Cases
Holden Engineering wins the race against time thanks to forward engineering
From damaged part to casting pattern in only 20 hours
We scan damaged components and design right away on the resulting data, eliminating the reverse engineering process and maintaining the original scan’s accuracy. The time and cost savings realized by working directly with scan data in 3-matic software are key for Holden Engineering to continue our success.
Holden Engineering have invested in the latest technologies, to become one of the first engineering companies to embrace forward engineering. As a manufacturer of replacement components to the historical motor sport industry, they have to work from the original, often damaged components. 3-matic software enables them to manipulate the scan data from these components directly instead of reverse engineering the data first. By using forward engineering Holden Engineering can reduce the process time for producing patterns by 60%.
Forward Engineering: the ideal formula for Holden Engineering
One of the first projects where Holden Engineering implemented forward engineering was the reproduction of the damaged rear upright for the March 711 F1 car (see insert on backside). They were faced with a very tight deadline: the car needed to be competing in Monte Carlo in two weeks.
The manufacturing of replacements for the historical motor sport industry starts with the original, often damaged components. Currently, companies use laser scanning to create a highly accurate 3D model or point probing to dimension components.
They then spend considerable reverse engineering time and effort to create a CAD model, to base the design and production of replacements parts on.
When making replacement castings for suspension uprights the typical process time for producing patterns takes on average 60 hours of highly skilled pattern making.
Next they use DEPOCAM software for quickly generating highly efficient tool paths over the triangle mesh designs made in 3-matic. The level of automations that can be created makes the NC code generation very productive.
This is a true forward engineering process. Everything was performed directly on the mesh data so the time and efforts previously spent in reverse engineering could be eliminated.
In a couple of hours, we can accurately capture the geometry by laser scanning. Next, using 3-matic software from Materialise, we can produce 2D drawings or pattern designs directly from the scan data. This means we miss the reverse engineering steps and we maintain the accuracy of the original scan. Our design times for an upright pattern are reduced to around eight hours.
About the March 711 F1 car In 1971 March Engineering came up with the Formula 1 711 chassis. While Robin Herd had designed the mechanical side of the 711, Frank Costin gave it its aerodynamic shape with an ovoid front wing described as the Spitfire. They finished second on four occasions, and Ronnie Peterson ended as runner-up in the World Championship. The 711 is powered by a Ford Cosworth DFV V8 3 litre engine, producing 500BHP.
What is forward engineering all about
Scanning technologies on the rise
It would appear that data capture by scanning technologies has come of age. The relatively recently improved accuracies (50 microns and higher) have led to a rise in the adoption of scanning by industry. The output of the scanner is usually point data or a STL file (Standard Triangle Language). In addition, CT scanning gains ground for technical applications since it captures also internal structures and thus allows for extensive nondestructive testing. Regardless of its origin scanned data tend to be large, complex files that need to be translated into 3D models in order to be able to manipulate it further.
Reverse Engineering: a lengthy, error-prone process to be able to design on scan data
Reverse engineering has always been assumed to be the next step in the process chain. The ultimate goal is then to force the scan data by some means into one of the wide variety of CAD packages on the market. Engineers have spent countless days fitting splines and polylines through the thousands of points of scanned data in an attempt to produce surfaces that can be imported by their CAD software. Often these efforts are made to get the scanned model ready for CAM, FEA/CFD analysis or rapid prototyping or manufacturing. Typically all these applications will triangulate the available surface data. In effect we are back to where we started but with deviations far in excess of the original scan data.
Forward Engineering: bring the design tools to the scan data directly
Why do we continue to follow this lengthy, complex process? The answer is that the applications to manipulate the STL file or point cloud are not readily available in the majority of CAD software’s. Materialise have devoted considerable resources to inventing an alternative, more rapid process chain. The concept of Forward Engineering is simple in its aim. Why bring the STL to the design package when you could bring the design tools to the STL file?
3-matic software has been developed to provide the design tools required to reconstruct and manipulate scan data. Its digital CAD kernel allows you to combine scanned and CAD geometries in a single project. All geometries are resolved to the simplest entity of all: the triangle. The kernel then enables you to do the rest, should it be the reconstruction of a 3D model for rapid prototyping or analysis purposes or even the design of machined components or tools and patterns. If you require the data for analysis, you can use the re-meshing algorithms to produce a low skewness boundary mesh for FEA or CFD. You can also reduce CAD preparation times for analysis by working with a triangular mesh at the very start.
For more information 3-matic@materialise.com
Holden Engineering
Chris Perkins
Tel 01332349475
info@holdenengineering.co.uk
www.holdenengineering.co.uk