Producing Geometry You Can Trust
QC provided an engineer for our project who did a great job of collecting the dimensional data for the parts to be reverse engineered, creating the CAD models, and producing prints for manufacturing. He kept in regular contact with me throughout the project, allowing us to quickly resolve issues as they arose. He was also very responsive when asked to make changes to the prints. Overall, a superior job.
- Paul,
Power Generation
CAD STL vs. Scanned STL - What is the Difference?
Some STL files work well in a CAD environment, while others cannot be imported. The difference between the files is often a result of how the file was created.
An STL (Standard Tessellation Language) file is native to stereolythography software for rapid prototyping. It is a facet-based representation that approximates surface and solid entities only with triangles.
When a CAD model is exported as an STL, very large triangles are created that represent planar features, resulting in a file with perhaps a total of 5,000 triangles. An STL created from a laser or white-light scan is a derivative of the point cloud. The point cloud does not contain geometric feaure definition such as planes, but includes all surface shape, defects, and texture. Therefore the STL defines curvature in many, many smaller, triangular surfaces. The resultant file is very heavy, often including well over 1,000,000 triangles. Most CAD platforms do not manage that type of file well.
For 3D printing, an STL from the scan is an ideal file type. But for useful CAD information, the point cloud should be surfaced and developed as an IGES or native parametric solid.
