2012年10月31日星期三

CNC In Modeling And Prototyping


CNCs in Modeling and Prototyping
A CNC tool can be used in many ways for prototyping, reverse engineering and modeling.  As a rapid-prototyping tool, a OMNI can machine foam, wood, plastics and aluminum to efficiently create prototype and reproduction parts.  With a CNC tool, you will typically be doing subtractive prototyping, but it is a process that lets you machine quickly in materials that are similar to the end product.  Large projects can also be done using additive layering techniques that allow substantial models to be constructed even beyond the machinable area of the CNC.
The sheer versatility of a CNC wood router in a prototyping setting is nothing short of astounding.  With a good CAD/CAM package and a CNC router, it is possible to create master models with the proper draft for secondary operations such as casting, vacuum forming, sheet metal stamping and FRP composite construction.  These types of models are typically 2.5D, meaning that they don’t have undercuts and can be completely machined on a 3-axis CNC on one side of the material.  In addition, advances in affordable hardware and software now give you the ability to cut double-sided parts using 3 axes and carve true 3D parts on a machine equipped with a 4th axis, rotary indexer.  The indexer can be used as a lathe to cut simple profiled turnings or elaborate 3D parts and relief carvings, giving many of the advantages of a 5-axis tool at a fraction of the cost.
Mold Making
Aside from playing a key role in subtractive methods of creating models, the CNC is also instrumental in preparing molds for creating parts.  Thermoset plastic parts can be created in conjunction with a rotational molding machine.  Masters can be created on the CNC, molded and setup to produce thin-walled and hollow models not possible using a subtractive strategy. A CNC router coupled with the proper mold making equipment is a potent combination spanning many industries and applications.
Reverse Engineering Processes
While CNC wood routers excel at producing accurate parts with speed and efficiency, they also excel when it comes to reverse engineering an existing 2D or 3D part.  The digital version of the part can then be toolpathed to produce an exact duplicate, or transformed into an updated version by modifying the scale or geometry to create the required part. Using the optional rotary indexer, odd-shaped and cylindrical 2D & 3D parts can be digitized a full 360° with the same straight-forward method as a standard 3-axis tool equipped with a probe.

没有评论:

发表评论