Page 30 - 3D Metal Printing Winter 2018

3D A Different Kind of Company, From Start to Finish
This direct-metal-laser-sintering machine builds parts that route to an adjacent surface-finishing machine at Harbec. Simple installation and quiet operation make the finishing-machine’s location ideal, according to Harbec officials.
company’s founder, Daniel Hutchinson, at an AMUG con- ference.
“We found out that Daniel was from nearby Buffalo, and we were looking for finishing equipment, though not sure exactly what kind,” Schneider recalls. “We met a number of times and brought in one of PostProcess’ first surface-fin- ishing machines, almost a pro- totype model.”
Edge rounding was Harbec’s biggest concern with tumble finishing.
“Many equipment manufac- turers can deliver a surface fin- ish, but we would end up with washed-out part features and broken corners,” says Schnei- der. “A machine’s energy would be focused on corners as much as everywhere else.”
Equipment Delivers
programmed recipes, built from hundreds of benchmarked parts of almost every 3D- print material on the market. The Milli features a noise-suppression enclosure and single-button operation. It is self- contained, with premixed chemicals poured in, parts added, and the machine set to its programmed cleaning regimen with chemicals dispensed into the clean- ing media automatically. Then, finishing can be forgotten as operators return to printing or other duties.
In operation, the machine combines vertical motion with PostProcess’ report- edly environmentally friendly consum- ables to achieve the required surface fin- ish. The Milli, ideal for larger parts with its 28 by 10 by 12-in. work envelope, can employ a divider to run two smaller-enve- lope sizes with different abrasive media.
PostProcess, claiming to be the first and only provider of automated and intel- ligent post-processing for 3D-printed parts (see Smart Finishing Takes Shape subhead), estimates that using its tech- nology can provide cost savings of 90 per- cent as compared to full-manual-labor finishing, with an average ROI of 17 weeks.
Employing the automated surface-fin- ish technology required only a short learn- ing curve, according to Schneider.
“Canned programs within the machines enabled us to get started quick- ly,” he says. “We plugged in the machine, gave the operators recipes for the solution media based on the metal alloys to be fin- ished, and let the machine do the work. With set programs, it is simple to get up and running. And when we were com- fortable we could go in ourselves to opti- mize the finishing programs for our par- ticular materials and needs. Custom recipes then are saved for future use.”
“Differentiating PostProcess’ machines, other equipment not specifically designed for 3D printing and these types of parts would have rounded corners and washed-out part features,” Schneider says. “The surface-finishing technology we now have does a great job of creating homogeneous finishes without breaking down the corners.”
Now, while cycle times for finishing
manufacturing is that you can just print a finished part,” says Schneider. “A lot of companies using 3D-printing equipment don’t really look at finishing. The industry has to overcome that and get on board with the finishing end of things before we really progress.”
Schneider sees a part as halfway done after printing.
“We CNC-machine 85 percent of the parts that come off of our machines, just for accuracy,” he says. “Tolerances may be ±0.005 in. coming out of the machine, and our aerospace customers, for example, want less than ±0.001 in. So initially we look at the geometry and figure out exactly what areas must be machined to tight tol- erances. We add additional stock to those areas. And, if we have surface-finish requirements, then we plan on tumbling the parts to meet those requirements.
In tune with the importance of rapid, accurate finishing, in 2015 Harbec brought in a prototype finishing (tumbling) machine from PostProcess Technologies (www.postprocess.com), after meeting the
Advanced Post- Processing Capabilities
With what can be best described as smart technology, PostProcess’ machines employ algorithms that control energy distribution. The algorithms work in com- bination with the chemistry of cleaning agents, the material properties of the cleaning media, and hardware that enables the entire system to function effi- ciently and quietly.
In 2017, Harbec brought in a new Post- Process Milli machine, incorporating newer technology and designed to prac- tically eliminate noise. Harbec stations the machines directly next to its metal printers. During 3D Metal Printing’s visit, we saw it positioned adjacent to an EOS M 290 direct-metal laser-sintering system. Only a 120-V electrical hookup is required to power the Milli, and like all of Post- Process’ finishing equipment, the machine at Harbec rests on coasters for simple movement to wherever needed. The fin- ishing machine’s proprietary AutoMat3D software computes cycle times with deter- gent dosing based on the software’s pre-
28 | 3D METAL PRINTING • WINTER 2018
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