PROTOTYPING


component at a later stage incurs project delays and budget overruns Why, then, has the manufacture of prototypes been


so neglected? Traditionally, prototypes have been prioritised and progressed according to timeframe. Product development & project managers tend to focus on ensuring that all the required components are available by a certain date. In the worst cases, only once the components have arrived do engineers start worrying about how, and indeed whether, these components will fit together. The number of tolerance and assembly issues


identified at this stage is higher than many would admit. Fixturing can also cause problems, because investment in adequate work-holding equipment when adding remaining components is often the first to go in the drive to reduce project costs.


The best part you’ll ever make


Alan Francis of Productiv discusses a new approach to prototyping and argues that prototypes are the best products you should ever make


T


he subject of detailed testing and performance validation, a prototype part reveals whether any further design modification is needed, as well as providing vital data on the part’s published


performance attributes, warranties and service intervals. For these reasons, it needs to be the best part you ever make. Unfortunately, production prototypes are often


expensive and approaches to their development have not always kept pace with other areas of design, engineering and manufacture.


THE PROBLEM WITH PROTOTYPING Prototyping has not always received the attention it deserves. This could be for a variety of reasons. For one, production prototypes are often expensive, particularly when you compare them to the cost-per-unit of the component in its final form. There has also, arguably, been an inconsistent approach to prototype development, which has meant that it has not kept pace with its design, engineering and manufacturing counterparts. Unlike the mass-production of finished parts –


which involves detailed operations sheets, photos, precise written instructions and guidance on correct handling and fixing – prototype assembly is often created from a CAD representation at best. As a result, quality and repeatability can suffer. With most projects working to strict deadlines, re-engineering a


16 /// Testing & Test Houses /// March 2019


❱❱ Production Oriented Prototyping enrols the full involvement of design, test and production engineering


SOLVING THE PROTOTYPE PROBLEM Production Oriented Prototyping (POP) is a novel approach to prototype development that involves both the individual component and full assembly designs from the start of the application development phase. The aim is to build production standards into the prototype, while minimising cost and delivery time, as well as optimising safety. Using virtual builds, simulation and validation via


CAD, manufacturers can ensure that all the components fit together for each design release and can be accessed and manipulated during the build. Any issues with component compatibility, design or accessibility can be tackled at a much earlier stage and, crucially, before time and money have been invested in one-off component manufacture for the prototype. Using this method, the team can develop operation


sheets as they go, making the final assembly process easier and more intuitive. Fixturing and work- holding are also considered at an earlier stage, meaning manufacturers have more time to specify and produce a bespoke system, if required. In effect, assembly process design – including


process, flow, tooling and fixturing – is completed before the physical components are ready to be assembled.


HOLISTIC APPROACH By adopting this holistic approach, it’s easier to identify and fix issues faster than would be achieved during final assembly, with programme time savings of more than 25 per cent often achievable. What is more, the extra efficiency afforded by POP enables assembly technicians to identify cost reduction opportunities for components and processes through “practice runs” for future assembly. Tests of this method at Productiv have shown an


ability to reduce the assembly time for the first prototype build of a complex transmission for an automotive manufacturer from their typical eight weeks, to just eight days. The benefits of the POP approach can be


applied in any sector for which precision and reproducibility are vital to enable accurate testing and validation. T&TH


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52