A custom gun grip manufacturer has substantially improved the quality of its products by using the MobileScan HD portable 3D laser scanning system from NVision (nvision3d.com) to reverse engineer the original grips. In the past, the manufacturer used a coordinate measuring machine (CMM) to define the geometry of the mounting surface of the grips. But the CMM’s inherent accuracy limitations made it difficult to provide the desired fit and finish. The laser scanner, on the other hand, captures millions of points, making it possible to define the mounting surface to a much higher level of accuracy.
Custom gun grips make it possible for individuals to select the configuration that provides the best handling, pointing and recoil qualities. Custom grips also add a finishing touch that improves the appearance of a gun. Most custom grips are made from woods. Personalized touches, such as monograms or initials, can also be added to the grips.
One of the most important requirements in designing custom grips is defining the geometry of the back side of the grip. It would have been a very difficult and error-prone task to create this geometry by taking manual measurements of either the gun frame or the original grips. For these reasons, the gun grip manufacturer used a CMM to capture points one at a time from the original grip. But with a CMM it was only possible to capture a rough outline of the geometry. A considerable amount of work was required to fine-tune the design and accuracy was well below what was desired.
The grip manufacturer decided to investigate laser scanning and looked at several different scanners. The company selected the MobileScan HD 3D laser scanning system, which provides very high resolution with a point spacing of 0.001” and an accuracy of +/- 0.0005” while collecting measurements at a rate of 30,000 points per second. “The High Definition version of the MobileScan 3D provides a higher accuracy inspection and reverse engineering system than was available in the past,” said Steve Kersen, President of NVision. “Customers no longer need to choose between the speed of a scanner and the accuracy of a CMM.”
The scanner generates a point cloud consisting of the coordinates of individual points. The gun grip manufacturer uses software that comes with the scanner to convert the point cloud to a polygon mesh. Then they use reverse engineering software to convert the polygon data to a surface model. They export the surface model in the IGES or STEP format and import it into their CAD software. The model is then fine-tuned and toolpaths are created for machining.
“This gun grip manufacturer has been able to achieve a competitive advantage by producing grips that fit better and look better,” Kersen concluded. “Many other companies involved in the gun business have also discovered the advantages of laser scanning. For example, Soft Air USA®, Inc has reduced by 4 to 6 weeks the time required to get its licensed replica airsoft guns to market by using NVision’s Engineering Service Division to reverse engineer the real guns.”