Marking out is to transfer a line or shape onto the material you are working with as a guide to cut, shape or mould your material. This must be accurate to ensure that your end product is the correct measurements and proportions. Some of the tools used for marking out will be used on all types of material you work with such as:
Steel rule - accurate straight line measurements
Outside calipers - measures round rods
Inside callipers - measures holes
However some tools will be changed for the different materials some tool may not be easily marked on, for example when marking a line on wood a pencil will be used, this shows up on wood however if you tried to mark a line in pencil on metals and plastics their surfaces would not take the mark, so we change the tool for marking out to something that will show up, below is a list of tools used and with which material:
Drawing a line:
Wood - Pencil
Metal - Scribe
Plastic - Felt tip pen
Lines at right angles from the edge:
Wood - Carpenters try square
Metal & Plastic - Engineers try square
Marking a circle:
Wood - Pair of compasses
Metal & Plastic - Dividers
Marking the centre of a hole:
Wood - Pencil
Metal - Centre punch
Plastic - Felt tip pen
Parallel lines to the edge:
Wood - Marking gauge
Metal & plastic - Odd legged callipers
Line the rule up with the end of the material and use the scriber to draw a line, to show the accurate mark point use and arrow (>)
Engineers square: Used for marking out lines square to the face side or face edge, Engineered squares have a metal stop as oppose to a wood stop found on try squares. Do not assume students know how to use a try square.
Common problems with students:
Use a ball pain hammer with your centre punch; place your metal onto a metal plate or block as wood can create bounce, lay the centre punch down and line up the point lift it up and used a single sharp tap to the end of the hammer.
Measuring
Commonly used tools:
Insider callipers- measure inside
Outsider callipers- measure outside
Dividers- rounding off/ marking out corners
Odd legged callipers- mark parallel to an edge
Venire callipers: accurate measurements
Micrometer: accurate measurements
Steel rule - accurate straight line measurements
Outside calipers - measures round rods
Inside callipers - measures holes
However some tools will be changed for the different materials some tool may not be easily marked on, for example when marking a line on wood a pencil will be used, this shows up on wood however if you tried to mark a line in pencil on metals and plastics their surfaces would not take the mark, so we change the tool for marking out to something that will show up, below is a list of tools used and with which material:
Drawing a line:
Wood - Pencil
Metal - Scribe
Plastic - Felt tip pen
Lines at right angles from the edge:
Wood - Carpenters try square
Metal & Plastic - Engineers try square
Marking a circle:
Wood - Pair of compasses
Metal & Plastic - Dividers
Marking the centre of a hole:
Wood - Pencil
Metal - Centre punch
Plastic - Felt tip pen
Parallel lines to the edge:
Wood - Marking gauge
Metal & plastic - Odd legged callipers
Line the rule up with the end of the material and use the scriber to draw a line, to show the accurate mark point use and arrow (>)
Engineers square: Used for marking out lines square to the face side or face edge, Engineered squares have a metal stop as oppose to a wood stop found on try squares. Do not assume students know how to use a try square.
Common problems with students:
- Students may be used to working in Centimetres not millimetres
- A steel rule starts at 0 unlike conventional school rulers.
- Some students may not take into account the burr and may mark out incorrectly
Use a ball pain hammer with your centre punch; place your metal onto a metal plate or block as wood can create bounce, lay the centre punch down and line up the point lift it up and used a single sharp tap to the end of the hammer.
Measuring
Commonly used tools:
Insider callipers- measure inside
Outsider callipers- measure outside
Dividers- rounding off/ marking out corners
Odd legged callipers- mark parallel to an edge
Venire callipers: accurate measurements
Micrometer: accurate measurements