Remembrance of something past

In the opening chapter of French author Marcel Proust’s seven-volume masterpiece “Remembrance of Things Past,” the narrator eats a morsel of cake dipped in tea. Its taste releases a flood of memories from 30 years before. Proust follows up the narrator’s remembrance with 2,200 pages that explore the effects of time’s passage on human relationships.

I had a more humdrum eat-the-cake moment recently while reading a white paper published by 3D Systems. The paper explains how the company’s tool-less digital molding process was made possible by a technology patented 30 years ago by the company’s co-founder, Chuck Hull, inventor of the stereolithography (SLA) apparatus.

I flashed back to a shop visit I made in the late 1980s to see a then-new technology in action: the SLA-1, the first commercialized additive manufacturing system. (Note: I won’t need 2,200 pages to tell my story; 220 words oughta do it.)

The suburban Chicago shop machined molds and prototypes. Its owner took great—and justifiable—pride in operating the latest 3-axis CNC mills, manufacturing software, and finishing and metrology equipment. After a quick shop tour, the owner said, “Let’s go see the thing.”

He led me to a corner of the shop and pulled back a black curtain covering the entrance to a small, dark room. In the center was the “thing,” an SLA that consisted of a computer, build chamber, laser, and tank filled with amber liquid.

Shop personnel hovered over the SLA like our early ancestors huddled around fire. I was transfixed, watching for nearly an hour as the part being 3D-printed took form in the photopolymer resin.

While driving back to my office, I was thoroughly convinced I had witnessed the future of manufacturing—and seen the immediate beginning of the end for milling, turning, drilling, and all the other subtractive processes I was familiar with.

I was wrong. The “end” didn’t come immediately nor has it come yet.

But sales of AM systems have increased steadily the past three decades. They quickly became the go-to equipment for rapid-prototyping shops, and in the past six to eight years have found a home in all kinds of manufacturing companies.

Wohlers Associates, which produces an annual report on the state of the additive manufacturing industry, estimates the global AM market was $5.17 billion in 2015, $6.06 billion in ’16, and $7.30 billion in ’17.

3D Systems’ co-founder, Chuck Hull, introduced the SLA-1 stereolithography apparatus in 1987. Credit: 3D Systems.

Moreover, Wohlers and other experts project AM will experience anywhere from steady to robust growth in the coming years.

Does that mean AM eventually will supplant subtractive and other conventional processes as the predominate way parts are produced? No. And certainly not in my lifetime.