3D Printing: The Revolution in Personalized Manufacturing
CHAPTER INVENTING 3D PRINTING Innovative ideas often occur to more than one person at the same time And it usually takes more than one person’s efforts to make an innovative idea a reality 3D printing got its start with Chuck Hull Scott Crump and Carl Deckard These engineers did not know one another when they each invented 3D printing but they had a lot in common They each worked in manufacturing They each saw that traditional manufacturing needed a new and faster approach to developing prototypes Prototypes are demonstration objects that resemble the final product to help developers refine a product before they build it Engineers and designers use prototyping to create a mockup of a part to see how well it will work CAD software helps engineers and designers make prototypes so they can test their designs At some point in the process designers must make and test the actual physical prototype Often building and testing a design happens many times before the designed product actually works Using traditional manufacturing approaches of building welding and assembling a prototype is costly and time consuming Hull Crump and Deckard saw the need to speed up prototyping They knew that rapid prototyping would reduce
the time and cost of developing a new product These quickly made prototypes would have enough of the features of the final product to help designers and engineers make changes to the design so they could build the best product possible Independently of one another the three men successfully developed 3D printing processes that are still in use MEET CHUCK HULL In 1983 Charles Chuck Hull had been experimenting for months with a technique called stereolithography SLA This printing method requires a computer an ultraviolet UV laser and a liquid goo called photopolymer resin The resin naturally hardens when it comes in contact with the heat of the laser’s light Hull was working for a company in San Gabriel California developing durable resin coatings for tabletops His experiments with the resin gave him the idea that he could turn his digital designs into physical objects using those same resins His company agreed to give him a small lab to see what he could make Hull imagined that he could create a process for engineers to quickly make prototypes for the objects they wanted to To be successful an invention has to be more than a good idea It has to be designed well and work well So before making a product a company will first develop a prototype above or model to make sure the idea will work as planned look good and be cost-effective to manufacture This can be a lengthy expensive process however 3D printing can speed it up significantly and save companies money too I N VE N T I N G 3D P R I N T I N G 9
manufacture After many disappointing attempts suddenly late one night he turned the goo into a cup He used software on his computer to draw the cup and he used the laser to harden the resin and to print the cup layer by layer Excitedly he called his wife Antoinette and asked her to drive to the lab to see what he had created She in her pajamas and ready for bed said This had better be good Years later when These decorative pieces are 3D printed through stereolithography This method uses photopolymer resins which harden when exposed to ultraviolet light interviewed about that moment Antoinette said He held this part in his hand and he said I did it The world as we know it will never be the same We laughed and we cried and we stayed up all night just imagining Hull started his own 3D printing company 3D Systems in 1986 He went on to receive the first patent for 3D printing using stereolithography the technology behind his cup He also received several other patents for 3D technologies and developed STL the stereolithography file format that many 3D printers use 10 3D P R IN T IN G
SLA STL AND CAD 3D PRINTING RELIES ON THESE BASIC TECHNOLOGIES STEREOLITHOGRAPHY SLA This was the first 3D printing process and continues to be widely used SLA remains popular because the technique produces a smooth object Other 3D techniques can show individual layers of material often resulting in a bumpy unfinished look In an SLA printer a UV laser is focused on a tub of UV-curable photopolymer resin to produce a layer on the build platform Then the printer lowers the build platform slightly for the next layer and the process is repeated until the object is fully formed This high-quality process comes at a high price for the printer and the resin material Originally organizations used SLA for commercial purposes only Since then companies such as Formlabs 3D Systems and others have provided desktop SLA printers at more affordable prices for individual professionals STEREOLITHOGRAPHY FILE FORMAT STL Chuck Hull developed the STL file format for his SLA files A file format stores specific types of information For example a JPEG file format contains data for displaying an image A pdf contains data for sharing a document across platforms For 3D printing Hull wanted to invent a file format that would allow a 3D printer to read a CAD file He called it STL another abbreviation for stereolithography STL has become the standard 3D printing file format COMPUTER-AIDED DESIGN CAD Engineers and designers in many fields use CAD software to create two or three dimensional 2D or 3D digital representations of physical objects on their computers They can use those designs to determine how best to build the object With 3D printing they can design the object using CAD save the information as an STL file and then print the object from a 3D printer 11
