Design CAD/CAM package helps clear path to innovation
To design and produce a space-efficient collapsible snow shovel, a plastics moulder turned to Vero Software’s VISI suite.
A collapsible snow shovel with a two-hinged handle has been designed and manufactured by the plastics-moulding specialist Senior & Dickson Ltd. of Doncaster, UK, with the help of the VISI suite of CAD/CAM software from Vero Software Ltd. The shovel is aimed primarily at motorists because of its handy folding design, but its interchangeable shovel and fork heads make it useful also to householders wishing to keep driveways clear of snow and other debris.
With experience in injection moulding, toolmaking and rapid prototyping, Senior & Dickson can readily develop ideas from concept through production. It employed the VISI CAD/CAM suite to design the head configurations, specialised handle and 3D tooling for the snow shovel, and to create the CNC tool paths for machining the steel moulds. Design work and electrode extraction was performed in the CAD office and tool paths were programmed in the shop next to the milling machines.
“We moved the CAM onto the shop floor as the machinists are closest to the action and can react immediately without having to wait for the design team,” explained Chris Hodgson, technical director of Senior & Dickson. “They know what tooling is available and how to best machine an insert or electrode.”
The VISI Modelling module was used to design the handle from scratch and then to strengthen it through the addition of more ribbing to the original model. The software made it easy to apply the changes to the tooling inserts. Based on the industry-standard Parasolid kernel, VISI gives users complete flexibility to construct, edit, deform and repair complex 3D data.
Trials beget changes
After trialling the first prototype, said Hodgson, the engineers chose to add cross ribbing to the shaft to increase lateral strength and to apply larger radii to remove a localised stress point causing part failure during testing. “This was very easy to do in VISI because the software is not constrained by rules or a previous design history,” Hodgson recounted. “You can simply jump back into the design process at any point; you’re never stuck with a model that you can’t alter.”
Once the model was finalised, the company used VISI Mould to design the 3D tooling. The mould for the shovel head is made from P20 pretreated steel and processes fatigue-resistant recycled polypropylene. The shovel handle and folding mechanism are produced from high-performance polycarbonate in a mould machined from H13 hardened steel.
Before switching to VISI from another high-end software system, Hodgson said, Senior & Dickson often needed two or three weeks to produce tooling for a project; however, Vero’s software has reduced that time to three or four days. Indeed, with VISI, the design office can be more productive with a smaller staff.
Hodgson believes that his company would not be as successful without VISI. “We do not specialise in any one particular area,” he concluded. “But thanks to VISI, we master them all.”
Vero Software Ltd.
Cheltenham, Glos, UK