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1.1.6 Rapid Prototyping Technologies at a glance S.No Process Working Principal Principal Materials Cost Application 1 Stereolithography Low Power laser 2 Selective Laser Sintering 3 Laminated object Manufacturing 4 Fused Deposition Modelling 5 Laser Engineered Net Shaping beam is used to cure the models made by photo-sensitive resins. Uses a high power laser to fuse small particles into a mass representing the desired 3-D object. A Manufacturing process that uses CO2 laser to create successive cross sections of a three dimensional object Fused Deposition Modelling (FDM) is a solid-based rapid prototyping method that extrudes material, layer-by-layer, to build a model Fabricating metal parts directly from a solid model by using a metal powder injected into a molten pool created by a focused, high-powered laser beam. Photopolymer Resin $150k- Plastic, metal, ceramic or glass powders Thermoplastics such as PVC; Paper; Composites (Ferrous metals; Non-ferrous metals; Ceramics) ABS, ABS-M30, Polycarbonate, PC- ABS, PC-ISO, ULTEM, & PPSF (tan). Food-grade ABSi material Wide range of alloys, including titanium, stainless steel, aluminium, and other specialty materials; as well as composite and functionally graded materials. $400k $100k- $500k $200k- $800k $300k- $900k $250k- $1mil Producing models, prototypes, patterns & production parts. Prototypes, End parts Form/fit testing, Less detailed parts, Rapid tooling patterns Commonly used for concept design modelling, low volume production, prototyping, and production applications Repair & overhaul, rapid prototyping, rapid manufacturing, and limited-run manufacturing for aerospace, defense, and medical markets. 22
1.2 Fused Deposition Modeling A detailed discussion of the rapid prototyping method, FDM is necessary, considering the project revolves around certain improvements attempted in the process. Fused deposition modeling (FDM) is an extrusion based rapid prototyping technology which is the main area of research of this project. FDM was developed and patented in the year 1989 by Scott crump. Immediately after in 1990, he then setup Stratasys, a company which now specializes in manufacturing of additive fabrication machines for direct digital manufacturing. In 2007, almost half the amount of all fabrication systems worldwide was supplied by Stratasys making it a consecutive 6 th time market leader. FDM, in its working is quite similar to other rapid prototyping systems in which a STL file is fed into the fabrication machine which then builds the model layer by layer [6]. FDM mainly involves a feeder role or coil which is continuously fed into an extrusion head or nozzle. Before the material reaches the nozzle, it is heated to soften the material to a molten state when it can be deposited onto the platform. This is done with the help of heating elements in nozzle which melts the material. This nozzle is controlled by a computer aided manufacturing package which can be used to move the nozzle in horizontal, vertical directions. This whole setup is carried out in a temperature controlled chamber to maintain the quality of the produced parts. As the molten material ejects out of the nozzle, it is then spread onto the platform in the desired shape as a layer. The deposition platform is then lowered to a height equal to one layer height of the part and the deposition process is repeated over the previously deposited layer. This process is repeated layer by layer starting from the base and worked its way to the top to complete the whole model. One of the important parts of this type of deposition process is the nozzle or the extrusion head which is responsible for melting the material and its deposition. The nozzle is computer controlled and it can be moved in horizontal and vertical directions. A FDM schematic is shown below in Fig 1.7 23
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 and 18: 1.1.1 Stereolithography Stereolitho
Page 19 and 20: The object to be made is first mode
Page 21: 1.1.5 Laser Engineered Net Shaping
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
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on the mechanical properties and po
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3.5.1 Silicone with other materials
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Fab@home machine. Since our require
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are printed using the two suitable
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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
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4.3 Taguchi methods There are two t
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Such steps usually identify the nee
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Nominal is best Larger is better S
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Control of material flow - The lead
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Fig 4.3 Parts being tested with Hou
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values in all cases are almost doub
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level. The other parameters were in
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The finite element method has had a
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performance of finished FDM parts [
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ehaviour with failure occurring at
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Fig. 2 (a) is the thin curved part
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Table 5.1 Property data: Fabepoxy M
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optimum number. The final finite el
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Fig. 5.11 Load and boundary conditi
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overall deflection pattern of two s
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Fig. 5.13 Variation of compressive
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Fig. 5.15 shows the overall deforma
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The effectiveness of the deposition
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[11] M. Greul, T. Pintat, M. Greuli
Page 127 and 128:
[32] Philip J. Ross, 1988, “Taguc
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