The combination of clay modelling, point cloud processing, 3D modelling and rapid prototyping has enabled the fast development of a controller handle for snow ploughs

Reliability is an overriding requirement in FORCE America’s designs, but its controllers also have to be ergonomically flexible to accommodate interaction with different-sized hands.

The resulting controller handle is designed to accommodate three different joysticks for controlling plough blades, three switches for salt distribution, and the electronics to control and light the device.

The controller handle project epitomises ADC’s expertise in the point cloud data processing technology that enables users to move efficiently between the physical and digital worlds. At the centre of the process is Geomagic Studio software, which ADC has used for a wide range of projects, from custom fuel tanks for Harley-Davidson to airships, or blimps.

“Geomagic Studio fundamentally changes the way you can design,” says Mark Schaefer, ADC president. “It provides the tools that enable you to make a quick leap from a physical model with a shape and feel everyone likes to an accurate CAD model for manufacturing.”

Project development

At the start of the project, FORCE America gave ADC the internal components that would be required in the new design and a rough clay model of the shape. Using Pro/ENGINEER, Schaefer created CAD models of the buttons and circuit board areas based on existing drawings and 3D scans. He then created a volume model around the components to provide a clearance guideline for the clay work.

ADC used the Objet system to produce a rapid prototype (RPT) of a volumetric clearance model for the controller’s internal components. This allowed Chris Mulhall, a senior engineer at ADC, to add clay to the RPT model and guarantee that the final offset (the wall thickness of the part) would not interfere with any of the pre-designed internal components. Mulhall then added clay to create the intended shape of the controller. Changes were made to the clay by hand until the look and feel was right. Using clay as the medium to get the shape right saved about a month in CAD and physical prototyping iterations, states the company.

Greg Groth, reverse engineering manager at ADC, captured the geometry from the clay model using a GOM ATOS white-light scanner, then saved the data as an STL file and imported it into Geomagic Studio software. In the software, he smoothed out inconsistencies in the clay surface, made the button area flat, and created models for the top and bottom shells of the controller handle and a safety switch for the back of the controller. The models were turned back over to Schaefer, who generated parting line surfaces and curves in Pro/ENGINEER.

These models were then brought back into Geomagic Studio, where Groth modified the parts to meet tooling draft requirements. Once the drafts were set, Groth created offset surfaces to maintain the wall thicknesses of the parts, then used Geomagic Studio to create surfaces of the final parts and define the offset internal geometry.

From Geomagic Studio the surfaces were brought back into Pro/ENGINEER, where structural ribs, holes and assembly features were added. The final models of the handle – top, bottom and safety switch – were printed on the Objet system, and the parts were assembled for final approval.

“Once the clay model was perfected, it was only a matter of days to move from scan data to a final, tool-ready prototype with switches and components ready for installation,” says Schaefer.

Generating high quality product designs

Groth commented: “The combination of Geomagic Studio and Pro/ENGINEER enabled us to quickly capture the clay model, check the draft, and modify the surface geometry to make the controller manufacturable,” says Groth. “This is a perfect example of Geomagic reverse engineering and CAD working together to generate a high-quality design very quickly.”

The job, scheduled for six weeks, was completed in just three. While ADC was completing the handle design, engineers at FORCE America were able to work on other parts of the new system assembly. Most importantly, ADC was able to ensure design quality in the early development stages.