When people image the production departments of the biggest markets in the world, they think
New vehicle models take shape from wood and clay. The designers create the car unique model features on a wood model covered by a special clay, this help them to create unique shapes and character line. Once the clay prototype is created, engineers need to convert it into a 3D model.
Clay models are fragile and cannot be measured withCMMs machine or any other contact measurement.
But, they can be acquired with not contact measurement such as 3D scan.
Even more when it comes to repair a classic car, this could be a problem not to underestimate. Original design may not exist anymore due to companies failure and restore company needs to stock a huge amount of out of production parts. vanderKampen solid modeling U.A. is the specialist
of scanning and reverse engineering in Netherlands. A Mercedes-Benz 170S damaged rear fender needed to be restored and they were tasked to carry out this work.
HOW TO DEAL WITH THE PROBLEM
Since the size object exceeds the 2.5 times working volume rule (2.5 x 450 mm = 1125mm) it’s recommend to use a phogrammetry system. Uncoded photogrammetry targets, that will be also used for alignment afterwards by Open Technologies system, are applied on the fender.
A set of coded marker were added to the prepared part along with the reference cross standing beside the object. This photogrammetry skeleton will be used by the scan software to bound all the range images to the fiducial targets. Once the scan is complete, the mesh will be imported into a reverse engineering software and finalized.
HARDWARE AND SOFTWARE SET-UP
Cronos Dual 450 mm 2.0 Mpx
Optical RevEng 2.4
1- Non coded markers and coded markers are applied on the object. Several shot with a photogrammetric camera are taken in order to acquire the object references.
2- It was decided to use a Cronos Dual 2.0 Mpx 400 mm volume of measurement. The scanner will acquire accurate 3D images and every object feature will be detected.
3- After you imported the xyz coordinates of the photogrammetry skeleton the scan procedure can start. The scan process takes about 20 minutes and once the object is complete, a mesh can be generated.
4- The mesh is enhanced with Open Technologies software Optical RevEng. These operation of hole filling, smoothing and mesh fixing will make the file suitable to be imported into a reverse engineering software without any other operation.
5- A polygonal mesh is an output file that can be imported in almost every 3D software. Optical RevEng allows you to obtain the maximum optimization of your mesh in terms of smoothness, feature and style lines enchantment and lightweight of the computational load.
6- The reverse engineering operation are carried out with DesignX, a 3D systems software. Formerly known as Rapidform XOR, is a reverse engineering oftware that combines history-based CAD with 3D scan data processing so you can create feature-based, editable solid models compatible with CAD softwares. Once imported in the software, the 3D data doesn’t need any post processing enhancement because it was already fixed previously in our software Optical RevEng.
Acquiring a 3D model of a classic car parts have many advantages that not only restrict to the reverse engineering of a broken part. 3D models don’t have an expiration date, you can store them in digital archive and use them for further modification. Cronos Dual allows you acquire the object with accuracy and the 3D file can be imported in any third-party software. The 3D model can be manufactured in many ways; CNC machining, CAD/CAM/rapid prototyping. It can be, also, directly ispected.
If the dimension of the part is bigger than 2.5 times the scanner field of view Photogrammetry data can be imported in Optical RevEng to assure a better Occuracy. The flexibility of Open Technologies systems allows you to decide how you prefer to face these task with the advantages of an optical measurement system.