Peter Zelinski has been a writer and editor for Modern Machine Shop for more than a decade. One of the aspects of this work that he enjoys the most is visiting machining facilities to learn about the manufacturing technology, systems and strategies they have adopted, and the successes they’ve realized as a result. Pete earned his degree in mechanical engineering from the University of Cincinnati, and he first learned about machining by running and programming machine tools in a metalworking laboratory within GE Aircraft Engines. Follow Pete on Twitter at Z_Axis_MMS.
Hyphen is a Toronto company making prototypes. It has extensive 3D printing capability, but as this video produced by Haas Automation shows, the company considers CNC machining to be an effective prototyping resource.
Another prototype house that frequently chooses CNC machining over 3D printing is Designcraft.
Hoosier Pattern made this likeness of a classic foundryman. The figurine was 3D printed in sand.
Through 3D printing, the Decatur, Indiana, maker of foundry patterns is reinventing the way it serves its customers. Typically in casting, sand is packed around the pattern and packed into a core box to create the components of the mold that will shape the metal. Today, Hoosier Pattern can skip the pattern and skip the core box by directly printing these sand components. Going straight to sand in this way is such a big change (and provides such big freedoms) that many of the pattern maker’s customers are only starting to grasp the potential. Read more here.
The 3D printed figurine is essentially a side effect. The ExOne machine performing the sand printing is large enough that a number of simultaneous jobs can be nested within its work volume. With unfused sand providing vertical separation, that nesting can even be three dimensional. All that is needed for this nesting of parts-over-parts is for spacers to be added to the collection of CAD models to ensure the vertical separation.
Initially, Hoosier Pattern’s team members added simple blocks to provide the spacing. But why be so plain? In 3D printing, a complex form is just as easy to generate as a simple one. Therefore, the company began using the geometry of this foundry industry symbol as a spacer instead. When the engineer needs to vertically separate two jobs, he pulls in this figurine’s geometry and positions it between the different CAD models. That means numerous figurines might be produced in the course of running any batch of parts. The result has been an abundance of the figures, which the company gives away at trade shows and other events.
The photo below gives a sense of this nesting inside the sand printing machine. The document in the foreground is a map of the nesting for the build of parts that has just been completed. Clearing away the unfused sand will reveal various customer cores and other casting mold components, as well as various spacers.
(PS: The photo of the figurine above is a close-up inside the display case in the office area where Modern Machine Shop’s editors work. We added this case to display interesting parts our readers have produced, and because we just got it, it’s nowhere near full yet. There is still plenty of room to add other cool parts supplied by our readers. Hint, hint.)
The cover story of the latest issue of Additive Manufacturing describes how a contract CNC machining business serving the medical industry is now leading some of its customers into additive manufacturing. Also in this issue: A review of what was on display at Euromold, one of the world’s leading events for showcasing industrial additive manufacturing technology. The digital edition of this issue is available now. To subscribe to Additive Manufacturing, go here.
If additive manufacturing is to account for a respectable share of production in the future, it can’t rely on primitive methods of finishing such as hand sanding. That point has long been apparent to 3D printing contractor RedEye, which recently completed its beta testing of various finishing methods for parts made through fused deposition modeling. Processes including tumbling, vapor smoothing, bead blasting and plating have now been added to its range of services. In place of surfaces with layer lines, these finishing methods can produce a smooth or shiny appearance appropriate to a visible consumer part. Read more here.
Dual-column machining centers being produced at Okuma’s production facility in Kani, Japan.
According to machine tool distributor Gosiger, a dual-column or bridge-type machining center is 10 times more thermally stable than a comparable “C” style machine. Because of the dual-column design, says the company, heat affects the bridge structure linearly. The machine expands only in a straight line, allowing dimensional changes to be compensated electronically.
The dual-column design also places the spindle nearer to the center of mass of the machine, increasing rigidity. Read more in Gosiger’s article about dual-column machines.