Rubber Seal scan

3D scan

Could it be possible to find a cross section of a rubber seal without cutting it to find the profile?

A dilema that we overcame with the aid of 3D scanning, and 3D CAD software.

The seal in question is the seal shown here, approx half a meter in diameter, and 25mm in cross section. The customer wants to reproduce the seal in high quantities but only has one left in stock so cutting it the old fasioned way to find the profile is not an option:

Structured light 3D scanner

So the first task was to 3D scan the seal, the scanner used is the Einscan 2X plus, which is a structured light 3D scanner where the light source projects a series of patterns onto the object, usually in the form of multiple parallel beams, then the patterns become distorted when projected onto the object’s surface. The scanner captures these images using the cameras which relay the images back to the 3D scanning software. It uses these images and the software’s algorithms, using the method of triangulation, to calculate the object’s depth and surface information.

Scanning Challenges

So, A traditional scanner would find the continuous/symmetric shape and glossy black colour very tricky to pick up the 3D feature. But with the Einscan 2X plus there’s always a way.

1. First trick was to place the seal where it would be stable enough to stay in the same position while the scanner is rotated around to capture a 360°

2. Second trick was to place random features/3D parts to the seal to give the scan alternative features to pick up then the seal would be the secondary part captured in the scan:

Fixed scan

The Einscan 2X plus was then set to fixed scan, a total of 10 scans were taken so the scanner was rotated every 36° around the seal, this then captured a full 360° of the seal and other objects:

File conversion and completion

All objects and the seal were captured, but only the one section of the seal was required, so all the data that was not required could then be deleted (in red below), the grey part is the Seal that was kept to find the cross sectional profile:

Then finally the data from the Einscan software was meshed and enclosed watertight to produce:

The final output from the 3D scanner is a digital 3D representation on the computer in the form of an STL surface file so, not quite the end of the process yet, the next process is extracting a geometric shape which is fully dimensioned from this file. The Einscan 2X RED option comes with a version of Geomagis essential which is essential to create this type of file.

One click in the Einscan software and the Geomagic file is opened, this is now where the file can have all the surfaces extracted and a solid STEP or IGES file exported to any 3D CAD software. At Cammpro we use Autodesk Inventor 2020, so the file was cut perpendicular to the profile, so the geometric shape and dimensions could be extracted to have the profile within 0.05mm:

From this profile the customer can now mass produce the seal and save the original seal from being cut.

Contact Cammpro with any of your design, 3D scan or 3D print enquiries, no job to big or too small.