bolt axis while keeping the leg permanently attached to the frame. The bolt is secured with a nut or split pin to prevent it from working loose. [1]
(c)(ii) A locking device to hold each leg rigidly in the open position:
The sketch shows: a toggle clamp / over-centre latch mechanism that engages when the leg reaches its fully open position [1]; a stop plate or shoulder on the frame that prevents the leg from rotating past 90 degrees [1]; both the locked position (latch engaged, leg rigid) and the released position (latch lifted, leg free to fold) are indicated [1].
(d)(i) Two methods of protecting the steel frame from corrosion: [2]
- Galvanising (hot-dip zinc coating) [1]
- Powder coating (or paint / spray finish) [1]
(d)(ii) Galvanising is particularly suitable for a workbench used on building sites because the zinc layer provides sacrificial protection. [1] Even if the surface is scratched, chipped, or dented during rough handling on site, the zinc corrodes preferentially to the steel underneath (because zinc is more reactive), continuing to protect the exposed steel from rusting. This self-healing protection is critical for equipment subjected to heavy wear. [1]
(e) Advantages and disadvantages of aluminium alloy compared to steel: [4]
| Advantages | Disadvantages |
|---|---|
| Aluminium alloy is lighter (lower density, approximately one-third the density of steel), making the workbench easier to carry to different locations on site. [1] | Aluminium alloy is more expensive than mild steel, increasing the manufacturing cost of the product. [1] |
| Aluminium alloy has good natural corrosion resistance due to its self-forming oxide layer, reducing or eliminating the need for protective coatings like galvanising or painting. [1] | Aluminium alloy has a lower stiffness (lower Young's modulus), so the frame may flex more under heavy clamping loads or when supporting heavy workpieces, reducing stability. [1] |
Question 4 Report
Fig 17 shows a workshop lathe used for turning metal components.
(a) (i) State two safety features that should be fitted to the lathe. [2]
(ii) Explain why an emergency stop button is an important safety feature on a lathe. [2]
[Total: 4 marks]
(a)(i) Two safety features that should be fitted to a lathe:
- Emergency stop button (mushroom-head stop) - a large, clearly visible red button that immediately cuts power to the motor. [1]
- Chuck guard (protective screen) - a transparent shield that encloses the rotating chuck and workpiece area, preventing the operator from accidentally contacting the spinning parts and shielding against flying swarf. [1]
(Other acceptable answers: no-volt release switch that prevents the lathe restarting automatically after a power cut; interlocked chuck guard that stops the motor when the guard is opened.)
(a)(ii) The emergency stop button provides an immediate way to shut down the lathe in a dangerous situation. [1] If the workpiece comes loose from the chuck, material wraps around the spindle, or the operator's clothing or hair gets caught in the rotating parts, the emergency stop can be hit instantly - even with an elbow or body - without needing to reach for the normal controls. This rapid shutdown can prevent a minor incident from becoming a serious injury. [1]
Answer Details
(a)(i) Two safety features that should be fitted to a lathe:
- Emergency stop button (mushroom-head stop) - a large, clearly visible red button that immediately cuts power to the motor. [1]
- Chuck guard (protective screen) - a transparent shield that encloses the rotating chuck and workpiece area, preventing the operator from accidentally contacting the spinning parts and shielding against flying swarf. [1]
(Other acceptable answers: no-volt release switch that prevents the lathe restarting automatically after a power cut; interlocked chuck guard that stops the motor when the guard is opened.)
(a)(ii) The emergency stop button provides an immediate way to shut down the lathe in a dangerous situation. [1] If the workpiece comes loose from the chuck, material wraps around the spindle, or the operator's clothing or hair gets caught in the rotating parts, the emergency stop can be hit instantly - even with an elbow or body - without needing to reach for the normal controls. This rapid shutdown can prevent a minor incident from becoming a serious injury. [1]
Question 5 Report
A student is designing a model railway crossing signal. The circuit uses several electronic components including a capacitor and a light emitting diode (LED). The LED is connected in series with a resistor to indicate when a train is approaching.
(a) State the function of a capacitor in an electronic circuit. [1]
(b) Explain why a resistor must be connected in series with an LED. [1]
(a) A capacitor stores electrical charge (energy). [1]
A capacitor consists of two conductive plates separated by an insulating layer (dielectric). When a voltage is applied, electrons accumulate on one plate and are depleted from the other, creating an electric field that stores energy. This stored charge can later be released back into the circuit. In electronic timing circuits such as a 555 timer, the charge and discharge rate of a capacitor determines the output timing. In power supply circuits, capacitors smooth out voltage fluctuations.
(b) A resistor must be connected in series with an LED to limit the current flowing through it, preventing damage. [1]
An LED is a semiconductor device with a very low forward resistance once it begins conducting. Without a series resistor, the current drawn from the power supply would be far higher than the LED's maximum rated current (typically 20 mA for a standard indicator LED). This excessive current would overheat the junction inside the LED, destroying it almost instantly. The series resistor creates a controlled voltage drop that restricts the current to a safe level. The required resistance is calculated using Ohm's law: \( R = \frac{V_{\text{supply}} - V_{\text{LED}}}{I_{\text{LED}}} \).
Answer Details
(a) A capacitor stores electrical charge (energy). [1]
A capacitor consists of two conductive plates separated by an insulating layer (dielectric). When a voltage is applied, electrons accumulate on one plate and are depleted from the other, creating an electric field that stores energy. This stored charge can later be released back into the circuit. In electronic timing circuits such as a 555 timer, the charge and discharge rate of a capacitor determines the output timing. In power supply circuits, capacitors smooth out voltage fluctuations.
(b) A resistor must be connected in series with an LED to limit the current flowing through it, preventing damage. [1]
An LED is a semiconductor device with a very low forward resistance once it begins conducting. Without a series resistor, the current drawn from the power supply would be far higher than the LED's maximum rated current (typically 20 mA for a standard indicator LED). This excessive current would overheat the junction inside the LED, destroying it almost instantly. The series resistor creates a controlled voltage drop that restricts the current to a safe level. The required resistance is calculated using Ohm's law: \( R = \frac{V_{\text{supply}} - V_{\text{LED}}}{I_{\text{LED}}} \).
Question 6 Report
Fig 21 shows two spur gears meshing together in a hand-operated food mixer. The larger gear is turned by the handle and drives the smaller gear which rotates the mixer beaters.
(a) Name the type of gears shown in Fig 21. [1]
(b) The driver gear rotates clockwise as shown by the arrow. State the direction of rotation of the driven gear. [1]
(a) The gears shown in the figure are spur gears. [1] Spur gears have straight-cut teeth arranged around the circumference of a cylindrical wheel. They are the simplest and most common type of gear, used to transmit rotary motion and force between two parallel shafts. The teeth mesh along a line of contact parallel to the shaft axis, which is why they are called "spur" gears.
(b) The driven gear rotates anti-clockwise (counter-clockwise). [1] When two meshing spur gears are in contact, their teeth interlock at the point where the two circles meet. As the driver gear turns clockwise, its teeth push against the teeth of the driven gear at the meshing point, forcing the driven gear to rotate in the opposite direction. This reversal of direction is a fundamental property of all externally meshing gear pairs: the driving teeth on one gear push the driven teeth on the other gear in the opposite rotational sense.
Answer Details
(a) The gears shown in the figure are spur gears. [1] Spur gears have straight-cut teeth arranged around the circumference of a cylindrical wheel. They are the simplest and most common type of gear, used to transmit rotary motion and force between two parallel shafts. The teeth mesh along a line of contact parallel to the shaft axis, which is why they are called "spur" gears.
(b) The driven gear rotates anti-clockwise (counter-clockwise). [1] When two meshing spur gears are in contact, their teeth interlock at the point where the two circles meet. As the driver gear turns clockwise, its teeth push against the teeth of the driven gear at the meshing point, forcing the driven gear to rotate in the opposite direction. This reversal of direction is a fundamental property of all externally meshing gear pairs: the driving teeth on one gear push the driven teeth on the other gear in the opposite rotational sense.
Question 7 Report
Fig 15 shows a spur gear train used in a hand-powered drill. Gear A is the driver gear and gear B is the driven gear.
(a) (i) Calculate the gear ratio of the gear train shown in Fig 15. Show your working. [2]
(ii) The driver gear A rotates at 80 rpm. Calculate the speed of the driven gear B. Show your working. [2]
[Total: 4 marks]
(a)(i) The gear ratio is calculated by dividing the number of teeth on the driven gear by the number of teeth on the driver gear:
\[ \text{Gear ratio} = \frac{\text{Driven teeth}}{\text{Driver teeth}} = \frac{48}{12} = 4 : 1 \]
[1] for the correct formula or method, [1] for the correct answer. The driven gear B has four times as many teeth as the driver gear A, so it turns four times slower.
(a)(ii) The speed of gear B:
\[ \text{Speed of B} = \frac{\text{Speed of A}}{\text{Gear ratio}} = \frac{80\,\text{rpm}}{4} = 20\,\text{rpm} \]
[1] for the correct method, [1] for the correct answer. For every four turns of the small driver gear A, the large driven gear B completes one turn. This speed reduction is accompanied by a fourfold increase in torque at the output, which provides greater drilling force at a controlled speed for the hand drill.
Answer Details
(a)(i) The gear ratio is calculated by dividing the number of teeth on the driven gear by the number of teeth on the driver gear:
\[ \text{Gear ratio} = \frac{\text{Driven teeth}}{\text{Driver teeth}} = \frac{48}{12} = 4 : 1 \]
[1] for the correct formula or method, [1] for the correct answer. The driven gear B has four times as many teeth as the driver gear A, so it turns four times slower.
(a)(ii) The speed of gear B:
\[ \text{Speed of B} = \frac{\text{Speed of A}}{\text{Gear ratio}} = \frac{80\,\text{rpm}}{4} = 20\,\text{rpm} \]
[1] for the correct method, [1] for the correct answer. For every four turns of the small driver gear A, the large driven gear B completes one turn. This speed reduction is accompanied by a fourfold increase in torque at the output, which provides greater drilling force at a controlled speed for the hand drill.
Question 8 Report
Fig 10 shows a pillar drill press used in a school design and technology workshop for drilling holes in metal and plastic workpieces.
(a) Calculate the overall gear ratio of the compound spur gear train from the motor shaft to the drill spindle. Show your working. [3]
(b)(i) Calculate the output speed of the drill spindle in rpm. Show your working. [2]
(b)(ii) Give one advantage of using a compound gear train with intermediate spur gears rather than a single pair of gears to achieve this speed reduction. [1]
(c)(i) Name the type of motion produced by the electric motor. [1]
(c)(ii) Name the type of motion produced at the drill chuck when the operator pushes the lever handle downward. [1]
(d)(i) Calculate the mechanical advantage of the lever handle. Show your working. [2]
(d)(ii) Identify the class of lever used in this drill press mechanism. [1]
(d)(iii) Sketch the lever arrangement of the drill press handle showing the positions of the effort, load and fulcrum. Label each clearly. [2]
(e)(i) Sketch a pair of meshing spur gears. Show the direction of rotation of each gear using arrows. Label the driver gear and the driven gear. [3]
(e)(ii) Give one advantage of using spur gears over bevel gears when transmitting motion between parallel shafts. [1]
(f)(i) Name one type of gear that can transmit rotary motion between shafts arranged at right angles. [1]
(f)(ii) Give one practical application where this type of gear would be used. [1]
(g) Give two mechanical properties required of the return spring material used in the drill press mechanism. [2]
(h)(i) Explain why the depth stop is an important feature of the drill press mechanism. [2]
(h)(ii) Give two safety precautions the operator should follow when using the pillar drill press. [2]
[Total: 25 marks]
(a) The overall gear ratio of the compound spur gear train is found by multiplying the individual stage ratios:
\[ \text{Stage 1 ratio} = \frac{\text{Driven teeth}}{\text{Driver teeth}} = \frac{40}{20} = 2 : 1 \]
\[ \text{Stage 2 ratio} = \frac{60}{20} = 3 : 1 \]
\[ \text{Overall gear ratio} = 2 \times 3 = 6 : 1 \]
[1] for each stage ratio, [1] for the correct overall ratio. In a compound gear train, the output shaft of the first stage is mechanically linked (on the same shaft) to the input gear of the second stage, so the ratios multiply rather than add.
(b)(i) The output speed of the drill spindle:
\[ \text{Output speed} = \frac{\text{Input speed}}{\text{Overall gear ratio}} = \frac{2800\,\text{rpm}}{6} = 466.7\,\text{rpm} \]
[1] for the correct method, [1] for the correct answer (accept 467 rpm). The motor speed is divided by the overall ratio to give the spindle speed.
(b)(ii) A compound gear train achieves a large speed reduction in a compact space. [1] A single pair of spur gears with a 6:1 ratio would require the driven gear to be six times the diameter of the driver, making it impractically large for the drill's column housing. Splitting the reduction across two stages keeps all gears small.
(c)(i) The electric motor produces rotary motion. [1] The motor shaft spins continuously around its axis.
(c)(ii) When the operator pushes the lever handle downward, the drill chuck produces linear motion. [1] The chuck and drill bit travel in a straight line downward into the workpiece.
(d)(i) The mechanical advantage of the lever handle:
\[ \text{MA} = \frac{\text{Effort distance}}{\text{Load distance}} = \frac{250\,\text{mm}}{50\,\text{mm}} = 5 \]
[1] for the formula, [1] for the correct answer. The operator applies force at 250 mm from the pivot and the load acts at 50 mm, so the output force is five times the input force.
(d)(ii) The drill press uses a Class 2 lever. [1] The fulcrum is at the pivot where the handle mounts to the column, the load (drill resistance) acts at the pinion close to the fulcrum, and the effort (operator's hand) is applied at the far end of the handle. In a Class 2 lever, the load is always between the fulcrum and the effort.
(d)(iii) A sketch of the drill press lever arrangement:
[1] for the correct lever arrangement with load between fulcrum and effort, [1] for clear labels on all three elements.
(e)(i) Two meshing spur gears:
[1] for correct gear shapes with teeth, [1] for opposite rotation arrows (driver clockwise, driven anti-clockwise), [1] for correct labels. The teeth mesh at the point of contact, and the driver pushes the driven gear in the opposite rotational direction.
(e)(ii) Spur gears are simpler to manufacture and produce no axial thrust along the shaft. [1] When the shafts are already parallel, spur gears transmit motion efficiently without the complexity and cost of bevel gears, which are designed for shafts at an angle.
(f)(i) Bevel gears transmit rotary motion between shafts at right angles. [1] (Also acceptable: worm gear or mitre gear.)
(f)(ii) Bevel gears are used in a hand drill to change the direction of rotation by 90 degrees, allowing the drill bit to turn at right angles to the handle crank. [1] (Also acceptable: car differential, angle grinder, food mixer.)
(g) Two mechanical properties required of the return spring material:
- High elasticity (resilience): the spring must return to its original shape after being compressed or extended repeatedly, without taking a permanent set (plastic deformation). [1]
- High tensile strength: the spring must resist the repeated stress cycles of the drilling operation without fracturing or developing fatigue cracks. [1]
(Also acceptable: corrosion resistance, fatigue resistance, good hardness.)
(h)(i) The depth stop prevents the drill bit from travelling too far through the workpiece, which could damage the worktable surface, break the drill bit, or cause the workpiece to lift off the clamp. [1] It also allows consistent hole depths to be set when producing a batch of identical components, ensuring dimensional accuracy across repeated operations. [1]
(h)(ii) Two safety precautions:
- Always clamp the workpiece securely in a machine vice or with a G-clamp before drilling, to prevent it from spinning with the drill bit and striking the operator. [1]
- Wear safety goggles to protect the eyes from flying metal swarf and debris produced during drilling. [1]
(Also acceptable: tie back loose hair and remove loose clothing or jewellery; use the guard; select the correct drill speed for the material; remove the chuck key before starting the motor.)
Answer Details
(a) The overall gear ratio of the compound spur gear train is found by multiplying the individual stage ratios:
\[ \text{Stage 1 ratio} = \frac{\text{Driven teeth}}{\text{Driver teeth}} = \frac{40}{20} = 2 : 1 \]
\[ \text{Stage 2 ratio} = \frac{60}{20} = 3 : 1 \]
\[ \text{Overall gear ratio} = 2 \times 3 = 6 : 1 \]
[1] for each stage ratio, [1] for the correct overall ratio. In a compound gear train, the output shaft of the first stage is mechanically linked (on the same shaft) to the input gear of the second stage, so the ratios multiply rather than add.
(b)(i) The output speed of the drill spindle:
\[ \text{Output speed} = \frac{\text{Input speed}}{\text{Overall gear ratio}} = \frac{2800\,\text{rpm}}{6} = 466.7\,\text{rpm} \]
[1] for the correct method, [1] for the correct answer (accept 467 rpm). The motor speed is divided by the overall ratio to give the spindle speed.
(b)(ii) A compound gear train achieves a large speed reduction in a compact space. [1] A single pair of spur gears with a 6:1 ratio would require the driven gear to be six times the diameter of the driver, making it impractically large for the drill's column housing. Splitting the reduction across two stages keeps all gears small.
(c)(i) The electric motor produces rotary motion. [1] The motor shaft spins continuously around its axis.
(c)(ii) When the operator pushes the lever handle downward, the drill chuck produces linear motion. [1] The chuck and drill bit travel in a straight line downward into the workpiece.
(d)(i) The mechanical advantage of the lever handle:
\[ \text{MA} = \frac{\text{Effort distance}}{\text{Load distance}} = \frac{250\,\text{mm}}{50\,\text{mm}} = 5 \]
[1] for the formula, [1] for the correct answer. The operator applies force at 250 mm from the pivot and the load acts at 50 mm, so the output force is five times the input force.
(d)(ii) The drill press uses a Class 2 lever. [1] The fulcrum is at the pivot where the handle mounts to the column, the load (drill resistance) acts at the pinion close to the fulcrum, and the effort (operator's hand) is applied at the far end of the handle. In a Class 2 lever, the load is always between the fulcrum and the effort.
(d)(iii) A sketch of the drill press lever arrangement:
[1] for the correct lever arrangement with load between fulcrum and effort, [1] for clear labels on all three elements.
(e)(i) Two meshing spur gears:
[1] for correct gear shapes with teeth, [1] for opposite rotation arrows (driver clockwise, driven anti-clockwise), [1] for correct labels. The teeth mesh at the point of contact, and the driver pushes the driven gear in the opposite rotational direction.
(e)(ii) Spur gears are simpler to manufacture and produce no axial thrust along the shaft. [1] When the shafts are already parallel, spur gears transmit motion efficiently without the complexity and cost of bevel gears, which are designed for shafts at an angle.
(f)(i) Bevel gears transmit rotary motion between shafts at right angles. [1] (Also acceptable: worm gear or mitre gear.)
(f)(ii) Bevel gears are used in a hand drill to change the direction of rotation by 90 degrees, allowing the drill bit to turn at right angles to the handle crank. [1] (Also acceptable: car differential, angle grinder, food mixer.)
(g) Two mechanical properties required of the return spring material:
- High elasticity (resilience): the spring must return to its original shape after being compressed or extended repeatedly, without taking a permanent set (plastic deformation). [1]
- High tensile strength: the spring must resist the repeated stress cycles of the drilling operation without fracturing or developing fatigue cracks. [1]
(Also acceptable: corrosion resistance, fatigue resistance, good hardness.)
(h)(i) The depth stop prevents the drill bit from travelling too far through the workpiece, which could damage the worktable surface, break the drill bit, or cause the workpiece to lift off the clamp. [1] It also allows consistent hole depths to be set when producing a batch of identical components, ensuring dimensional accuracy across repeated operations. [1]
(h)(ii) Two safety precautions:
- Always clamp the workpiece securely in a machine vice or with a G-clamp before drilling, to prevent it from spinning with the drill bit and striking the operator. [1]
- Wear safety goggles to protect the eyes from flying metal swarf and debris produced during drilling. [1]
(Also acceptable: tie back loose hair and remove loose clothing or jewellery; use the guard; select the correct drill speed for the material; remove the chuck key before starting the motor.)
Question 9 Report
Fig 15 shows a wall-mounted room number sign used in a hotel. The sign is made from 5 mm white foamboard measuring 300 mm by 200 mm. The room number and hotel logo are cut from self-adhesive vinyl sheet and applied to the foamboard surface. The corners of the sign are rounded and the sign is fixed to the wall using double-sided adhesive pads on the back face.
(a) Name the machine used to cut the vinyl lettering and logo from the vinyl sheet. [1]
(b) Describe how the vinyl lettering is applied to the foamboard surface. [2]
[Total: 3 marks]
(a) The machine used to cut the vinyl lettering and logo:
Vinyl cutter (also called a plotter cutter or cutting plotter). [1] The machine uses a small, computer-controlled blade that follows a vector path generated from the digital design file. It cuts through the top vinyl layer but not through the backing paper beneath (known as kiss cutting).
(b) How the vinyl lettering is applied to the foamboard surface:
- The unwanted vinyl around the letters is peeled away (a process called weeding), leaving only the cut letters and logo on the backing paper. Transfer tape (a low-tack adhesive sheet) is then applied over the top surface of the letters to hold them in their correct relative positions. [1]
- The backing paper is peeled away from the underside, exposing the adhesive face of the vinyl. The letters are then positioned precisely on the foamboard surface and pressed down firmly using a squeegee or roller, working from the centre outward to remove air bubbles and ensure a strong, smooth bond. The transfer tape is then carefully peeled off, leaving the vinyl letters adhered to the foamboard. [1]
Answer Details
(a) The machine used to cut the vinyl lettering and logo:
Vinyl cutter (also called a plotter cutter or cutting plotter). [1] The machine uses a small, computer-controlled blade that follows a vector path generated from the digital design file. It cuts through the top vinyl layer but not through the backing paper beneath (known as kiss cutting).
(b) How the vinyl lettering is applied to the foamboard surface:
- The unwanted vinyl around the letters is peeled away (a process called weeding), leaving only the cut letters and logo on the backing paper. Transfer tape (a low-tack adhesive sheet) is then applied over the top surface of the letters to hold them in their correct relative positions. [1]
- The backing paper is peeled away from the underside, exposing the adhesive face of the vinyl. The letters are then positioned precisely on the foamboard surface and pressed down firmly using a squeegee or roller, working from the centre outward to remove air bubbles and ensure a strong, smooth bond. The transfer tape is then carefully peeled off, leaving the vinyl letters adhered to the foamboard. [1]
Question 10 Report
Fig 2 shows a student cutting a sheet of mounting board using a craft knife. The student is preparing pieces for a point-of-sale display model. The mounting board is placed on the workbench surface and the student is holding a plastic ruler against the board to guide the cut.
(a) State two safety precautions the student should follow when using the craft knife. [2]
[Total: 2 marks]
(a) Two safety precautions when using a craft knife:
- Always cut on a cutting mat placed on the workbench. [1] The cutting mat protects the bench surface from blade damage and, crucially, provides a non-slip surface that prevents the blade from skating off the material and into the user's hand. A hard bench surface can deflect the blade unpredictably.
- Use a metal safety ruler rather than a plastic ruler to guide the cut. [1] A craft knife blade can easily slice into a plastic ruler edge, causing the blade to ride up over the ruler and cut the user's fingers. A metal ruler has a hard edge that the blade cannot cut into, keeping the blade tracking along the intended cut line.
(Other acceptable answers: always cut away from the body; keep fingers behind the blade at all times; retract the blade when not in use.)
Answer Details
(a) Two safety precautions when using a craft knife:
- Always cut on a cutting mat placed on the workbench. [1] The cutting mat protects the bench surface from blade damage and, crucially, provides a non-slip surface that prevents the blade from skating off the material and into the user's hand. A hard bench surface can deflect the blade unpredictably.
- Use a metal safety ruler rather than a plastic ruler to guide the cut. [1] A craft knife blade can easily slice into a plastic ruler edge, causing the blade to ride up over the ruler and cut the user's fingers. A metal ruler has a hard edge that the blade cannot cut into, keeping the blade tracking along the intended cut line.
(Other acceptable answers: always cut away from the body; keep fingers behind the blade at all times; retract the blade when not in use.)
Question 11 Report
State the correct item of personal protective equipment (PPE) for each of the following workshop activities.
(a) Using a lathe to turn a metal bar. [1]
(b) Cutting wood on a circular saw. [1]
(c) Applying spray paint to a metal surface in a spray booth. [1]
[Total: 3 marks]
(a) When using a lathe to turn a metal bar, the correct PPE is safety goggles (eye protection). [1] Hot metal swarf is thrown off the workpiece at high speed during turning, and safety goggles prevent these sharp, hot fragments from reaching the operator's eyes. (Also acceptable: face shield.)
(b) When cutting wood on a circular saw, the correct PPE is ear defenders (ear protection). [1] Circular saws produce high noise levels that can cause permanent hearing damage with prolonged or repeated exposure. (Also acceptable: safety goggles, dust mask.)
(c) When applying spray paint in a spray booth, the correct PPE is a respirator or spray mask with an appropriate filter cartridge. [1] Spray painting atomises the paint into very fine droplets and releases solvent vapour, both of which can be inhaled deep into the lungs. A respirator with organic vapour and particulate filters prevents inhalation of both the paint mist and the solvent fumes. (Also acceptable: safety goggles to protect eyes from overspray.)
Answer Details
(a) When using a lathe to turn a metal bar, the correct PPE is safety goggles (eye protection). [1] Hot metal swarf is thrown off the workpiece at high speed during turning, and safety goggles prevent these sharp, hot fragments from reaching the operator's eyes. (Also acceptable: face shield.)
(b) When cutting wood on a circular saw, the correct PPE is ear defenders (ear protection). [1] Circular saws produce high noise levels that can cause permanent hearing damage with prolonged or repeated exposure. (Also acceptable: safety goggles, dust mask.)
(c) When applying spray paint in a spray booth, the correct PPE is a respirator or spray mask with an appropriate filter cartridge. [1] Spray painting atomises the paint into very fine droplets and releases solvent vapour, both of which can be inhaled deep into the lungs. A respirator with organic vapour and particulate filters prevents inhalation of both the paint mist and the solvent fumes. (Also acceptable: safety goggles to protect eyes from overspray.)
Question 12 Report
Fig 9 shows a desk organiser used in a design studio. The base is made from medium-density fibreboard (MDF) coated with melamine. The pen holder is a section of aluminium tube. The phone stand is bent from a single piece of clear acrylic sheet.
(a) State whether aluminium is a ferrous or non-ferrous metal. [1]
(b) Name the material classification of acrylic. [1]
(c) Give one property of MDF that makes it suitable for the base of the desk organiser. [1]
[Total: 3 marks]
(a) Aluminium is a non-ferrous metal. [1] Non-ferrous metals are those that do not contain iron as their primary element. Aluminium is lightweight, corrosion-resistant, and non-magnetic, all characteristic properties of non-ferrous metals.
(b) Acrylic is classified as a thermoplastic. [1] Thermoplastics soften when heated and harden when cooled, and this process can be repeated. Acrylic (PMMA) can be heated and formed into curves using line bending or vacuum forming, making it ideal for the phone stand in this product.
(c) One property of MDF that makes it suitable for the base of the desk organiser: MDF has a smooth, flat surface that can be easily coated with melamine laminate, producing a clean, professional finish with no visible grain or surface imperfections. [1] Unlike solid timber, MDF has no grain direction, so it does not split, warp, or move with changes in humidity, ensuring the base remains perfectly flat.
Answer Details
(a) Aluminium is a non-ferrous metal. [1] Non-ferrous metals are those that do not contain iron as their primary element. Aluminium is lightweight, corrosion-resistant, and non-magnetic, all characteristic properties of non-ferrous metals.
(b) Acrylic is classified as a thermoplastic. [1] Thermoplastics soften when heated and harden when cooled, and this process can be repeated. Acrylic (PMMA) can be heated and formed into curves using line bending or vacuum forming, making it ideal for the phone stand in this product.
(c) One property of MDF that makes it suitable for the base of the desk organiser: MDF has a smooth, flat surface that can be easily coated with melamine laminate, producing a clean, professional finish with no visible grain or surface imperfections. [1] Unlike solid timber, MDF has no grain direction, so it does not split, warp, or move with changes in humidity, ensuring the base remains perfectly flat.
