Browsing by Subject "digital light processing"
Now showing 1 - 4 of 4
- Results Per Page
- Sort Options
Item Calibrating Large-area Mask Projection Stereolithography for Its Accuracy and Resolution Improvements(University of Texas at Austin, 2009-09-15) Zhou, Chi; Chen, YongSolid freeform fabrication (SFF) processes based on mask image projection such as digital micro-mirror devices (DMD) have the potential to be fast and inexpensive. More and more research and commercial systems have been developed based on such digital devices. However, a digital light processing (DLP) projector based on DMD has limited resolution and certain image blurring. In order to use a DLP projector in the large-area mask projection stereolithography, it is critical to plan mask images in order to achieve high accuracy and resolution. Based on our previous work on optimized pixel blending, we present a calibration method for capturing the non-uniformity of a projection image by a low cost off-the-shelf DLP projector. Our method is based on two calibration systems, a geometric calibration system that can calibrate the position, shape, size, and orientation of a pixel and an energy calibration system that can calibrate the light intensity of a pixel. Based on both results, the light intensity at various grayscale levels can be approximated for each pixel. Developing a library of such approximation functions is critical for the optimized pixel blending to generate a better mask image plan. Experimental results verify our calibration results.Item Digital Light Processing (DLP): Anisotropic Tensile Considerations(University of Texas at Austin, 2017) Aznarte, E.; Ayranci, C.; Qureshi, A.J.Digital light processing (DLP) 3D printing is an additive manufacturing (AM) process used to produce layered parts via photopolymerization. Anisotropy is a common characteristic of parts produced by DLP. Furthermore, printing conditions affect widely the resulting mechanical properties. This paper shows the effect of three printing factors on the final mechanical properties of specimens manufactured using DLP 3D printing. A series of ISO compliant tensile test specimens were designed, printed and tested. The properties analyzed were the elastic modulus, ultimate tensile strength, ultimate strain and printing time. Preliminary findings on design guidelines for Vat Photopolymerization processes are presented in addition to the economic effect of the studied parameters in terms of the total printing time.Item Mechanical Challenges of 3D Printing Ceramics Using Digital Light Processing(University of Texas at Austin, 2018) Roach, M.A.; Keicher, D.; Maines, E.; Wall, B.; Wall, C.; Lavin, J.; Whetten, S.; Evans, L.Digital light processing (DLP) 3D printing can be used for manufacturing complex structures using a variety of materials, which would be nearly impossible using traditional manufacturing methods. Recent work at Sandia National Laboratories uses DLP technology for additive manufacturing of complex alumina structures, using photocurable resins loaded with micron or submicron alumina particles. These resins are printed using a DLP 3D printer to produce a “green part.” The work presented here will discuss the mechanical challenges associated with printing alumina using commercially available DLP and stereolithography 3D printers, including the design of a custom DLP 3D printer to address identified mechanical challenges, thereby leading to improved print versatility and quality.Item MODELING AND CORRECTING ILLUMINATION INHOMOGENEITY OVER MULTIPLE DLP ILLUMINATION INTENSITIES FOR BETTER FABRICATION ACCURACY(University of Texas at Austin, 2023) Subedi, Saroj; Ware, Henry Oliver TenadooahWithin custom Digital Light Processing (DLP) systems, various small issues either in the optical assembly or with the DMD can lead to non-uniform illumination at the curing interface. This inhomogeneity leads to inaccurate dimensions of fabricated features over the full print area. To remedy this in our system, we have explored the relationship between LED output illumination, divided the illuminated area into a regional mesh, measured the light intensity and grayscale values over the mesh to obtain region-specific grayscale mask adjustments for illumination-leveling. This process involves producing grayscale mask by quantifiably balancing the light intensity values over build area and thus obtaining more uniform printed features. We compared the dimensional accuracy of features printed using full white pixel value images for 250µm features and those obtained using illumination-leveling grayscale processed images. Our results demonstrate the effectiveness of our method to obtain dimensionally accurate features, thanks to the achieved uniform illumination.