Directories, Stereolithography, Prototype, Three-Dimensional Graphics, Computer-Aided Design, Computer-Aided Manufacturing, Light Sculpting Inc. -- Product information, Helisys Inc. -- Product information, Light Sculpting LSI-1115MA (CAD/CAM system) -- Design and construction, Helisys LOM-2030 (CAD/CAM system) -- Design and construction, Quadrax Laser Technologies Mark 1000 Laser Modeling System (CAD/CAM system) -- Design and construction, Computer-aided manufacturing, Stereolithography -- Usage, and CAD-CAM systems industry -- Product information
There are several technologies for rapid prototyping, a manufacturing technique in which the prototype of a part is created in hours rather than weeks. Rapid prototyping systems use three dimensional computer-aided design (CAD) files, slicing the image into cross sections and constructing layers of solid material, bonding each to the one before it. 3D Systems Inc $385,000 SLA 190 uses stereolithography and focuses an ultraviolet light onto a liquid polymer. It can produce a 20X20X20 inch part in 3 hours. Stratasys Inc's $178,000 3D Modeler uses fused deposition modeling to produce a 12X12X12 inch part in under five hours. Helisys' $110,000 LOM-2030 uses laminated object modeling to create a 20X30X20 inch part in 15 to 30 hours. Light Sculpting Inc offers the $129,700 LSI-1115MA which produces an 11X11X15 inch part at 40 seconds per layer. Quadrax Laser Technologies Makes the $195,000 Mark 1000 Laser Modeling System which uses laser modeling to produce a 12X12X12 inch part in six to twenty-four hours.
Rapid Prototyping, Manufacturing, Technology, Flexible manufacturing systems, Testing, Stereolithography, Computer-Integrated Manufacturing, United States. Sandia National Laboratories -- Research, and Flexible manufacturing systems -- Innovations
Researchers at Sandia National Laboratory in Albuquerque, NM, are ecstatic over the endless possibilities of rapid prototyping for speeding up computer-aided design and manufacturing. Their report at the Rapid Prototyping and Manufacturing Conference in May 1993 on the modeling of a bicycle crank arm highlighted the advantages of rapid prototyping over traditional techniques. The experiment, which used the stereolithography technique and the selective laser sintering approach, yielded production-like prototypes in just five days. Conventional methods usually take several months. In a related development, the process' speed improvement was instrumental in winning over a customer of Sundstrand Aerospace's Electric Power Div. The customer had asked for a current-transformer/electromagnetic interference module to be repaired in four months' time. Rapid prototyping enabled Sundstrand to make a model one month after the project's start.
SUMMARY A study was undertaken to determine the dimensional accuracy of anatomical replicas derived from X-ray 3D computed tomography (CT) images and produced using the rapid prototyping technique of stereolithography (SLA). A dry bone skull and geometric phantom were scanned, and replicas were produced. Distance measurements were obtained to compare the original objects and the resulting replicas. Repeated measurements between anatomical landmarks were used for comparison of the original skull and replica. Results for the geometric phantom demonstrate a mean difference of + 0.47 mm, representing an accuracy of 97.7-99.12%. Measurements of the skull produced a range of absolute differences (maximum +4.62 mm, minimum +0.1 mm, mean +0.85 mm). These results support the use of SLA models of human anatomical structures in such areas as pre-operative planning of complex surgical procedures. For applications where higher accuracy is required, improvements can be expected by utilizing smaller pixel resolution in the CT images. Stereolithographic models can now be confidently employed as accurate, three-dimensional replicas of complex, anatomical structures. [ABSTRACT FROM AUTHOR]
Presents the background to and efforts being made to find a direct production route using rapid prototype (RP) parts as the electrodes for electrical discharge machining (EDM). It would have the double effect of unlocking the potential of the EDM die sinking process and expanding the role of RP in the production environment. Thin coated stereolithography (SL) models have been used to erode hardened tool steel to a depth of 4mm. Machining efficiency of these copper coated RP models is not comparable to that of conventional machined solid copper electrodes. Parametric optimization has been applied, achieving substantial improvements in machining efficiency. At present these electrodes are suitable for semi-roughing or finishing cuts in EDM die sinking. Electroforming copper into SL cavities shows potential for manufacture of electrodes with comparable performance to that of solid copper. [ABSTRACT FROM AUTHOR]
We investigate the accuracy of complex anatomical replicas derived from X-ray computed tomography data linked to the rapid prototyping technique of stereolithography. Data processing by specific softwares (segmentation, three-dimensional interpolation) allows direct interfacing with the stereolithography apparatus to build a resin replica with reproduction of internal cavities. Our preliminary results about surface and dimensional accuracies suggest that the reproduction of complex anatomical structures by stereolithography is reliable enough to be used for surgical planning, for custom-made implants and for surgical anatomy teaching. [ABSTRACT FROM AUTHOR]
Ceramic three-dimensional parts can be produced by a stereolithography (SL) process using a ceramic suspension containing alumina powder, UV curable monomer, diluent, photoinitiator and dispersant. The monomer reacts to UV radiation (argon ionized laser) and is transformed into a solid polymer which is then removed by thermal treatment (debinding). Subsequent sintering of green parts leads to dense ceramic parts. The effect of each component on the rheology of the alumina suspensions has been studied first. Both the addition of dispersant and diluent and the increase in temperature allow a significant decrease of the viscosity of the suspensions. The highly loaded (more than 55 vol. per cent), homogeneous and stable suspensions have a shear thinning behaviour which is favourable for casting the layers. Adequate cured depth (above 200μm) and satisfactory transversal resolution have been obtained and these allow the production of ceramic parts, which demonstrates the feasibility of the process. Sintering at 1,580°C leads to dense ceramic parts with homogeneous microstructure. The process still needs to be optimized to improve even more the mechanical properties. [ABSTRACT FROM AUTHOR]
At The Institute of Physical and Chemical Research (RIKEN) a new process named multiple LED photographic curing (MPC) has been developed. As a matter of priority, MPC is thought to be applied to concept modelling. The building data are available in bitmap or voxel representation respectively. In MPC, light is generated by light-emitting diodes (LEDs). Exposing of a photopolymer happens through raster scanning. An array of multiple beams of light is projected onto the resin surface while the scan head moves across the vat. The fabrication of test parts has proven the system's practical ability to create geometric objects. Surface finish is quite good, certainly adequate for most concept verification. Some obstacles such as low exposure energy have yet to be overcome. Scaling up the build envelope enables fabricating much larger parts. [ABSTRACT FROM AUTHOR]
Rapid prototypes formed using stereolithography (SL) method have to undergo post-curing to increase their strength and rigidity. This study attempts to reduce, if not eliminate, post-cure distortion by characterising curing behaviours. Curing (both heat and UV initiated) characteristics of an acrylic-based photopolymer under actual fabrication conditions were studied using Raman spectroscopy as well as differential scanning calorimetry (DSC) and differential scanning photo-calorimetry (DSP). Specimens of single photopolymer lines were created using a SL machine. Raman spectroscopy was used to quantify the curing percentage at different areas on the cross-section of these lines. Curing percentages before and after post-curing were also obtained from the experiments. Difference in percentage of post-curing gave an indication of the distortions faced. It was found that uncured and partially cured resins trapped within the photopolymer resulted in inhomogeneity of curing in the specimens causing shrinkage and distortion. [ABSTRACT FROM AUTHOR]