Scanning
Probe scanning uses a probe to trace the contour of an object. The probe then moves on a fraction of a millimeter and records another contour. If the original sculpture was not cut into sections then the probe and the laser would not be able to scan under the wings and legs. These are areas where other bits of sculpture are in the way and are termed "under-cuts".
The upper and lower body, front legs and wings have been probe scanned by Renishaw
Here the probe scanner can be seen scanning the upper body.
Surfacing
The scanned data of the upper body part shown was turned into .stl (stereo-lithography) files (see below) by Alias/Wavefront. Here are rendered images of the data collected for the upper body. part.
Manufacture
Before manufacture can begin the scanned data must be converted into .stl files 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.Components were scanned on 4 sides. These were used directly to programme "cutter-paths" for CNC (Computer Numerate Controlled) 3-axis milling machines. These machines are automated "drills" with coarse and fine heads that move 1) up/down, 2) back/forward, 3) left/right. The material being used in the project is a dense fibre called Cibatool BM 5120 that is manufactured by Ciba Speciality Chemicals
After fixing datums into the computer, machine paths are created. A drill cuts the contours of the object for each layer. The block of Cibatool is then turned 90 degrees and the next side is machined.
Finished Part
Some hand finishing is required to remove the supports that allowed this 3D part to be machined on a 3 axis machine.
Andy Lucas is here with the machined part at 50 x 50 x 60 cm
