A Reverse Engineering Case Study by Katsuya Tanabiki

The shield notch of a motorcycle helmet is broken and the spare part for fixing it doesn´t seem to be readily available. The perfect occasion to use modern technology to produce the spare part fast and cost-efficiently.

The notch is a small plastic part, so it’s a great part to replicate with the help of a 3D printer.

In the case of the helmet, two notches are needed. One to fix the shield at each side. Since only one notch is broken, the remaining notch is the key to designing and manufacturing a replica exactly fitting bespoke helmet.

An efficient option to successfully and precisely scanning objects of such a small size with the EinScan Pro 2X  is the use of the Fixed Mode in conjunction with the tripod from the Industrial Pack add-on.

The data results from the Fixed Scan came out as precise as expected. This data can now be used for Reverse Engineering in Fusion 360.

The first step is to import the scan data into Fusion 360 using mesh insertion.

First, a mesh cross-section sketch is created. The position of the cross-section is adjusted to an appropriate level and confirmed by clicking “OK”.

1. Right-click on the cross-sectional sketch and select Edit Sketch, as shown in the image.

2. Select Fit Surface to Mesh Section in Create Sketch.

3. Select Closed Spline as the type of curve to be fitted, select the cross section, and OK.

4. Although it not shown in the image, the step part is sketched in the same way. With this sketch curve that can be used for modeling, the sketch can be completed.

5. In the Solid tab, select Extrude, select the surface to be extruded, and specify the amount of extrusion to make it a solid body

6. Cut out the step part in the same way, using extrusion to create the step.

7. In the last step, the part needs to be filleted and chamfered to give it the same shape as the original part.

8. The solid body is now complete. By right-clicking on the body in the tab, the STL file can be created.

The Data is now ready to be 3d printed.

The part is so small that the printing process doesn´t take very long.

The one on the left is the 3D printed part.
Including the 3D printing time, fixing the helmet took about an hour.

Katsuya is all about bikes and cars. On his blog custom-auto-maruta.com he is sharing his projects using Fusion 360 and 3D printing in conjunction with his EinScan Pro 2X. He loves the power of 3D technology which enables him to make anything: original parts and 3D printed spare parts. The original article appeared in Japanese on https://custom-auto-maruta.com/goods/simpson-parts-reverseengineering/