PAPER PRESENTATION ONRAPID PROTOTYPING

PRESENTING BY A.V.SUDARSHAN B.DEVI SAI KIRAN 10731A0301 10731A0304 3RD MECH 3RD MECH

Email: sudarshan3209@gmail.com

FROM,

PBR VITS,

KAVALI.

Rapid prototypingINTRODUCTION

Rapid prototyping is the automatic construction of physical objects using additive manufacturing technology. The first techniques for rapid prototyping became available in the late 1980s and were used to produce models and prototype parts. Today, they are used for a much wider range of applications and are even used to manufacture production-quality parts in relatively small numbers. Some sculptors use the technology to produce exhibitions.

The use of additive manufacturing for rapid prototyping takes virtual designs from computer aided design (CAD) or animation modeling software, transforms them into thin, virtual, horizontal cross-sections and then creates successive layers until the model is complete. It is a WYSIWYG process where the virtual model and the physical model are almost identical.

With additive manufacturing, the machine reads in data from a CAD drawing and lays down successive layers of liquid, powder, or sheet material, and in this way builds up the model from a series of cross sections. These layers, which correspond to the virtual cross section from the CAD model, are joined together or fused automatically to create the final shape. The primary advantage to additive fabrication is its ability to create almost any shape or geometric feature.

The standard data interface between CAD software and the machines is the STL file format. An STL file approximates the shape of a part or assembly using triangular facets. Smaller facets produce a higher quality surface.

The word "rapid" is relative: construction of a model with contemporary methods can take from several hours to several days, depending on the method used and the size and complexity of the model. Additive systems for rapid prototyping can typically produce models in a few hours,

although it can vary widely depending on the type of machine being used and the size and number of models being produced simultaneously.

Some solid freeform fabrication techniques use two materials in the course of constructing parts. The first material is the part material and the second is the support material (to support overhanging features during construction). The support material is later removed by heat or dissolved away with a solvent or water.

Traditional injection molding can be less expensive for manufacturing polymer products in high quantities, but additive fabrication can be faster and less expensive when producing relatively small quantities of parts. 3D printers give designers and concept development teams the ability to produce parts and concept models using a desktop size printer.

Rapid prototyping is now entering the field of rapid manufacturing and it is believed by many experts that this is a "next level" technology.

Prototyping technologies Base materials ;Selective laser sintering (SLS) Thermoplastics, metals powders ;Direct Metal Laser Sintering (DMLS) Almost any alloy metal; Fused deposition modeling (FDM) Thermoplastics, eutectic metals; Stereolithography (SLA) photopolymer; Laminated object manufacturing (LOM) Paper ;Electron beam melting (EBM) Titanium alloys ;3D printing (3DP) Various materials.

An increase in usability generally positively affects several facets of a company’s output quality. In particular, the benefits fall into several common areas:

Increased productivity Decreased training and support costs Increased sales and revenues Reduced development time and costs Reduced maintenance costs Increased customer satisfaction

Stereolithography (SLA) Stereolithography uses UV ray to solidify liquid acrylic polymer layer by layer on a moving platform and after many layers, the prototype in the preferred form is formed. This process is carried on in a VAT, a device that is filling up with photocurable liquid acrylate polymer. Stereolithography is one of the most used forms of rapid prototyping because of accuracy (Tolerances= 0.0125mm), less time taken (depends upon the size and complication of the part) and where parts details are fine and their geometry is to difficult to machined.

Metal Prototypes, Metal Rapid Prototyping 

ProtoCAM offers quick turnaround metal prototypes and rapid prototyping for metal parts.  Depending on material, timing requirements, critical dimensions and post-machining operations, there are several different methods that can be used to satisfy your metal prototyping requirements.  Selective laser sintering (SLS), investment castings, plaster castings, sand castings and CNC machining are the most common methods to manufacture rapid metal prototypes.

Selective Laser Sintering (SLS)

SLS is an additive rapid prototyping process that utilizes an A6 metal to build the rapid metal prototype up in very thin layers.  Minimum wall thickness is .040”.  A6 is also referred to as tool steel or high carbon steel.

Investment Casting

Investment casting is a metal casting process that uses a master pattern to create a ceramic mold.  Typical metals used are carbon steel, stainless steel, aluminum, and bronze alloys.

One type of master pattern used in an SLA Quick Cast pattern.  Using the Quick Cast pattern eliminates the need of tooling to create the wax pattern.  Not only is cost greatly reduced, so is the lead time to produce the metal prototype.  The SLA Quick Cast investment casting method is great for a some metal prototypes; contact ProtoCAM for details.  Using the quick cast method, metal prototypes can be produce in as little as 2 weeks.

Wax patterns are also used when creating the ceramic mold for the investment casting method.  Wax patterns offer superior surface finish, and work well for rapid metal prototyping applications that require a higher quantity (hundreds or more).  Wax patterns can be quickly produced using silicone rubber molds. 

Plaster Cast Metal Parts

Plaster casting is typically the best way to produce metal prototypes that will be die cast production parts.  An SLA master pattern is used to create the plaster cast mold.  Plaster cast metal prototypes offer improved surface finish when compared to the sand casting method.  Aluminum and zinc alloy plaster cast metal parts can be produced in about 2 weeks.

Sand Castings

Sand casting is an economical way to produce metal prototypes.  The process is similar to the plaster cast method, but surface finish is rough.  Typical metals used in sand casting are iron, aluminum and zinc alloys.

Rapid Prototype Aluminum Castings, Steel Castings, and Stainless Steel Castings

The most common type of metal prototyping is aluminum casting.  Rapid prototype aluminum castings can be created using investment casting, sand casting or plaster casting.  ProtoCAM also does many steel and stainless steel rapid prototypes in addition to rapid aluminum prototyping.

Metal Coated Prototypes

ProtoCAM does metal coating on plastic prototypes created from other rapid prototyping techniques such as SLA, urethane casting, and injection molding.  Typical metal coated prototypes are plated with nickel, copper, and chrome.

Benefits of Creating Metal Prototypes

Quickly evaluate metal part design Produce metal prototypes in almost any metal material Allow testing of the part in the actual production materials Produce metal parts without expensive tooling

ProtoCasting From RapidProtoCasting ®

ProtoCasting- From CAD to fully functional high-strength metal parts in days!

rapid prototyping + precision investment casting = protocasting

Rapid prototype castings in high strength titanium, copper, stainless steel, Inconel and cobalt chromium alloys from RapidProtoCasting. Our rapid investment casting process combines:

A quick manufacturing facility coupling rapid prototyping and rapid investment casting (protocasting) and designed for high mix/low volume complex precision superalloy casting production.

Prototyping and protocasting processes capable of consistently delivering low volume high quality metal parts within days of receiving a customer CAD model.

Skilled personnel able to fabricate, finish and inspect high-quality metal castings to demanding industry specifications and proprietary customer requirements.

RAPID MANUFACTURING RapidProtoCasting delivers precision castings from in-stock alloys in as short as one day after receipt of a rapid prototype pattern and as little as four days after receipt of a casting CAD solid model.

RAPID INVESTMENT CASTING Custom designed purpose-built equipment delivers the highest quality engineered precision prototype castings and production castings. Advanced equipment designs ensure the precise investment ceramics processing and vacuum induction melting and casting necessary for today's high-strength copper, stainless steel, nickel, cobalt chromium and titanium superalloy castings.

PROTOCASTING RapidProtoCasting combines the most advanced industry ceramics with proprietary investment casting processes to deliver complex precision castings within days of receiving a new customer design. From CAD model to lost wax investment casting to final inspection, RapidProtoCasting's rapid manufacturing delivers prototype castings with production

quality in days.

How does Rapid Prototyping Work?

Rapid prototyping is a technology that takes a three-dimensional computer model and builds a three dimensional part by building layers upon layer of material. Its speed and low cost allow design teams to confirm their new designs early and frequently in the process.

Start with a 3 dimension computer model. Typically created in 3D CAD products like SolidWorks. From 3D CAD, an STL file is exported. Typically done as a "File Save As …". Xpress3D CAD Add-ins perform this step automatically. The STL file is then translated into hundreds (or even thousands) of cross sectional data. Starting with the bottom slice, the prototyping machine builds each slice upon the previous, until all the slices are built and the prototype is complete.

Rapid prototyping isn't a solution to every part fabrication problem. After all, CNC technology is economical, widely understood and available, offers wide material selection and excellent accuracy. However, if the requirement involves producing a part or object of even moderately complex geometry, and doing so quickly - additive technologies have the advantage. It's very easy to look at extreme cases and make a determination of which technology route to pursue, CNC or

RP. For many other less extreme cases the selection crossover line is hazy, moves all the time, and depends on a number of variably-weighted, case-dependent factors. While the accuracy of additive methods isn't generally as good as CNC, it's adequate today for a wide range of exacting applications.

The materials used in rapid prototyping are limited and dependent on the method chosen. However, the range and properties available are growing quickly. Numerous plastics, ceramics, metals ranging from stainless steel to titanium, and wood-like paper are available. At any rate, numerous secondary processes are available to convert patterns made in a rapid prototyping process to final materials or tools.

Rapid Prototype Machine

Z Corporation rapid prototype machines create 3D physical models faster and cheaper than any other rapid prototyping machine

Since rapid prototype machines were introduced in the 1980s, the meaning of the word "rapid" has been somewhat relative. Creating a 3D prototype model from 3D or other digital data can take days, if not weeks depending on the type of rapid prototyping machine used.

Z Corporation 3D printers make rapid tooling and prototyping truly fast, bringing the benefits of rapid prototyping to prototype manufacturers and companies seeking to bring this capability in-house. These rapid prototype machines, which include the entry-level ZPrinter 310 Plus, the automated ZPrinter 450, and the top-of-the-line Spectrum Z510 are fast and versatile, allowing engineers and product designers to make their vision a reality in a fraction of the time and cost of other rapid prototype machines.

With Z Corporation's inkjet 3DP (three-dimensional printing) system, those engaged in rapid product development and rapid prototyping and manufacturing applications can discuss a project in the morning and see

an actual 3D scale model in the afternoon. No other rapid prototype machine builds parts as fast.

Z Corporation's 3D rapid prototype machines are fast and cost-effective enough for design engineers to build multiple prototypes throughout the concept modeling and testing stages of development. In the past many companies could afford to make only one prototype just prior to tooling investments.

Z Corp rapid prototype machines provide the ability to:

Identify problems early. Parts printed on Z Corp. rapid prototype machines provide a fast and efficient way to easily identify design issues and challenges.

Communicate more effectively. Functional prototype models are useful for troubleshooting design issues and reaching agreement on design direction

Streamline internal communication. Z Corp. printers make it easy to produce prototypes in volume for review by a variety of functional teams within an organization.

Perform iterative design. Z Corp. 3D printers make it quick and affordable to output presentation prototype models throughout the design process.

Applications

*Tooling

*Industries

*Biological,Biomedical and Chemistry

*Aerospace

*Marine

*Automotive

*Construction

*Military Weapons and Parts

*Medical

*Electronics.

Advantages of prototyping

May provide the proof of concept necessary to attract funding Early visibility of the prototype gives users an idea of what the

final system looks like Encourages active participation among users and producer Enables a higher output for user Cost effective (Development costs reduced). Increases system development speed Assists to identify any problems with the efficacy of earlier design,

requirements analysis and coding activities Helps to refine the potential risks associated with the delivery of

the system being developed

Disadvantages of prototyping

Producer might produce a system inadequate for overall organization needs

User can get too involved whereas the program can not be to a high standard

Structure of system can be damaged since many changes could be made

Producer might get too attached to it (might cause legal involvement)[verification needed]

Not suitable for large applications Over long periods, can cause loss in consumer interest and

subsequent cancellation due to a lack of a market (for commercial products)

may slow the development process,if there are large number of end users to satisfy.

Conclusion:

When used as a value added custom molds component, pressure transducers can help the mold maker to gain a competitive edge. With the increase of international competition, the trend toward more sophistication will continue and the use of pressure plastic molds sensors is a good example of adding a valuable service to help the customer.

By all this considerations we can say that rapid prototyping technique is a very useful in all fields.