Shaping Flashcards
What is casting?
Used to make three-dimensional shapes from metal
What is sand casting used to make?
Metal parts
What is first step of sand casting?
Make wooden version of product you want to make - pattern
usually spilt in half
Why should the pattern have no sharp corners in sand casting?
Difficult to cast
may cause areas of high stress in casting
What is the drag in sand casting?
Bottom half of the patter put into the box
What is the second step of sand casting?
Sand is poured in until drag is full
What is the third step of sand casting?
Drag is then turned over and pattern is taken out
What is cope in sand casting?
Top part of pattern used to make cavity
includes hole for metal to be poured in (spruce) and channels for metal to move
riser used excess liquid metal
What is the fourth step of sand casting?
Drag and cope assembled together to form complete model
What is the fifth step of sand casting
Liquid metal is poured in
sand is knocked off and shaken off casting
mould only used once
What is sand casting used for?
Single part/small batch of parts
Why would it take long time to produce lots of parts of same design with sand casting?
For sand moulds to line up perfectly each time
parts made might not be exactly the same
What is a die?
Mould-made out of metal
Disadvantage of die
Expensive to make
Why does die have to be made from metal with a higher melting point than one being cast?
Can be machined to a smooth finish
