- Reverse Engineering -2
The aim of the process of Reverse Engineering is to use feature and shape data of one product to build another product, this data can be used with or without modification in the new product. We ultimately need to create a core and cavity of the new product, so that it can be manufactured by plastic injection moulding.
The first step is to select the product whose features are to be copied. Now, we need to gather all the dimensional data of the product by some means, and then convert it into information, which we can utilize for the process of Reverse Engineering. 3D digitizing is the process that we use for collecting dimensional data.
There are methods depending upon the product shape and complexity for example, dimensions of a simple shape such as a cylinder can be derived using a vernier caliper and height gauge. However, for a 3D shape, such as a fan blade, we need to collect a lot of information at various sections, which is not directly possible by the previous method. Hence, advanced technologies such as as 3D digitizing, Laser, Optical scanning have to be used. The data obtained is in 3D IGES, or ASCII formats comprising of X,Y,Z points or else digitizing software [Renishaw, in this case ] generates a zero cutter NC program which can be back-plotted using software like MasterCam to generate the geometry. Now that we have obtained the point cloud data of the product, the real challenge is to build a surface over these points. This calls in for the use of software tools and a very good expertise in data manipulation. The data is taken into a CAD software after translation. Now, 3D- wireframe modeling is achieved through point handling techniques. The end result of this process, going on for a couple of days, is a neatly created surface model, which fits on the 3D-wireframe skeleton. Now the CAD model replication of the component is ready. We now proceed towards creation of the punch and cavity. This is a fairly simple job for us, due to the usage of High end Software such as I-DEAS. The software allows us to generate a core and cavity along with all details such as mold cavity separation, drafts, tolerances, creation of spline curves from set of polylines, spline blendings, and flexible surface creations.
Once the moulds are ready, we proceed for generating the CNC code for both the core and cavity, to get it machined on a CNC machine. Generation of CNC programming code is achieved by us using the capabilities of mastercam software. The software checks the programs for errors, by back-plotting and solid verification thus, there is no need to verify the job on a wooden prototype.
The software post processes the program depending on the controller of the machine, to generate a CNC program This program can be directly sent to the CNC machine for machining of the core and cavity. The Reverse Engineering project thus ends with the creation of molds of the component.