Posted on

Reverse Engineering a Propeller

This project was a great example of how modern technology can be used to reverse engineer obsolete components that are no longer readily available. In this instance Albatross Marine were running low on ‘new old stock’ of propellers that they supply for Albatross boats. They sent me one of their last stock propellers in order to have it reverse engineered and re-produced.

Scanning

First of all the propeller was 3D scanned. This was done to an accuracy of 0.25mm using a Shining 3D Einscan H, handheld 3D scanner. The 3D scanner is used to take millions of surface measurements to replicate the item and generate a 3D mesh.

AESUB 3D scanning spray was utilised in order to make the propeller easier to scan. This is a non-marking spray that turns shiny objects to a flat white finish, while only affecting their surface dimensions by a few microns. Within a few hours it evaporates with no need for cleaning and without leaving any trace on the part.

Reverse Engineering

The next stage of the process involved reverse engineering the propeller. In most instances this involves drawing a new component inside or over the top of the scan mesh. Some interpretation is often needed to overlook small errors in the scan data or defects in the original part that may not want to be replicated.

left – you can see the blade profile being replicated in Fusion 360. The mesh modelling environment has a ‘pull’ feature which allows you to stick the surface that you are modelling to the scan mesh. You can also see how the cast propeller surface is faired out.

Making Corrections

The part that you are scanning may sometimes be slightly different from what you actually need to make. In this instance just the hub and one of the blades were modelled, the one blade was then distributed around the central axis to give three perfectly balanced blades.

Finally the finished model was upscaled by a 1 in 65″ factor, as determined by the casting shop, in order to account for shrinkage during the casting process. This will ensure that the finished propeller is produced in the correct size. Tabs were also added to the hub to aid the casting process.

Re-production

The new propeller will be 3D printed, cast and machined to create new stock that will be available to buy through Albatross Marine.

Albatross Marine

Albatross Marine offer a full range of services for Albatross Boats – from a few rivets that need changing, to a complete rebuild. They also supply new old stock and re-production parts.

Follow the links below for more information or visit their website.


Contact Me

If you are looking to have a component 3D scanned and reverse engineered then please feel free to get in touch and we can discuss the best approach for your project.