Production Aids With Timber Based Materials (AQA GCSE Design & Technology): Revision Note
Exam code: 8552
The use of production aids with timbers
Production aids are used with natural timbers and manufactured boards to control measurements, locate components and guide cutting, drilling, routing and assembly
Timber products often contain several separate parts, so consistent dimensions and hole positions are essential if the parts are to fit together
Typical materials include pine, beech, plywood, MDF and chipboard
Measuring and reference points for timbers
Measuring and reference points are used to locate cuts, holes, joints and components from a fixed datum face or datum edge
Timber is often prepared with one flat face and one square edge
These become the face side and face edge from which all marking out is referenced
A try square, steel rule, marking gauge, mortise gauge or combination square can transfer accurate measurements onto the material
A marking knife or sharp pencil creates fine reference lines
A centre punch or bradawl can create a starting point for drilling
Centre lines help locate holes in the middle of a board for dowel
Witness marks identify parts that belong together
Taking all measurements from the same datum avoids cumulative error and helps joints align during assembly
Examples include:
Face side and face edge marks
A centre line for drilling a dowel hole
Witness marks on matching frame parts
A marking gauge line for a rebate
Worked Example
Explain why a cabinet maker marks a face side and face edge before measuring the positions of joints.
[2 marks]
Answer
The face side and face edge provide two fixed datum surfaces. [1] All measurements can be taken from the same references, reducing errors and helping matching joints and components line up accurately. [1]
Templates and patterns for timbers
A timber template is a reusable shape used to mark or guide the production of identical components
Templates are commonly made from MDF, plywood or acrylic
These materials are flat, stable and easy to shape accurately
The outline can be drawn around before sawing, or the template can guide a router fitted with a bearing or guide bush
Templates are useful for irregular or curved shapes that would take a long time to measure and draw repeatedly
Reference holes or alignment marks may be added so the template is positioned in the same place on every workpiece
Templates can be used with CAD/CAM as one accurate CAD file may be used repeatedly by a laser cutter or CNC router
Examples include:
A curved chair-leg template
A MDF pattern for a wooden toy
A routing template for a recessed hinge
A drilling pattern for a flat-pack panel
Worked Example
Explain why an MDF template is suitable for marking out a batch of identical wooden toy parts.
[2 marks]
Answer
MDF is flat, stable and easy to shape accurately. [1] The maker can draw around the same template for each part, making the outlines repeatable and reducing marking-out time and errors. [1]
Examiner Tips and Tricks
Remember to use the word 'template' not 'pattern' in answers about timber. In Textiles, a pattern has a precise meaning, which is a paper plan pinned to fabric and cut directly through it. For timber, examiners expect the word template, not pattern, when you are describing a reusable shape used to mark or guide cutting.
Jigs for timbers
A timber jig holds and locates a workpiece
It often guides a cutting or drilling tool during a repeated operation
A drilling jig can include guide holes or metal drill bushes
This ensures that holes are drilled at the same angle, depth and position
An assembly jig holds components at the correct angle while screws, dowels, adhesive or other joints are added
A cutting jig can guide a saw or router
A mitre box guides a saw at a fixed angle such as 45 degrees or 90 degrees
Stops allow every workpiece to be placed in the same position without measuring again.
Clamps secure the workpiece and improve safety, accuracy and quality
Jigs can be simple and inexpensive for a small batch, or durable and adjustable for repeated industrial production
Examples include:
A dowel-drilling jig
A mitre box
A 90-degree frame assembly jig
A router jig for a hinge recess
Worked Example
Describe how a drilling jig could be used to make matching dowel holes in 30 flat-pack furniture panels.
[2 marks]
Answer
The jig would locate against the same datum edges of every panel. [1] Guide holes or drill bushes would control the drill position and angle, and a depth stop could control depth. This makes the dowel holes line up when the panels are assembled. [1]
Examiner Tips and Tricks
When describing accuracy consider the alternative, less accurate method of doing the task, typically by hand.
It helps to think about yourself doing the task in a typical school workshop. This will help you to identify the potential reason why and how more accuracy is achieved.
Unlock more, it's free!
Join the 100,000+ Students that ❤️ Save My Exams
the (exam) results speak for themselves:
Was this revision note helpful?
