| 3D modelling and it's corporate big brother | | | | process developed by 3D Systems where a laser |
| of Solid Freeform Fabrication or Rapid | | | | strikes a bed of metal or plastic powder, |
| Prototyping began in the early 80's as a way | | | | fusing portions of it into the required |
| to use machines to make objects faster than a | | | | shape. The bed is lowered, more powder added, |
| traditional modeler could. By using Computer | | | | and the laser passes over it again. This |
| Aided Design machines such as pen plotters | | | | process, which is the original basis of the |
| and then variable-height plotters, developers | | | | LENS process, can be used to create both |
| soon came up with the means to have a machine | | | | fully solid or partially solid metallic or |
| able to carve elements out of foam or wood in | | | | polymer objects in a limited run |
| multiple layers or levels, but it was still | | | | environment.Stereo Lithography uses a laser |
| one half or one side. A CAD table could | | | | striking a pool of photopolymer in a pattern |
| produce an object of up to 48"x48" with a | | | | defined by the CAD or STL file data. Once the |
| depth of up to 4" - but only 1 sided, so two | | | | laser has finished it's pass, the platform |
| of them would have to be made for an 8" | | | | lowers, immersing the object under the |
| object, or many layers for a more detailed or | | | | surface of the photopolymer and the laser |
| larger object.The first Stereo-Lithography | | | | passes over again, slowly building up an |
| system was believed to have been developed at | | | | object under the polymer. BaE uses |
| Xerox labs in the mid 1980's by a team of | | | | Stereolithography to produce prototypes of |
| engineers who were experimenting with a way | | | | equipment and parts extensively.These methods |
| to fuse toner into a more solid substrate. | | | | have a very fine accuracy, ranging from |
| They realised that by using a platform that | | | | 0.01mm for laminated Object Modelling down to |
| moved only on the z axis or up and down with | | | | 0.003mm for Stereolithography. This enables |
| a scanning laser that could traverse across | | | | models and objects to be made to exacting |
| the entire plate on the x- and y- axis they | | | | specifications and allows for items such as |
| could harden a layer of waxy toner, then drop | | | | jewellery mounts to be designed and then |
| the platform down a tiny fraction, put new | | | | mass-produced in days rather than weeks.For |
| toner on, and do the process again, thus they | | | | larger objects such as columns, airplane |
| could slowly build up a form in 3 | | | | components, car body panels, statues and the |
| dimensions.Xerox was pretty creative in the | | | | like - a different method can be employed. 3D |
| 70's and 80's - In 1971, a team from Xerox | | | | routers or cutting machines have also been |
| came up with the idea of putting a printhead | | | | developed that have a cutting or routing |
| assembly and scanning laser into a | | | | blade set on a movable head that can travel |
| photocopier and created the first laser | | | | on all 3 axes and do very complex carving |
| printer. | | | | down to a resolution of around 0.1mm detail, |
| | | | depending on the cutting or routing heads.The |
| So, realising that this solid manufacturing | | | | markets for Rapid Prototyping and Rapid |
| process could be commercialised, they let the | | | | Manufacturing for hobbyists is growing. The |
| word out to manufacturers and developers who | | | | machinery ranges in price from $3,500 up to |
| could put the idea to good use.In 1988, a | | | | over $500,000 for some of the metal synthesis |
| team led by S. Scott Crump developed a | | | | equipment. This enables hobbyists and people |
| process called Fused Deposition Modelling. | | | | who need limited run products to get them at |
| They went on to form the company Stratasys | | | | a fraction of the cost of previous methods |
| and produced Rapid Prototyping machines that | | | | such as moulded casting or milling and |
| used this technology to create physical | | | | engraving prototyping.Just do a search for |
| objects from 3d models.Laminated Object | | | | Rapid Prototyping or Solid Freeform |
| Manufacturing or LOM is a process developed | | | | Fabrication - there are plenty of companies |
| and commercialized by Heliosys, in which many | | | | out here ready to build your 3d object in 3 |
| layers of laminated paper are sealed together | | | | full dimensions so you can hold it in your |
| after they have been cut into shape, creating | | | | hand.Tim Morrison is a founding member of is |
| a 3d object consisting of thousands or tens | | | | a technology company developed to bridge the |
| of thousands of sheets tightly bonded | | | | gap between virtual and real worlds in the |
| together.Laser Engineered Net Shaping or LENS | | | | realm of 3d. Our goal is to be able to |
| is a recent process developed by Sandia Labs | | | | produce a 3d image on the computer and then |
| where a laser is focussed onto a steady | | | | produce it as a physical object - no matter |
| stream of metal particles sprayed into a pool | | | | what the complexity or detail involved. In |
| of liquid metal. This process builds up a | | | | this vein, we keep track of anything in |
| fully realised object with no hollow portions | | | | relation to 3D imagery that can bring our |
| or any gaps. The metal is fully dense and the | | | | goals closer, be it gaming consoles that can |
| final part is almost as strong as a milled | | | | do more than play games, hardware imaginng |
| item. Optomec has licensed the LENS | | | | solutions, and software that can make our |
| technology into a Rapid Prototyping | | | | lives easier. |
| machine.Selective Laser Sintering or SLS is a | | | | |