Stephanie (Monsanty) Hendrixson served as a Modern Machine Shop summer intern in 2012 and joined the team as an assistant editor later that fall. She currently works on event news for MMS Online and on the production of the print magazine. She also blogs about additive technology and helps to manage Additive Manufacturing magazine as its associate editor. Stephanie holds an M.A. in professional writing from the University of Cincinnati and a B.A. in English literature and history from the University of Mount Union.
The top image shows a portion of the control panel from the user’s side, where the micro-holes are invisible to the human eye. The bottom is a cross-section showing the micro-hole pattern.
How do you drill a hole smaller than the diameter of a human hair? Baltimore, Maryland-based Potomac Laser turns to UV laser micromachining for such applications. This process directs a laser beam onto the surface of a material and the energy of the laser is converted to heat which vaporizes or melts the material. With this technology, the shop can rapidly drill very small holes spaced 50 microns or less apart in metals less than 0.003-inch thick.
In one recent application, Potomac Laser machined conical micro-holes in control panels that would enable “invisible” backlighting. Because the limit of resolution for the adult eye is about 0.1 mm at 1 meter from the eye, the hole diameters on the user-facing side had to be smaller than 50 microns so that the hole patterns would be invisible to the viewer when the backlighting is turned off. When the light source is on, however, the display can show clear, sharp patterns using these micro-holes. The result is an unobtrusive control panel that displays needed information when relevant, but does not distract the viewer when it is not in use.
This diagram from Potomac Laser shows the conical micro-holes drilled through the display.
Metal fabrication company Wiley Metal says that laser cutting is its “go-to” process for small quantity work. It’s fast and accurate, and the cut edge is square and generally smooth. But laser cutting can’t handle every job. Reflective metals and textured surfaces can bounce the laser light back at the machine, causing damage. There are limits to the thickness of material that can be cut because of how the laser focuses to a point. Lasers also generate a heat affected zone that can pose problems for plastics, rubber and certain other materials.
In these cases, Wiley Metal turns to its waterjet. Waterjet cutting is slower than laser cutting, only about half the speed, but offers comparable accuracy. Like laser cutting, the cut edge is square and smooth. But unlike laser cutting, there is no heat-affected zone and nearly any material can be cut.
Recently I was invited to attend a talk on additive manufacturing hosted by the local chapter of the Product Development and Management Association (PDMA). My email invitation included a link to the Cincinnati PDMA Meetup group, which the organization used to set up and coordinate the details for this event.
If you’re not familiar with Meetup (I wasn’t), it’s a social network that allows users to create virtual groups based on interests that get together in the real world. Once you join a Meetup group, you can RSVP for its events, connect with other members and even contribute to crowdfunding to help pay for things like refreshments. It’s an interesting mix of social media and real-world networking and learning opportunities.
What struck me most about the PDMA Meetup was the free exchange of knowledge among the people at the event. Attendees ranged from manufacturers currently using additive manufacturing to those just learning about this technology or seeing it up close for the first time. The Meetup was a way for those newcomers to learn from others with direct experience, ask questions, and make contacts for follow ups. Maybe some of those relationships will lead to contracts or collaborations.
Surgery on the anterior cruciate ligament (ACL) in the knee is a complex procedure that demands precision and control. In order to repair or replace an ACL, the surgeon removes any remnants of the natural ACL and then attaches a replacement ligament (a graft usually taken from elsewhere in the patient’s body) to the tibia and femur. The positioning of the grafted ligament is critical, as it should accurately mimic that of the natural ACL.
To help make this precise surgery easier, orthopedic surgeon Dr. Dana Piasecki designed a two-part system consisting of a flexible pin (drill) and a guide for positioning the pin inside the knee. This guide is the key to a less invasive surgery, as it allows the surgeon to move and hold the pin without opening the knee or contorting it to place the new ligament.
Though 95 percent of the guide is made up of a simple shaft, the end of the device is the critical part. The shape of the neck is intended to follow the ligament’s normal path to ensure that it is placed at the right location and angle, and the tip is precisely sized to hold the 2.2-mm pin.
To machine this guide tool from a block would have required many setups with multiple angles and undercuts. Instead, Dr. Piasecki and his business partner Jim Duncan of DanaMed worked with Stratasys Direct Manufacturing to have the device manufactured with direct metal laser sintering (DMLS). This powder-bed additive process allowed the device to be built at the correct angle and build orientation to accommodate the critical features, without any machining necessary. Producing the guide additively also saved on material and reduced its overall cost, while enabling ongoing design changes.
Learn more about this device—including its design, manufacture and postprocessing—in this article from Additive Manufacturing magazine.
Machine tool distributor and systems integration expert Gosiger recently announced a new agreement to supply and service Stratasys 3D printers. The move is a natural advance for the company, whose customers are increasingly showing interest in additive manufacturing. However, the move is also strategic on the part of the 3D-printing equipment builder. Stratasys sees the future of its equipment not primarily among home or hobbyist users (though that might be a part of it) but instead in manufacturing facilities. The goal—for both Gosiger and Stratasys—is to help advance AM into applications out on the shop floor, and even into production.
As Josh Claman, chief business officer for Stratasys, put it: “The history of 3D printing is design and prototyping. The future is that, plus manufacturing.”
Claman addressed an audience at 3D4U, an event hosted at Gosiger’s Dayton, Ohio, headquarters shortly after the initial announcement was made. The June 14 open house and keynote presentation was a chance for Gosiger customers to learn about Stratasys technology as well as an opportunity for Stratasys to articulate its vision for additive manufacturing as a valuable tool for shopfloor applications as well as design and prototyping functions. Partnering with Gosiger provides necessary relationships and manufacturing expertise to help achieve that vision.
From Gosiger’s perspective, supplying 3D printing equipment is another way to serve its customers in addition to the machine tools, robotics, inspection equipment and complete turnkey systems it already provides. The company also sees great potential for using its own Stratasys machines to produce custom objects for its clients such as jigs and fixtures.
“As we expose our engineers to this technology, they are coming up with new ideas daily,” says John Haley, Gosiger CEO.
A number of sample components were on display during the 3D4U event, including some from Stratasys, but also many that were created by Gosiger employees following training on Stratasys 3D printers. These parts illustrate some of the services that Gosiger can provide with its new 3D printing capacity—and they may inspire customers to seek 3D printers of their own. A few examples of these applications are pictured below:
Gosiger frequently supplies machined custom fixtures for workholding and inspection. A metal CMM fixture such as the one on the left (holding the 3D-printed model stator) might cost upwards of $600 and take a week at a machine shop. The 3D-printed fixture (on the right) cost only $82 and was produced within a day on a Stratasys 450mc.
Robotic arms are another key component that Gosiger supplies, often as part of larger robot-tended cells. Custom grippers tailored to the customer’s application are commonly part of the package. Tools such as vacuum end effectors (like the one on the left) and jawed grippers (right) can be created and produced faster and more cost-effectively with a 3D printer than they can be machined. As an added benefit, they are also lighter than machined grippers.
1.3D-printed models can help speed the setup of CMMs and other systems. This model of an injection-molded vacuum cleaner component as well as the fixture it is resting on were 3D printed so that a CMM could be programmed before the actual parts arrived, reducing the quality control setup time from about a month to just one day.