The RAM team continues to do more printing and testing to help ensure the new technology’s widespread acceptance. One part, printed for Design Concepts/Marine Concepts (DCMC), is a direct mold that would be used to create lightweight carbon fiber mold insets for a 60-plus foot deck liner.
“The part, measuring 10 x 4 x 2 feet and weighing 1,000 pounds, was large enough that it pushed the envelope for them as far as size, and it also aligned with one of our internal R&D projects, which was to develop an alternative to heavyweight standard mold insets,” says Ross Kennedy, director of business development at DCMC.
Company representatives watched the part being printed on the RAM equipment and shipped it back to their facility to mill. “It was a learning experience for everybody,” says Kennedy. “We got to understand better ways to index these oversized, near-net shape prints and provided feedback.” DCMC also tested the vacuum stability and surface finish on the printed molds.
Milling the printed thermoset composite was similar to milling a very high-density urethane tooling board. “The benefit that I see with the 3D print is that you can have a sparse interior, which uses a lot less material than a giant block of tooling board,” says Kennedy. In addition to lower material use and weight, the near-net printing discipline directly translates to less material having to be milled away.
Research on RAM has been slowed by coronavirus-related shutdowns, but when work can resume the RAM team will print another part for DCMC to see if the changes that they’ve made to the machine and the process have improved the printed product.
In the long term, Kennedy says there are three criteria that RAM-printed parts will have to meet for the equipment to gain a place in large tooling shops. One is the surface quality – the density and hardness – of the printed part. It will also have to meet glass transition temperature requirements and offer the right coefficient of thermal expansion properties. He expects that thermoset 3D printers like RAM will be able to meet those criteria very soon.
“We certainly feel that at some point this will become an everyday item in the larger tooling shops around the world,” he adds.
The RAM team will resume its research once work schedules at ORNL permit. ORNL and MVP have recently signed a second creative research and development agreement (CRADA), and Polynt is waiting on approval of its second CRADA with ORNL.