Scanning
Laser scanning uses a beam of light to trace the contour of an object. The laser record points in space as it moves fractions of a millimeter. If the original sculpture was not cut into sections then the laser would not be able to scan under the head. The areas where other bits of sculpture are in the way are termed "under-cuts".
The head has been laser scanned by 3Dscanners
Surfacing
Here is an image of the point data collected for the head and also a rendered image of the head. The image is made after surfaces are placed between the data points.
Manufacture
The head was being made by Land Rover at Warwick University's Rapid Prototyping and Technology Centre. The scanned data of the head is being turned into .stl (stereo-lithography) files and will be made by rapid prototyping.
The files are made of tiny triangles that cover the scanned area. The smaller the triangles then the more data captured. Some of the scanning cannot capture every single point on the object but if there is the tiniest gap in the computer scan then the manufacturing process will not work. This means that gaps have to be filled manually. If your object is very detailed then this can take some time.
The process used is a form of RP (Rapid Prototyping) called SLA -Stereolithography. A layer of clear resin is laid down onto the layer below to the contour of the object for each layer. Delcam did the programming for the manufacture of the head and co-ordinated Williamson Park with Rover Group.
If the machine was starting from the base a standing figure then it would begin by cutting the soles of the feet
, then the ankles, the knees etc. Each layer is only a tenth of a millimeter thick so it would
take 500 layers to make a foot!
Finished Part
The final section is about 50 x 50 x 60 centimetres. Anthony is standing with the head.
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