Keeping Kenworth moving

The size of the Australian continent, its geographically dispersed population base and the importance of major commodities to its economic output means that freight transport sector performance has a significant influence on national productivity and efficiency. Figures surrounding the industry are significant. Trucking handles more cargo than trains, ships or planes, carrying more than 2,100 million tons.

Moreover, according to the Australian Bureau of Statistics the trucking industry is worth over $40bn and employs 140,00 Australians. Trucks are an essential part of our economy. Without trucks, goods would never get from suppliers to manufacturers and into the hands of consumers. Just as the economy depends on the trucking industry, the trucking industry depends on high-quality equipment.

Kenworth Australia has built a reputation around superior-quality, custom-engineered trucks with proven reliability over 47 years of local manufacturing. It manufactures around 2,200 trucks every year for delivery, and has the largest amount of 2015 models on the market. So, when Kenworth was faced with a late design change that threatened the production timeline of its major selling truck lines, it couldn’t let tooling lead time get in the way.

The challenge

In May 2014, Kenworth had designed a new HVAC (Heating, Ventilation and Air Conditioning) system with Delphi Automotive Systems on its “T” series of trucks, but a late tooling change to the under-dash ducting system meant the HVAC units couldn’t be fitted. The under-dash duct component connects the HVAC outlet bezel to an air distribution manifold on the underside of the dash. The tooling modification was necessary to accommodate both the new HVAC unit and incorporate a new design to improve airflow, assembly and suit the method of manufacture.

The duct component was originally set to be rotationally moulded out of PC-ABS, but the tool modification would take six weeks to complete, putting production of 320 trucks on hold. Kenworth was planning to assemble seven trucks a day for seven weeks from May into June. Halting assembly for even a day would potentially cost the company $2m in revenue.

“Parking half-assembled trucks, making the duct a ‘dealer fit’ requirement or delaying production was out of the question,” said Delphi engineer Ben Dejong. “We needed a process that could build the parts while the was tool was being updated.”

With an approaching deadline, a production solution needed to be found – and fast.

The solution

Delphi had been working with Stratasys Direct Manufacturing’s global partner in Australia, Objective3D Direct Manufacturing, for over six years for various prototyping and injection moulding projects. Stratasys Direct Manufacturing’s Global Manufacturing Network consists of member facilities connected around the globe that have many of the same services and expertise as Stratasys Direct Manufacturing.

“We had already been working with both Kenworth, and with Ben and Delphi, on the prototypes to ensure assembly and fitment, ” said Matt Minio, Managing Director at Objective3D Direct Manufacturing. “Both companies had confidence in FDM technology, and it seemed like a logical progression to then scale up from prototype to a production solution. Our role then transformed from rapid prototyping shop into a just-in-time manufacturing supplier.”

Objective3D Direct Manufacturing’s project engineers recommended fused deposition modeling (FDM) 3D printing technology to manufacture the ductwork for several reasons:

• Material – Delphi wouldn’t have to change the material of the designed component. They could build it in the same engineering-grade thermoplastic (PC-ABS). Changing materials would have demanded additional design modifications and set back production again.
• Speed – Objective3D Direct Manufacturing optimised the build orientation and packing to nest three parts across three Fortus FDM systems to manufacture nine parts a day, meeting production needs and reducing build time from 15 hours to nine hours.
• No finishing – The ducts are considered ‘under hood’ components and purely functional (not visible), so therefore they didn’t require sanding, smoothing or any coatings. All the finishing team had to do is dip the parts.

“Speed was our main objective with this project,” added Hugh Tevelein, Objective3D Operations Manager. “We had to optimise everything we could to help Kenworth keep production moving. We worked to a 24-hour schedule with parts building overnight and then fitted to vehicles same day.”

The results

“Thanks to the capabilities and expertise of the Objective3D Direct Manufacturing facility and staff, we were able to produce end-use parts that allowed production to proceed unhindered, saving us from crippling delays,” says Dejong.

Objective3D Direct Manufacturing built 320 units over a seven-week period for Delphi until hard tooling was finished and ready to be incorporated into the production line. Putting production on hold for hard tooling modifications would have cost Kenworth millions of dollars and many unhappy customers. This just-in-time manufacturing solution allowed Kenworth to bring 320 vehicles to market on time and put into operation trucks that are vital to the economy. When there are bumps in the manufacturing road, engineers can count on 3D printing to maintain momentum and keep assemblies moving.

www.paccar.com.au
www.direct3dprinting.com.au
www.objective3d.com.au