Case Study 1 - Checking moulded components

At the Bosch Lawn & Garden lawnmower plant in Suffolk recently, during new tooling trials for their award winning Rotak lawnmowers, dimensional variations were noted in complex injection moulded components.  This resulted in mis-matching of components during pre-production assembly trials.

Bosch approached En-scan through Minima Design to advise because these variations could not easily be identified by measurement or by normal inspection methods. Bosch had to work within tight time-scales as toolmakers were waiting to introduce tooling changes based on the results of their investigations.

Bosch had to quickly identify the differences between complex injection mouldings from different tools and from different cavities of the same tool and their conformance to the original CAD data. Secondly, Bosch had to investigate the implications of each of the variations on the assemblies of components.

The ExaScan used by En-scan is the world's only high accuracy handheld scanning solution that does not require a secondary positioning device, such as a CMM or a portable arm. Consequently, En-scan is able to offer a truly portable, fast and cost effective scanning service which Bosch had previously been unable to access.

• Truly portable - meaning that we can come to site and get into some tight corners
• Fast - data acquisition is fast and effective due to real-time on-screen surface display
• Cost effective -STL file output - no more point clouds to manipulate
• Self positioning - makes it highly flexible and able to cope with assemblies of  parts
• Accurate - standard accuracy +/-0.1mm - high accuracy +/-0.05mm thanks to a third camera

En-scan was on-site to assess the extent of the job at Bosch within five hours of the original phone call.

By 9 a.m. the following day, Bosch agreed the scope of work outlined in the initial meeting and final mouldings were received at 10 am on the next working day.

By 9 a.m. the following day, En-scan delivered 50 STL scan files to Bosch.

Relying on En-scan's generation of meaningful origins within the scan data, Bosch imported the STL files into Pro-Engineer, laying them over each other and over the original CAD data of the parts which allowed the Bosch designers to quickly compare the actual scanned geometry of the parts to the original master CAD data.  After a day’s investigation in the CAD environment, the Bosch designers had a detailed set of data indicating the areas of difference and concern with the components. This information was used by the tool-makers in deciding which areas of the tools or process needed attention.

Thus, within three working days, Bosch had answers to their questions, solutions to their problems and confidence in the accuracy of the results having removed the possibility of human error in the measurements.

www.boschgarden.co.uk