January 8, 2018 - A fused filament 3D printer has saved a custom outdoor lighting manufacturer tens of thousands of dollars a year, improving operations and winning more business. The purchase also helped retain customers who would previously have gone elsewhere for specialized parts.
At an average cost of $3000 per part, the printer paid for itself after 10 parts, thanks to the 200 Series Workbench Classic from 3D Platform (Roscoe, IL). With 40 projects in 18 months, U.S. Architectural Lighting (Palmdale, CA) saved $90,000 to its bottom line after bringing master mold printing for sand casting in-house.
“With our old process of product development, we used to spend on average $50,000 a year with an outside service bureau printing mostly SLA parts,” said Tim Carraher, lead engineer. “The average part was over $3000 and we would have to wait two to three weeks or more to get it into our hands.”
The large-scale, industrial-class printer ensured customers who would have gone elsewhere to get their parts made faster now stay with U.S. Architectural.
Workers fiddled with the new 3D Platform machine for a couple of months before producing the first usable master mold. At first, they used familiar tools for post-production to smooth out the ridges that characterize 3D-printed plastic parts.
Mark Huebner, market development manager for 3D Platform, said: “They’re metalworking guys, so for them the plastic is not something they want to do. They were using hand-held grinders and putting holes in the plastic at first.”
Realizing their familiar grinders were too tough for the job, the metalworkers used an auto body filler with light hand sanding for post-processing on the plastic master mold.
After customer approval, they perfected the final finish on a metal mold for their production core box. The company’s low-volume, high-mix runs are ideal for this.
“I know other folks that’ll use a high-build primer like you find at a body shop. They will spray it four, five, six layers and then do a light wet sand on that, so they get a glass-smooth finish,” Huebner said.
Aside from post-processing, Huebner also advises on fused filament printing. “Vertical finishes provide the best surface finish,” he said. “Change curves or shallow angles to 45° whenever possible, which minimizes the need for supports that leave a scar when removed. This helps reduce the need for post-processing.”
Huebner continued: “When you do shallow angles, or you have a radius on something, think of the layers as beads of plastic that are being put on top of one another. So, they have to overlap as you go around a radius. The steps are much more pronounced when you do a curve. When you do an angle, they overlap consistently and you don’t have that same effect.”
He also recommends a paint brush-applied product from Smooth-On (Macungie, PA).
3D Platform has a partnership with Polymaker (New York) to make PolyCast filament that can be post-processed in a Polysher chamber, which sprays isopropyl alcohol on a part to smooth its surface.
“I’ve seen that used in smaller castings. It’s not a big chamber so you’re somewhat limited in size,” Huebner said.
For printing, Huebner mentioned graphene-enhanced PLA from Haydale (Greer, SC) which, he said, prints extremely well and burns out completely, as well as wax filaments from MachineableWax.com (Traverse City, MI).
“The printable wax, we’ve done minimal testing on it and it is a very tough material to print. But if it can reach a point where it’s more consistent in its output, that’s a material that [will be] very interesting to the investment cast industry,” he added.