Evaluation of 3D Printers

3D Printing is an aspiration for many educational institutions.  Currently, 3D printing technology is becoming one of the new key technologies. It enables companies to cut costs, shorten their time-to-market, helps them to produce stronger and lighter parts and improve their efficiency. For that reason, it is important that students understand the technology of the future global economy. In the US and other places, already summer camps have been set up to teach 3D printing techniques over the summer. Children from a young age get to explore the subject of additive manufacturing. 3D printing  works by starting with a digital model in a 3D CAD (Computer-Aided Design) file and then creating a physical three-dimensional object. An object is scanned - or an existing scan of an object is used, which is processed by a piece of software known as a “slicer.” The slicer converts the model into a series of thin, 2-dimensional layers and produces a file with instructions (G-code)...

The beauty of 3D printing is that it’s a simple technology that can be applied to all sorts of fields. It’s lowered the barrier for anyone to design and create and opened up opportunities to streamline processes already in place. The Top 5 applications of 3D Printing are, Education Prototyping Manufacturing Medicine Construction Jewellery Additive manufacturing's earliest applications have been on the  toolroom  end of the manufacturing spectrum. For example,  rapid prototyping  was one of the earliest additive variants, and its mission was to reduce the  lead time  and cost of developing prototypes of new parts and devices,  which was earlier only done with subtractive toolroom methods such as CNC milling and turning, and precision grinding, far more accurate than 3d printing with accuracy down to 0.00005" and creating better quality parts faster, but sometimes too expensive for low accuracy prototype parts

Description Laminated object manufacturing is a rapid prototyping system developed by Helisys Inc. In it, layers of ad hesive-coated paper, plastic, or metal laminates are successively glued together and cut to shape with a knife or laser cutter. Like all 3D-printed objects, models made with a LOM system  start out as CAD files . Before a model is printed, its CAD file must be converted to a format that a 3D printer can understand — usually STL or 3DS. The main components of the system are a feed mechanism that advances a sheet over a build platform, a heated roller to apply pressure to bond the sheet to the layer below, and a laser to cut the outline of the part in each sheet layer. Parts are produced by stacking, bonding, and cutting layers of adhesive-coated sheet material on top of the previous one.  A laser cuts the outline of the part into each layer. After each cut is completed, the platform lowers by a depth equal to the sheet thickness (typically 0.002...

Selective Laser Melting   (SLM) allows the manufacture of functional components with high structural integrity at a low cost and is compatible with various materials, including biocompatible titanium alloys.  Selective laser melting uses a laser to melt successive layers of metallic powder. The laser will heat particles in specified places on a bed of metallic powder until completely melted. The CAD 3D file dictates where melting will occur. Then, the machine will successively add another bed of powder above the melted layer, until the object is completely finished. SLM is a powder bed AM technology in which parts are fabricated layer by layer using the action of a high-energy beam on a powder bed. In this process, the powders are fully melted and solidified. The process is very similar to the SLS process but the energy of the beam is much higher and the process is performed under a controlled atmosphere. SLM is currently very popular for the fabrication of metallic ...

Many Powder Bed Fusion devices also employ a mechanism for applying and smoothing powder simultaneous to an object being fabricated, so that the final item is encased and supported in unused powder. Types of 3D Printing Technology:  Selective Laser Sintering (SLS) Materials:  Thermoplastic powder (Nylon 6, Nylon 11, Nylon 12) Dimensional Accuracy:  ±0.3% (lower limit ±0.3 mm) Common Applications:  Functional parts; Complex ducting (hollow designs); Low run part production Strengths:  Functional parts, good mechanical properties; Complex geometries Weaknesses:  Longer lead times; Higher cost than FFF for functional applications Creating an object with Powder Bed Fusion technology and polymer powder is generally known as Selective Laser Sintering (SLS).  Next, a recoating blade or wiper deposits a very thin layer of the powdered material  typically 0.1 mm thick onto a build platform. A CO2 laser beam then begins to scan the surface...

Looking at Digital Light Processing machines, these types of 3D printing technology are almost the same as SLA. The key difference is that DLP uses a digital light projector to flash a single image of each layer all at once (or multiple flashes for larger parts). Because the projector is a digital screen, the image of each layer is composed of square pixels, resulting in a layer formed from small rectangular blocks called voxels. DLP can achieve faster print times compared to SLA. That’s because an entire layer is exposed all at once, rather than tracing the cross-sectional area with the point of a laser. A DMD is an array of micro-mirrors that control where light is projected and generate the light-pattern on the build surface.