Shopping trolleys get to the show in time

For many manufacturers, being able to verify new designs quickly and confidently in the form of a fully functional working prototype model, can help to increase confidence, cut lead times, reduce downstream manufacturing costs and lead to better overall products that exceed customers' requirements. For Supercart, a leading supplier of supermarket trolleys, its design team was recently faced with such a problem. The company's primary concern with any new trolley design is how the model will work in practice: will it look and feel right for users and will it stack properly with other trolleys? Apparently, 'stackability' is a vital factor for potential buyers of Supercart's products, given the limited space that supermarkets have available to them, especially when trolleys are not being used by shoppers. In late September 2004, Supercart's design team approached rapid product development specialist ARRK Product Development Group to help it develop a fully functional prototype model that would help the company assess its new design of trolley. Following a visit to ARRK's site in Gloucester, project leader at ARRK Craig Vickers was able to guide the design team through the various processes available. These included stereolithography (SLA), selective laser sintering (SLS), fused deposition modelling (FDM) and downstream services, including polyurethane castings, paint and texturing services. ARRK advised Supercart to have full-sized SLS prototype models produced. The trolley was produced in a series of sections using glass-filled nylon powder. This process offered Supercart excellent strength, durability and rigidity. Initially, ARRK's Martin Burgess and his team produced three separate prototype SLS models over a two- to three-week period. This process included numerous design 'tweaks'. ARRK has three SLS machines at the Gloucester site and so was able to offer Supercart significantly reduced lead times. Following assembly and trial stages, several modifications were made and incorporated successfully into the design by grafting them into the existing units. By doing this from the beginning, valuable time was saved and additional unnecessary expense saved in having to rebuild the complete trolley from scratch each time. The project was completed on time and within budget, but also enabled Supercart to exhibit its new trolley on its stand at the global retail trade show 'EuroShop', held in Düsseldorf, Germany in February last year. To attract potential buyers to Supercart's stand, ARRK delivered one trolley direct to Supercart's stand at the show. The trolley was fully finished and painted red and silver. Due to the positive attention this trolley received at the show, another trolley was later fully finished and shipped to Supercart's other facility. According to Marc Bouvier, marketing manager at ARRK, Supercart has subsequently requested further prototypes for several other trolley models for future launch.