RAPID PROTOTYPING.ppt (Size: 4.48 MB / Downloads: 475)
Rapid Prototyping (RP) techniques are methods that allow designers to produce physical prototypes quickly.
It consists of various manufacturing processes by which a solid physical model of part is made directly from 3D CAD model data without any special tooling.
The first commercial rapid prototyping process was brought on the market in 1987.
Nowadays, more than 30 different processes (not all commercialized) with high accuracy and a large choice of materials exist.
These processes are classified in different ways: by materials used, by energy used, by lighting of photopolymers, or by typical application range.
What is Rapid Prototyping?
A CAD technique to allow “Automatic” creation of a physical model or prototype from a 3-D model.
Create a 3-D “Photocopy” of a part.
Computer Real life
Why use Rapid Prototyping?
Decreases lead time
Facilitates concurrent engineering
Allows visualization of more ideas
The Rapid Prototyping Technique
In the Rapid Prototyping process the 3D CAD data is sliced into thin cross sectional planes by a computer.
The cross sections are sent from the computer to the rapid prototyping machine which build the part layer by layer.
The first layer geometry is defined by the shape of the first cross sectional plane generated by the computer.
It is bonded to a starting base and additional layers are bonded on the top of the first shaped according to their respective cross sectional planes.
This process is repeated until the prototype is complete.
.Layer by Layer Construction
The fourth step is the actual construction of the part.
RP machines build one layer at a time from polymers, paper, or powdered metal.
Most machines are fairly autonomous, needing little human intervention.
.Clean and Finish
The final step is post-processing. This involves removing the prototype from the machine and detaching any supports.
Some photosensitive materials need to be fully cured before use
Prototypes may also require minor cleaning and surface treatment.
Parts used for functional tests
Manufacturing of medical models
Form –fit functions for assembly tests
Possibility of manufacturing parts which are impossible to be produced conventionally in a single process
Can be fully automized and no supervision is required.
No geometric limitations
Necessity to have a support structure
Require labor for post processing and cleaning.