Figure 1
Design review
The project started with the receipt from the customer of a drawing (see figure 1), 3-D CAD model, and a specification for end-use.
A review of the drawing and the CAD models indicated that, although the overall concept of the design was satisfactory, a number of features could not be rotationally moulded and would need to be changed (see figures 2, 3 & 4).
Figure 2
One of the requirements of the end-use specification was unclear and their calculation based on these figures gave a total load which was extremely high and would undoubtedly have lead to failure of the product. tecni-form therefore clarified the figure with the customer and their new calculation gave a lower load. Unfortunately this still gave a marginal condition so tecni-form carried out a finite element analysis (FEA) yielding a factor of safety (FOS) of 0.5, proving that their initial concerns were correct.
Figure 3
It was agreed that the design needed to be optimised to improve its load-bearing as well as modified to remove the unmouldable features. This could not be undertaken by the customer due to limitations of their CAD system and it was therefore agreed that tecni-form would carry out the work.
Figure 4
tecni-form uses two systems in-house, Catia V5 and SolidWorks 2006; as the mouldings did not contain complex surfaces and due to system and staff availability tecni-form decided to use SolidWorks. The customers 3-D CAD data (a SAT file from AutoCAD) was therefore imported into SolidWorks and, although some geometry was used, a number of features were recreated to allow parametric history-based changes to be applied in response to the results of further FEA. This subsequently proved to be the correct course of action.
A look around the tecni-form website The tecni-form website is designed to be a comprehensive resource for Industrial designers.
