2.7 Accuracy in design and manufacture

accuracy

the amount of conformity of a measurement to the required value

tolerance

acceptable upper and lower limits of accuracy of a measurement

measurement

process of using tools to check existing dimensions

dimensions

the measured distance in a straight line between features of a part or a product such has height or length

marking out

the transfer of designs onto materials or parts

marking out metal

uses a high carbon steel scriber that can scratch the surface since its a harder material, special ink can be used to make the marks more visible

Beam compasses/ trammel heads

To mark out large circles

datum

a surface or edge used as a reference from which measurements are taken to improve accuracy

micrometers

a tool used to accurately measure with fine tolerances

vernier calipers

Used in determining precise internal or external measurements. Measuring capacity is 6-72 inches or 150-1800 millimeters.

Co-ordinate measuring machinery (CMMs)

the tools used for precise measurements within manufacture

impact of CNC machinery

makes accuracy and efficiency easier since it uses software to create an accurate part that reduces the chance of human error

importance of accuracy

if parts are not accurate they may nit fit within the product wasting materials and time

testing

when creating a product the tolerance allowed on each part needs to be known and specified so waste is not created

measuring aids

help improve accuracy and speed within production eliminating potential human errors

JIGS

device used to control the motion of a tool such as a drill relative to a work piece

fixtures

a robust frame with holding holding points and clamps to hold product components firmly in place for manufacturing processes such as welding

templates

rigid shape or pattern used to transfer a design onto a workpiece to ensure consistency