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This viewer displays slice cross sections and their respective fill patterns. A digital readout at the bottom of the screen gives the ability to extract measurements from this file. This information is helpful in determining the files integrity and getting a view of slice-by-slice formation. This slice-by-slice file is the code the machine will use to generate a layer-by- layer creation of the model.
To access this function you must select the Bview button from the menu. There are several different functions that you can implement to render the model and file exactly how you desire it to be prior to building. The Navigation buttons allow you to view the model slice by slice or at 10 percent increments, the Automated Control button gives you a real time build slice by slice, the Zoom buttons allow you to adjust the view of the model on the screen, and the Pan buttons allows you to adjust the -x and -y plane views of the model.
Together, all of these functions give the modeller complete control over not only how the machine will build the part, but the customization of the part prior to the build. Initially, you can check the material reservoirs to determine if you need to add any build or support materials.
The computer will tell you if additional material is needed and how much to add. But while you are waiting you can check the optical tape receptacle to make sure it is empty and you can mill the substrate.
Mill the original surface dull finish of the substrate until it has a clean, bright finish. This ensures that the surface is level. The next and most important step is to check the jet-firing status.
Before each use, perform a manual purge to refill the jet reservoir with material and make sure that the proper amount of air is within the reservoir also. Cut a 3-inch piece of plastic tubing, remove the purge cap, and place the tube on the purge spout.
Once the jet has been selected, another menu will appear that will prompt your actions, from this menu, choose the purge command. Allow the jet to purge until you get an even flow of material into the tube container and allow it to flow for 2 to 3 seconds, and then press any key to stop the purge.
Immediately remove the tube from the spout and reapply the cap. After making sure that the jets are firing properly, go back into new build, select the file you want, and build. Post-processing: The post-processing procedure is a process that must be monitored very carefully. When setting your initial temperatures you must be careful because the support material has a lower melting point than the build material.
Either you can use a porcelain bowl like container, a hot plate, and a thermometer, or you can purchase a sonicator with heat control and a built-in digital thermometer. If you purchase the latter, remember that the sonication produces its own heat, so additional heat may or may not be necessary depending on the part size.
Post-processing is a hands-on process that involves time and attention. Depending on part size you may want to play with the temperature settings and the time you allow it to soak in VSO. You want the support material to be mushy so that you can easily remove it with a tool of your preference be careful not to destroy part surface. Remember, this process takes time, if you rush it you could sacrifice the integrity of your part.
They developed the 3D printing 3DP process in which a binder is printed onto a powder bed to form part cross sections. Contrast this concept with SLS, where a laser melts powder particles to define a part cross section. A recoating system similar to SLS machines then deposits another layer of powder, enabling the machine to print binder to define the next cross section.
Three- dimensional printing, or 3DP, is an MIT-licensed process, whereby liquid binder is jetted onto a powder media using ink jets to "print" a physical part from computer aided design CAD data. The relatively inexpensive Z is directed toward building concept-verification models primarily, as the dimensional accuracy and surface roughness of the parts are less than higher end systems.
The initial powder used was starch based and the binder was water based, however now the most commonly used powder is a new gypsum based material with a new binder system as well. Models are built up from bottom to top with layers of the starch powder and binder printed in the shape of the cross sections of the part.
The resulting porous model is then infiltrated with wax or another hardener to give the part dexterity. A wide range of polymer, metal, and ceramic materials have been processed in this manner.
The overall size of the modeller is approximately 3' X 4', so it can fit in a fairly confined area. Parts built with the starch material can be hardened to fit the application necessary. Wax infiltration gives the parts some strength but also leaves them usable as investment casting patterns. Stronger infiltrants, such as cyanoacrylate, can be used to provide a durable part that can survive significant handling.
Since the starting point of this writing, Z Corp has advanced their 3DP system in several ways. First, they released updated print cartridges Type 3 that last longer along with stronger infiltrants for durable parts.
Secondly, a new material and binder system called ZP Microstone was released that provides stronger models directly from the machine with little or no postprocessing or infiltrant. Finally, an automated waxer was released that helps control the wax infiltration process if necessary. The modeler has several important components, including the following: 1.
Build and Feed Pistons: These pistons provide the build area and supply material for constructing parts. The build piston lowers as part layers are printed, while the feed piston raises to provide a layer-by-layer supply of new material.
This provides the z motion of the part build. Printer Gantry: The printer gantry provides the xy motion of the part building process. Powder Overflow System: The powder overflow system is an opening opposite the feed piston where excess powder scraped across the build piston is collected. The excess powder is pulled down into a disposable vacuum bag both by gravity and an onboard vacuum system. Sensors near the containers warn when the binder is low or the take up is too full. The Z is operated through the COM port of a PC Workstation not included , although the system has an onboard computer that can be used for diagnostics if necessary.
Z Corp also sells a postprocessing package necessary for detail finishing and strengthening of the parts produced by 3DP. The package includes a glove box with air compressor and air brushes for excess powder removal, a heating oven to raise the temperature of the parts above that of the wax infiltrant and a wax-dipping unit that melts the wax and provides a dipping area for the parts.
Since the parts are built in a powder bed, no support structures are necessary for overhanging surfaces, unlike most other RP systems. When a file is first imported into the software, it is automatically placed in an orientation with the shortest -z height.
This is done as the fastest build capability, like other RP systems, is in the -x, -y direction. The part can be manually reoriented if necessary for best-part appearance. Multiple STL files can be imported to build various parts at the same time for maximum efficiency. The default slice thickness is 0. Objects can be copied, scaled, rotated or moved for optimum part build.
Parts can also be justified to either side of the build envelope, be it front, back, left, right, top, or bottom, with a simple menu command. Parts are copied simply by highlighting the part and clicking one copy command. The new part is automatically placed beside the current part if there is room in the build envelope; otherwise it is placed above it.
Since the build envelope is a powder bed, three-dimensional nesting can be accomplished so that parts can be built in floating space to make room for others. This 3D nesting capability is only available in a few other RP systems, and provides for a higher throughput of parts to be accomplished.
After the STL is imported and placed, a "3D Print" command is issued and the part file is sent to the machine to build. During the build, a progress bar shows the percentage of the part building, as well as the starting time and the estimated completion time. Because the material is adhesive bonded, where in SLS, the material is taken to fusion bonding. Postprocessing: Other than the Z system itself, there are several components needed for postprocessing of the part.
For a concept model, the starch parts are generally infiltrated with paraffin wax, although more durable materials are available, from plastics to cyanoacrylate. The following are the postprocessing steps for a part to be infiltrated with wax, with a total process time of about 15 to 20 minutes.
Powder Removal: After the parts are taken from the machine, the excess powder must be removed. With the system comes a small glove box with an airbrush system inside. The airbrush is used to easily and gently blow the powder off the part, and a vacuum cleaner is hooked to the glove box to remove the powder as it is blown from the part. Heat for Infiltration: Once the powder is removed from the part surfaces, the part is placed in a small oven and heated to a temperature just above that of the infiltrant wax, to provide a wicking characteristic as opposed to coating.
Infiltration: Immediately after the part is heated, it is dipped for a few seconds into a vat of molten wax, then removed and placed on a sheet to dry. After drying the part is complete. Nonetheless, it is still minimal compared to some other RP processes. Typical Uses of Z Parts Parts built with the Z system are directly intended for use as concept- verification models in a design environment. The nontoxic materials allow for the models to be safely handled in meetings or the office, directly after fabrication.
Another application that is beginning to be explored, not unlike other RP systems, is the use of Z parts for investment or sandcast patterns. The starch-based material burns out of an investment shell readily, therefore providing a quick way to produce metal hardware for testing or analysis.
With an average build time of one vertical inch per hour, even a part several inches tall can be built within a normal work day. This is extremely advantageous to any company where time is a factor in sales or production. The key disadvantages of the system include rough part surfaces, which can be remedied with sanding, and the cleanliness problems faced when dealing with any system that uses a powder as a build material or operating medium.
Also, the ink- jet cartridges must be replaced quite frequently, on the order of every hours of operation, so users must understand that the jets are expendable items just as the build powder itself. Finally, these concept models aren't fabricated to high dimensional tolerances, which may hinder the building of complex assembly prototypes. The current line of Genisys systems are small, compact table-top rapid prototyping RP machines that deliver single- material capability, and interoffice network queues for operation much like a printer.
History of the System Not unlike most newly developed technologies, the original Genisys machines had small quirks and technicalities that prevented it from really being a true "trouble free" office modeller. However, after analyzing and working with customers, most of the systems were recalled and refurbished to correct the problems.
The new line of Genisys, the Xs, apparently has printer-like reliability and operation, providing concept-modelling capability to the office environment as intended. With simple point-and-click part- building features, the software automatically places, slices, generates supports, and then downloads the part file to the network queue to be fabricated.
Parts can be set to be scaled automatically as well, although there is a manual scaling feature. Multiple parts may be nested in the -x, -y plane, again with single-click operability. Build Material The current build material is quoted as a "durable polyester". Since the systems have only one extrusion tip, the support structures are built of the same material, requiring mechanical removal upon completion of the part.
Hardware: The Genisys has a maximum build capacity of 12" X 8" x 8", whereas the entire system occupies a space of only 36" x 32" x 29". The unit weighs in at about pounds and can operate on standard house current of to Volts AC. The polyester material comes stock in the form of wafers, which are loaded into a bank of cartridges within the machine.
One wafer is loaded into the deposition head, where it is melted and deposited in thin layers through a single extrusion tip while tracing the cross section of the part being built. Once the wafer in the head is spent, it is replaced by another automatically and the build resumes. However, as with all RP devices, various users have progressed the use of Genisys models into analysis, direct use, even low- impact wind-tunnel modelling.
The material is said to be suitable for painting, drilling, and bonding to create the necessary appearance for an application. Advantages and Disadvantages of Genisys The advantages of the Genisys system include the ease of use and the network operability.
Since the preprocessing is kept to a minimum, and the systems can be networked much like printers, the Genisys lends itself to the office modelling environment.
Perhaps the major disadvantage of the system would be its single- material capacity, which results in more difficult support removal on complex parts. This situation may well be addressed in the future, similar to what was done in the progression of its sister technology of fused deposition modelling, however the vendor has no plans released at the time of this writing. The printer, which uses nozzles, jets a proprietary photopolymer developed in-house by Objet.
Because it requires no postcure or postprocessing, Quadra touts the fastest start-to-finish process of any RP machine currently on the market. Objet will initially offer one grade of material with properties similar to multipurpose resins currently offered with competitive RP systems. Additional materials with varying properties are under development. Material is delivered by a sealed cartridge that is easily installed and replaced.
Jetting of different resins, once they become available, will not require costly investments in materials or hardware upgrades. A new cartridge is dropped into place without any complicated procedures or specially trained staff. Quadra deposits a second material that is jetted to support models containing complicated geometry, such as overhangs and undercuts. The support material is easily removed by hand after building the model.
The support material separates easily from the model body without leaving any contact points or blemishes to the model. No special staff or training are required. Furthermore, models built on the system do not require sanding or smoothing where the supports are attached. The material properties of items printed on Quadra are unmatched by machines in its class and price category, and are equalled only by industrial systems that cost an order of magnitude more.
The Quadra prints in a resolution of dpi, with a layer thickness of 20 microns, and builds parts up to a maximum size of 11" x 12" x 8". The introduction of Quadra marks the start of a revolution in the area of three-dimensional imaging. An intuitive user interface aids users in setting up the build, scaling, and positioning single and multiple models. Maintenance costs for Quadra are expected to be low. Users can easily replace the lamps themselves. Important questions: 1. What is concept modelling?
Explain the applications of RP components from concept modeling. With a neat sketch , explain the following concept modeling technique a. Write a short note on Thermal jet printer? Write a short note on Genisys Xs printer HP system. Soft Tooling: It can be used to intake multiple wax or plastic parts using conventional injection moulding techniques. It produces short term production patterns. Injected wax patterns can be used to produce castings. Soft tools can usually be fabricated for ten times less than a machine tool.
Hard Tooling: Patterns are fabricated by machining either tool steel or aluminum into the negative shape of the desired component. Steel tools are very expensive yet typically last indefinitely building millions of parts in a mass production environment. Aluminum tools are less expensive than steel and are used for lower production quantities. Indirect Rapid Tooling: As RP is becoming more mature, material properties, accuracy, cost and lead time are improving to permitting to be employed for production of tools.
Indirect RT methods are called indirect because they use RP pattern obtained by appropriate RP technique as a model for mould and die making. Role of Indirect methods in tool production: RP technologies offer the capabilities of rapid production of 3D solid objects directly from CAD.
Instead of several weeks, a prototype can be completed in a few days or even a few hours. Unfortunately with RP techniques, there is only a limited range of materials from which prototypes can be made. With increase in accuracy of RP techniques, numerous processes have been developed for producing tooling from RP masters.
The most widely used indirect RT methods are to use RP masters to make silicon room temperature vulcanizing moulds for plastic parts and as sacrificial models or investment casting of metal parts. These processes are usually known as Soft Tooling Techniques. Silicon Rubber Tooling: It is a soft tooling technique.
It is a indirect rapid tooling method. Another root for soft tooling is to use RP model as a pattern for silicon rubber mould which can then in turn be injected several times. Room Temperature Vulcanization Silicones are preferable as they do not require special curing equipment. This rubber moulding technique is a flexible mould that can be peeled away from more implicate patterns as suppose to former mould materials.
There are as many or more techniques for silicon moulding as there are RP processes but the following is the general description for making simple two piece moulds.
First an RP process is used to fabricate the pattern. Next the pattern is fixture into a holding cell or box and coated with a special release agent a wax based cerosal or a petroleum jelly mixture to prevent it from sticking to the silicon. The silicon rubber typically in a two part mix is then blended, vacuumed to remove air packets and poured into the box around the pattern until the pattern is completely encapsulated. After the rubber is fully cured which usually takes 12 to 24 hours the box is removed and the mould is cut into two not necessarily in halves along a pre determined parting line.
At this point, the original pattern is pulled from the silicon mould which can be placed back together and repeatedly filled with hot wax or plastic to fabricate multiple patterns. Therefore the final part materials must be poured into the mould each cycle.
Wire Arc Spray: These are the thermal metal deposition techniques such as wire arc spray and vacuum plasma deposition. These are been developed to coat low temperature substrates with metallic materials. This results in a range of low cost tools that can provide varying degrees of durability under injection pressures. The concept is to first deploy a high temperature, high hardness shell material to an RP pattern and then backfill the remainder of the two shell with inexpensive low strength, low temperature materials on tooling channels.
This provides a hard durable face that will endure the forces on temperature of injection moulding and a soft banking that can be worked for optimal thermal conductivity and heat transfer from the body. In Wire Arc Spray, the metal to be deposited comes in filament form. Two filaments are fed into the device, one is positively charged and the other is negatively charged until they meet and create an electric arc.
This arc melts the metal filaments while simultaneously a high velocity gas flows through the arc zone and propels the atomized metal particles on to the RP pattern. The spray pattern is either controlled manually or automatically by robotic control. Metal can be applied in successive thin coats to very low temperature of RP patterns without deformation of geometry. Current wire arc technologies are limited to low temperature materials, however as well as to metals available in filament form.
Vacuum Plasma Spray technologies are more suited in higher melting temperature metals. The deposition material in this case comes in powder form which is then melted, accelerated and deposited by plasma generated under vacuum. Screw gauges and runners can be added or cut later on once the mould is finished. The exposed surface of the model is coated with a release agent and epoxy is poured over the model. Once the epoxy is cured the assembly is inverted and the parting line block is removed leaving the pattern embedded in the side of the tool just cast.
Another frame is constructed and epoxy is poured to form the other side of the tool. Then the second side of the tool is cured. The two halves of the tool are separated and the pattern is removed. Another approach known as soft surface rapid tool involves machining an oversized cavity in an Aluminum plate.
The offset allows for introduction of casting material which may be poured into the cavity after suspending the model in its desired position and orientation.
Some machining is required for this method and this can increase the mould building time but the advantage is that the thermal conductivity is better than for all epoxy models. Fig: Soft Surface Unfortunately epoxy curing is an exothermic reaction and it is not always possible directly to cast epoxy around a RP model without damaging it.
A loss of accuracy occurs during this succession of reproduction steps. An alternative process is to build an RP mould as a master so that only a single silicon RTV reproduction step is needed because epoxy tooling requires no special skill or equipment.
It is one of the cheapest techniques available. It is also one of the quickest. Several hundred parts can be moulded in almost any common casting plastic material. Epoxy Tools have the following limitations. This process converts RP master patterns into production tool inserts with very good definition and surface finish.
The production of inserts including the 3D Keltool process involves the following steps 1 Fabricating the master patterns of core and cavity. Metal mixture is powdered steel, tungsten carbide and polymer binder with particle sizes of around 5 mm. Green parts are powdered metal held together by polymer binder.
Sterlite of A6 composite tool steel. The material properties allow the inserts using this process to withstand more than 10lakh mould cycles. Direct Tooling: Indirect methods for tool production necessitate a minimum of one intermediate replication process.
This might result in a loss of accuracy and to increase the time for building the tool. To overcome some of the drawbacks of indirect method, new rapid tooling methods have come into existence that allow injection moulding and die casting inserts to be built directly from 3D CAD models.
Specific rules apply to the production of this type of injection moulds. The procedure detailed in is outlined below. Using a 3D CAD package, the injection mould is drawn.
Runners, fan gates, ejector pins and clearance holes are added and mould is shelled to a recommended thickness of 1. The mould is then built using accurate clear epoxy solid style on a Stereolithography machine. The supports are subsequently removed and the mould is polished in the direction of draw to facilitate part release. The thermal conductivity of SLA resin is about times lower than that of conventional tool steels. The cooling of the mould is completed by blowing air on the mould faces as they separate after the injection moulding operation.
Injection cycle time is long. Both resistance to erosion and thermal conductivity of D-AIM tools can be increased by deposition of a 25micron layer of copper on mould surfaces. Important Questions: 1.
What is rapid tooling? Compare rapid tooling with conventional tooling. Write a short notes on indirect rapid tooling? Write a short notes on silicon rubber tooling? Write a short notes on aluminium filled epoxy tooling? Write a short notes on spray metal tooling? Holes in the bottom of the part allow uncured resin to drain from the part. The net result is QuickCast patterns in as little as 2 to 4 days and quality metal castings in 1 to 4 weeks. It will burn out in the investment casting process with very little residue.
The pattern is leak tested to make sure it is air tight. QuickCast pattern is given to the caster. Caster puts part through ceramic coating process and performs firing procedure to burn out SLA pattern. Copper polyamide: The Copper Polyamide tooling process from DTM Austin, Texas involves the selective laser sintering of a copper and polyamide powder matrix to form a tool.
All of the sintering is between the polyamide powder particles. The process boasts an increase in tool toughness and heat transfer over some of the other soft tooling methods. These characteristics are provided by the copper and can give the user the benefits of running a tool with pressure and temperature settings that are closer to production settings. The primary disadvantage is the low material strength.
With DMLS, metal powder 20 micron diameter , free of binder or fluxing agent, is completely melted by the scanning of a high power laser beam to build the part with properties of the original material.
An additional benefit of the DMLS process compared to SLS is higher detail resolution due to the use of thinner layers, enabled by a smaller powder diameter. This capability allows for more intricate part shapes. Material options that are currently offered include alloy steel, stainless steel, tool steel, aluminum, bronze, cobalt-chrome, and titanium.
In addition to functional prototypes, DMLS is often used to produce rapid tooling, medical implants, and aerospace parts for high heat applications. The DMLS process can be performed by two different methods, powder deposition and powder bed, which differ in the way each layer of powder is applied.
In the powder deposition method, the metal powder is contained in a hopper that melts the powder and deposits a thin layer onto the build platform. In the powder bed method shown below , the powder dispenser piston raises the powder supply and then a recoater arm distributes a layer of powder onto the powder bed.
A laser then sinters the layer of powder metal. In both methods, after a layer is built the build piston lowers the build platform and the next layer of powder is applied. The powder deposition method offers the advantage of using more than one material, each in its own hopper.
The powder bed method is limited to only one material but offers faster build speeds. Two materials are available for the DMLS process: 1 bronzebased materials, which are used for injection molding of up to 1, parts in a variety of materials, and 2 steel-based material, which is useful for up to , plastic injection molded parts.
This process was used to produce injection mold tooling for a Germany appliance manufacturer. Seven mold inserts were produced in 20 hours using the bronze-based material. Several thousand molded parts were produced in 30 percent glass-filled polyamide. Also, the steel material builds slowly. The machine is capable of creating steel parts up to 12 x 12 x 10 inches x x mm in size.
ProMetal applications include tooling for plastic injection molding, vacuum forming, blow molding, lost foam patterns and the direct fabrication of powder metal components. Motorola joined a collaborative effort consisting of several industrial members, all part of MIT's Three Dimensional Printing Consortium. Although early reliability problems delayed the implementation effort, recent advances have provided acceptable results.
The figure 9. The life of the silicone rubber mould is about epoxy or PU parts. The PU and epoxy parts can be used for sand casting. Laminated tooling is an alternative to building cavities directly on an RP machine. Laser cutting or water jet technologies generally produce the profiles.
Further work is planned to examine the use of variable laminate thicknesses, as well as cost and time predictors and different bonding methods. Thomas Himmer of the Fraunhofer Institute for Material and Beam Technology, in Dresden, Germany, continues to work with laminate tooling, particularly looking at new applications for the automotive and aircraft industries.
The process specifically involves the laser cutting of laminates that are joined together before being CNC machined to provide an improved surface finish. Loughborough University is continuing to investigate the use of laminate tooling for the molding of polyurethane foam. Research is underway to control tool temperatures more accurately using conformal-heating channels. The aim of the work is to improve the flow properties of the foam to allow thinner mold sections.
The researchers are investigating whether better temperature control will allow the foam to expand further and into thinner sections. Currently, a thickness of less than 5 mm 0. To produce a mold tool, the CAD model must take the form of the required cavity.
By cutting all of the slices of the cavity in sheet metal, a stack of laminates can be made to replicate the original CAD model. Using either clamping or diffusion bonding, it is possible to create a pseudo-solid cavity in hardened tool steel without the need for complex post process cutter path planning.
Due to the use of relatively thick laminates - typically 0. Research also is being performed into the use of laminate tools in pressure die-casting. Tool life is a function of the initial sheet material, which can be hardened after cutting and lamination.
However, part complexity is bounded by layer thickness. One significant advantage of laminated tooling is the ability to change the design of parts quickly by the replacement of laminates if un-bonded. Conformal cooling channels also are easily incorporated within the tool design and laminated tooling is good for large tools as well.
The need for finish machining to remove the stair steps is the main disadvantage of this process. Delivery of first article samples, 4 weeks very simple parts — 12 weeks normal complexity — longer for complex or parts requiring ceramic core tooling Delivery of production, 2 — 12 weeks after First Article approval.
Highest tooling expense Lowest investment casting pattern cost Hard tooling will have the longest life. Simple tooling will last for hundreds of thousands of parts. Complex tooling with slides and cores will wear over time but can generally be refurbished. This is not normally necessary for many years. Yields the best surface finish and most consistent dimensional control. Next a form is built around the master pattern and silicone is poured in, encasing the pattern.
After the silicone is cured the pattern is removed and the mold is ready for production. The urethane of choice is then colour matched and injected into the mold. After the urethane cures the part is removed from the mold, checked for quality and accuracy, then post cured for optimum mechanical properties. Delivery of first article samples, 3 — 6 weeks Delivery of production, 2 — 12 weeks after First article approval Soft tooling is less costly than Hard Tooling Pattern cost is higher than Hard Tooling.
This is because the tooling will cycle slower due to the poor thermal conductivity of mold material Life of soft tooling is limited. Life will depend upon the complexity of part. The more complex the shorter the life Surface finish and dimensional control is not as good as Hard Tooling A single SLA stereolithography or Objet pattern is generally used to make the tooling Patterns made from individually produced patterns Each casting produced will require one pattern.
But it is becoming more and more popular to use as the fastest way to produce investment castings where design changes or unknown future requirements allow for higher per piece pricing since no tooling expense will be incurred. Some information about suitable investment casting patterns is in order. To produce investment castings it is necessary to shell the pattern. This involves coating the pattern with a ceramic material.
After shelling, the pattern must be removed from the shell. This produces a void in the shell which will be the receptacle for the molten metal. When the pattern is removed from the shell it must be removed completely and without damaging the shell. Wax is a foundry friendly pattern material.
The wax is removed from shell by heating. This is generally done in an autoclave very quickly. As the shell heats up the wax in immediate contact with the shell quickly changes state from solid to liquid and is absorbed into the porous shell thus allowing room for the balance of pattern wax to heat up, expand and be drained.
Some of the RP, rapid prototype, patterns do not melt and must be burned out of shell. Unfortunately some also expand and can severely crack the shell if not hollow. Dimensionally of lower quality than SLA patterns. Objet Highest quality RP, rapid prototype, patterns from dimensional and surface finish point of view.
Patterns must be hollowed out. Least consistent dimensional stability of all RP, rapid prototype, patterns; least costly of all RP, rapid prototype patterns. The most important thing to remember is to get the foundry involved in your design early to allow the foundry to give advice on how to make the part friendlier for investment casting. This file format is supported by many other software packages; it is widely used for rapid prototyping and computer-aided manufacturing.
STL files describe only the surface geometry of a three dimensional object without any representation of colour, texture or other common CAD model attributes. Binary files are more common, since they are more compact. An STL file describes a raw unstructured triangulated surface by the unit normal and vertices ordered by the right-hand rule of the triangles using a three-dimensional Cartesian coordinate system.
This format has long been the industry standard in rapid prototyping. A polygon is defined as a flat shape which is bounded by a closed circuit. Each polygon with n sides can be represented using n-2 triangles. Each one of those sides is a square, meaning it can be represented using 12 triangles.
Since we are dealing with 3-dimensional shapes, each triangle has a direction. This direction is expressed by the normal of the triangle. STL manipulation solutions allow: 1. Fixing those models in order to produce watertight models see below for explanation 2.
Additionally, most vendors offer several packages. Please consult your local distributor for pricing. Some vendors offer free automatic service, while some will have a specialist look into more complex issues. Pricing if applicable is typically per use, greatly reducing the initial cost. This means we will need to fix the file in order to print it using an Objet 3D printer. We will discuss later on this document on how this can be achieved.
Zero thickness: Since files printed on Objet printers have to be fabricated in real world. The files have to have a volume which is larger than zero. Sometimes, a model is represented on the CAD software using just a 2D model, which has no volume: The part shown above is a sheet of material which has no volume, Though it is three dimensional! We distinct between two cases of bad edges: Near bad edges: Near bad edges are defined as edges which have a neighbour triangle which is closer than a set threshold.
Those are usually closed automatically using your software of choice. This is slightly more complex, as it might cause a case of zero thickness. The part above has a real bad edge in one of his faces. Since Objet printers require a positive thickness in order for a file to be printable, this will require one of two solutions: a. Close the hole Once the user closes adds triangles to the hole, the model is once again watertight and has a positive volume. Once again, it is printable. Create thickness If the design intent was to create a box with one missing face, the user would need to create thickness, making the part printable.
The catch is that the output process involves a configuration step, and the quality of the final RP part is dependent upon a proper configuration. The STL file is intended to simplify the complex mathematical descriptions of surface and solid geometry into a form that can be readily used to drive the imaging systems of RP machines.
If any three points are chosen from a 3-dimensional surface then a triangle can be described by those points to approximate a portion of that surface. Of course, a triangle is by definition flat — lacking any curvature whatsoever — so if the surface in question contains any curvature then there is some error, or deviation, in the approximation.
However, if the triangle size is reduced to the point where it is much smaller than any curvature in the surface, then the deviation can be brought down to a level where it is negligible.
What is the limit to such a reduction? There is a practical limit — as the triangles decrease to an infinitesimally small size, the number of them required to complete the surface becomes infinitely large, as does the size of the final STL file. Most configuration settings for outputting STL files are aimed at this very issue — how small to make the triangles to best approximate the surface geometry while not making enormous file sizes. This knowledge base article will attempt to give you the tools you need to understand this configuration process, and visualize the outcome of the final part.
Armed with this information, you can use the help function for the CAD software that you use, and develop an approximation that works for your needs. The major CAD software programs such as ProEngineer and SolidWorks actually show you an image of the faceted STL file so that you can see for yourself how closely the triangles approximate your geometry. The proof is in the pudding, so to speak, so we recommend installing a file viewer for STL files just to be sure.
Doing so, you can rotate, zoom, pan and cross-section the file to be sure that it is true to form. Here are links to some good STL viewers that are free to install and use. We know that in the long run you need to succeed for us to succeed. Magics rapid prototyping software enables you to import a wide variety of CAD formats and to export STL files ready for rapid prototyping, tooling and manufacturing.
Its applications include repairing and optimizing 3D models; analyzing parts; making process-related design changes on your STL files; designing fixtures; documenting your projects; production planning and much more.
Healthcare organizations worldwide increasingly rely on 3D anatomical models for pre-operative planning, specialist consultation, implant fit and design, patient counselling and medical education. Includes an extensive help function and templates. Annotate Add 2D and 3D annotations, shapes, text and bitmaps.
Measure Easily create 2D drawings from 3D files. Extensive feature recognition allows measuring of distances, radii and angles in 3D. Add tolerances and additional info. Present Make a 3D slide show with adjustable colours, shading and transparency. Write a short note on STL files? Write a short note on solid view?
Write a short note on magics? Write a short note on mimics? Write a short note on magic communicator? Write a short note on internet based software? Write a short note on collaboration tools? Explain the procedure of modeling.
SH file creation and layering steps before printing 3D model in RP machine for the following types of models i. Economical model. Precision model. Nuisance parameters include age of the laser, beam position accuracy, humidity and temperature, which are not controlled in the experimental analysis but may have some effect on a part.
Constant parameters include beam diameter, laser focus and material properties, etc. These include layer thickness, hatch space, scan pattern, part orientation, shrinkage of the material and beamwidth compensation, etc. Layer thickness , hatch space, part orientation and depth of cure are the most vital among the control parameters. Identification of requirements and key manufacturing parameters: The functional requirements of a manufacturing process include accuracy, strength, buildtime and efficiency of the process.
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