4.4.1 Background
 
 

Resource Recovery Systems (Pty.) LTD, specializing in electro-forming presented a nickel plated sea-horse. This was made from an original sea horse. The focus of this case study was to capture the geometry from actual specimen, a sea horse, and use it in the jewelry industry.

The CSIR’s high resolution Phillips CAT scanner was used. The sea horse was fitted in the rotary table, secured with prestik putty. CAT images were taken 0,2mm thick and 0,2mm intersections. This data was stored on the UNIX based computer.

Please refer to section 3.7.1.2 for more detail regarding data retrieving and apparatus.
 
 

4.4.2 Conclusion
 
 

This is again the ideal method for capturing detailed, complex and low accuracy geometry. This small specimen needed to be scanned at a minimum of 0,2mm slice and intersections to capture the geometry. The 486 UNIX based computer needs to be upgraded to accommodate larger sets of data storage and processing. It therefore requires larger hard drive, RAM capacity as well as a faster processor. CAT scanning can be done overnight if properly planned.

Only sets of maximum 16 images could be converted simultaneously. The FDM rapid prototyping machines produced the scaled up 2:1 version of the head.
 
 
 
 

4.4.2.1 Images
 
 
 

Figure 4.4.2.1 3D reconstruction of the Sea Horse.	Figure 4.4.2.2  3D reconstruction of the Sea Horse.
Figure 4.4.2.3 3D reconstruction of the Sea Horse.	Figure 4.4.2.4 FDM Prototype of the Sea Horse, scale 2:1.

 
 

4.4.3 Sea-horse Data Sheet:
 
 

	Description	Options (Default)	Data
1	CT Image Names		shorse_1.01
2	Patient/Project Name		seahorse.pat
3	Number of First Input Image		seahorse00
4	Number of Last Input Image		seahorse85
5	Number of First Output Image		000
6	CT or MRI	CT, MRI	CT
7	Horisontal Nr. Of Image Pixels	0 to 65535 (265,512,1024)	512
8	Vertical Nr. Of Image Pixels	0 to 65535 (265,512,1024)	512
9	Number of Images per File	(1)	1
10	File Swap Format (0,3)	0,3	3,CCUNF
11	Pixel Type	B,UB,S,US,L,UL,F	US
12	Header Size	*see formula below	0
13	Inter Image Header Size	0	0
14	Add Value	0 to 4095	DEFAULT
15	Scale Value	0 to 4095	DEFAULT
16	Table Position	(mm)	30.2
17	Distance Between Slices	(mm)	0.2
18	Slice thickness	(mm)	0.2
19	Pixel Size SQ.	F.O.R./Nr. Hor. Pixels (mm)	0.078125
20	Gantry Tilt Angle	Degrees	0
21	Field of Reconstruction/View	(mm)	40
22	Number of Images		85
23	File Size of CAT Image	kb	315
24	File Size of Converted Image	kb	265
25	.3dd file size	Mb	0.198
26	.STL file size	Mb	14.31
27	RP Method	(SLA,FDM,OTHER)	SLA
28	.IGS file size	Mb	-
29	RP Slice file size	Mb	12
30	RP Download File size	Mb	13
31	Grow Time	Hour	4
32	Tip size	(T12, T25)	T12
33	Slice Thickness	(0.01", 0.014")	0.01"
34	Finishing Time	Hour	1
35	Processing Time	Hour	5
36	Data Retrieval Time	Hour	6
37	Total Cost	Rand	=11*150+ =1650