Additive-produced parts are porous, rough and expensive? Rob van Loon and Ruud Hurkens of KMWE Precision can dispel these misconceptions about 3D metal printing based on their years of experience at Brainport Industries Campus. They did so during the Precision Fair, where they showed in their presentation how metal additive manufacturing saves 200 hours of cleanroom assembly on one part.
Eight years, that’s how long KMWE Precision has been active with additive manufacturing of metal parts. Rob van Loon, AM engineer, and Ruud Hurkens, engineering manager, outlined the trajectory the supplier of precision components has already taken during the Precision Fair. Including the validation process, together with K3D/AddFab, also located on Brainport Industries Campus. “We are working on volume production with 3D printing,” says Ruud Hurkens.
Call 99.9 percent non-porous
Critics often point to the high cost of metal additive manufacturing. Also, the porosity would be too high and the parts have too rough a surface. The two AM experts from KMWE Precision managed to disprove these assumptions one by one in their presentation. The density of the parts that KMWE obtains on the MetalFab1 at K3D/Addfab is always 99.9 percent. “Don’t call this porous,” says Rob van Loon. And five years ago the roughness of the parts was indeed not good, but now the supplier easily achieves a Ra value of 3 µm and also Ra 2.4 µm. “We have already reached that level with our process knowledge,” Ruud Hurkens adds. And with post-processing, including electrochemical machining, much lower Ra values are achieved.
Shifting costs and risks, which saves lead time
Both were also clear about the costs at the Precision Fair: you should not look at the costs of the component, but at those of the entire composition. To underline this, they cited a case from the aerospace industry. KMWE Precision manages to engineer a component for an optical measuring instrument in such a way that it can be printed in one piece. One goes from 100 parts to 1. That saves 25% weight. It is now possible to achieve the tolerance of the composition, because all tolerances are integrated in the design. And 200 hours of cleanroom assembly are saved. “Just like the risk, the costs shift,” explains Rob van Loon. “The risk is shifting from assembly to production. That saves lead time.” And the total costs are the same. So is AM expensive? “New. The costs are different.”