Fabricators and manufacturing firms suffer from tangible and intangible losses, resulting in heavy costs due to abrupt production downtimes. In such situation, when time and accuracy are at the zenith of product delivery, product manufacturers cannot afford slowdowns. One of the best means to avoid losses is to rectify designs and make them error free right from inception. Proper inspection followed by amendments at early design development stages or analysis stage will eliminate the downtimes and enhance production output.
This approach is very much critical for components and ancillaries such as valve or pump housing, engine casing, metal frames etc. that have outlived their drawings. With no prior availability of the design information, replacing these parts calls for reverse engineering or simply reengineering. The process that starts with laser scanning the existing part, followed by developing comprehensive 3D CAD model for manufacturing requirements. For accurate geometry of the final product, manufacturers demand to have accuracy in the CAD models tested for deviation from the original dimensions.
Deviation analysis avoids costly mistakes for manufacturers
To deliver accurate final products on time, it becomes necessary to eliminate design errors by comparing the generated 3D CAD model to some known standard or entity. By generating 3D CAD models through reverse engineering process, for accurate comparison and calculating dimensional differences of final CAD models, scanned data that is available as input is used as the standard value. The accurate comparison, commonly referred to as Deviation Analysis, involves rapid design verification of 3D CAD model, part-to-part comparison with the scanned data and tooling validation. Thus, it is of prime importance to have precise scanning of the component for accurate design generation.
Removing design errors early during the design stages enables to avoid manufacturing down times by carrying out smooth shop floor production. Moreover, fabrication drawings generated from error free models eliminates the rework in manufacturing processes arising from design defects. This empowers the manufacturer to reduce the waste of materials, time and cost; and hence increase the efficiency of the manufacturing facility with ensured safety of component.
Deviation analysis through point cloud scans VS Coordinate Measuring Machine (CMM)
Safety performance in regular operation of components is a responsibility of manufacturer and design engineer. The designs are prepared with accurate standards for fabricator to deliver the exact intended product. Though the manufactured part can always be tested for dimensioning and surface study through traditional methods like with Coordinate Measuring Machine (CMM), it cannot serve speedy results. While on the other hand, through deviation analysis the 3D CAD model is compared against the point cloud scan data obtained by laser scanning, which delivers faster outputs. Overlaying of CAD model over the scanned data gives accurate information and quick dimensional and geometric deviation analysis of the component.
Deviation Analysis allows you to find differences on two different meshes on upper polygon level. Tolerances, angles, curvatures etc. can be verified at one go. Each and every surface of the part is inspected for deviation through this technique, and it servers the purpose of eliminating the production downtime right in design generation stage; way before the production commences.
The image above is a 3D CAD model of a housing, which is compared against its point cloud scan for minimum deviation from the original design with deviation falling within allowable ranges. The 3D scanned data of the topography of component was not sufficient to generate information related to fabrication. Through meshing and other software modeling and sketching tools, 3D CAD was generated and compared by overlaying of scan cloud.
The manufacturer was thus able to save time, digitize the information and was catered with fabrication ready drawings for the housing. Data once scanned can thus help in inspecting various attributes of the component. In addition to this, the color map communicates how parts function in the assembly and deviation of individual part dimension. The deviation analysis shown here was performed using Geomagic Design X, a leading tool for reverse engineering projects.
When traditional inspection methods don’t always portray the entire picture of modeled industrial component; deviation analysis offers rapid, clear and more effective insights into component’s final performance. Through CAD software database offerings, design errors can be removed avoiding production downtimes by anticipating the challenges in design to reduce waste of time, money and other resources.