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the process of recoating, many stereolithography systems drew a knife edge to smoothen the surface. Upon completion of the process the object is elevated from the vat and allowed to drain. Excess resin from is removed manually from the surface of the object. The object is then given a final cure by bathing it in intense light in a closed box similar to oven. After the final cure, supports are cut off and the surfaces are sanded or otherwise finished. 1.1.2 Selective Laser Sintering Selective laser sintering was first commercialized in the 1987 by DTM Corporation. SLS was developed and patented by Dr Carl Deckard. Unlike other manufacturing processes such as Stereolithography and Fused deposition modeling, SLS does not require support structures due to the fact that part being constructed is surrounded by unsintered powder at all times. In this type of process a high power laser is used to fuse small particles of plastic, metal into a desired three dimensional object. Fig 1.4 Selective Laser Sintering An SLS setup is shown in figure 1.4. SLS has the capability to be used with a wide variety of materials like green sand, metals and polymers for different applications. 18
The object to be made is first modeled in CAD software, which is then converted into a STL file. The STL file is a format which contains the whole model in a slice by slice data readable by the corresponding machinery. This file is fed to the machine after which the processing starts. A roller filled with material is used spread the material over a platform which is built up one on top of another. A laser is then used to follow a pattern over a set of points with the information provided in the STL file. The path were the laser is traced is sintered. The platform is then lowered to a height equal to one slice of the model and another layer of powder is deposited over the previous layer. [3] 1.1.3 Laminated Object Manufacturing Laminated Object Manufacturing is a process in which layers of adhesive coated paper, plastic or metal are glued together to make three dimensional models. Fig 1.5 shows a setup of laminated object manufacturing. Fig 1.5 Laminated Object Manufacturing The principal US commercial provider of Laminated Object manufacturing was Helisys, which ceased operation in 2000. However, the company‟s products are still sold and serviced by a successor organization, Cubic technologies. 19
Page 1 and 2: An Investigation into curved layer
Page 3 and 4: Contents Abstract..................
Page 5 and 6: 3.5.2 Fabepoxy.....................
Page 7 and 8: methodology to print simple curved
Page 9 and 10: List of Figures 1.1 The Rapid proto
Page 11 and 12: 4.3 Parts being tested with Hounsfi
Page 13 and 14: List of Abbreviations 3D: Three dim
Page 15 and 16: Fig 1.1 The Rapid prototyping Cycle
Page 17: 1.1.1 Stereolithography Stereolitho
Page 21 and 22: 1.1.5 Laser Engineered Net Shaping
Page 23 and 24: 1.2 Fused Deposition Modeling A det
Page 25 and 26: Fig 1.8 Deposition Head Different t
Page 27 and 28: 900mc is capable of producing parts
Page 29 and 30: noted that the parts built in this
Page 31 and 32: structure. Honeycomb scaffold archi
Page 33 and 34: optimal direction to build a part t
Page 35 and 36: processing treatment was analyzed w
Page 37 and 38: The actual influence of the curved
Page 39 and 40: Separating the Main part with its s
Page 41 and 42: limited to simple models. It could
Page 43 and 44: Fig 2.2 Faces, Edges and Vertices o
Page 45 and 46: 2.1.5 Constructive Solid Geometry C
Page 47 and 48: A STL file is a triangular represen
Page 49 and 50: Fig 2.8 A sample Binary STL File Sl
Page 51 and 52: Different processes may either vary
Page 53 and 54: At the very outset of generating th
Page 55 and 56: and correction of each point to sat
Page 57 and 58: apid prototyping machine are remove
Page 59 and 60: Fig 2.13 Main Part Fig 2.14 Support
Page 61 and 62: As this text file is to be used wit
Page 63 and 64: mounted to the axes carriage. Timin
Page 65 and 66: Fig 3.1 The deposition head At the
Page 67 and 68: 3.2.3 Assembling Electronics and ca
Page 69 and 70:
microcontroller is now disconnected
Page 71 and 72:
The relationship between test point
Page 73 and 74:
on the mechanical properties and po
Page 75 and 76:
3.5.1 Silicone with other materials
Page 77 and 78:
Fab@home machine. Since our require
Page 79 and 80:
are printed using the two suitable
Page 81 and 82:
The support structure‟s dimension
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machine Fig 3.13 Flat and curved la
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4.1 Experimental conditions Chapter
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have many factors from contention a
Page 89 and 90:
4.3 Taguchi methods There are two t
Page 91 and 92:
Such steps usually identify the nee
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Nominal is best Larger is better S
Page 95 and 96:
Control of material flow - The lead
Page 97 and 98:
Fig 4.3 Parts being tested with Hou
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values in all cases are almost doub
Page 101 and 102:
level. The other parameters were in
Page 103 and 104:
The finite element method has had a
Page 105 and 106:
performance of finished FDM parts [
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ehaviour with failure occurring at
Page 109 and 110:
Fig. 2 (a) is the thin curved part
Page 111 and 112:
Table 5.1 Property data: Fabepoxy M
Page 113 and 114:
optimum number. The final finite el
Page 115 and 116:
Fig. 5.11 Load and boundary conditi
Page 117 and 118:
overall deflection pattern of two s
Page 119 and 120:
Fig. 5.13 Variation of compressive
Page 121 and 122:
Fig. 5.15 shows the overall deforma
Page 123 and 124:
The effectiveness of the deposition
Page 125 and 126:
[11] M. Greul, T. Pintat, M. Greuli
Page 127 and 128:
[32] Philip J. Ross, 1988, “Taguc
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