When a long-time customer came to Northwood Industries, Perrysburg, Ohio, with a challenge to redesign and make a part for one of its commercial paint spray guns, the company was pretty sure they had it covered. Northwood Industries is an ISO 9001:2015-certified supplier of precision-machined component parts, mechanical assemblies and engineering design services to manufacturers throughout North America, Europe and Asia.
Today, Northwood Industries occupies a 24,000 ft2 (2,229 m2) manufacturing facility just outside Toledo, Ohio. It operates with a full complement of CNC milling and turning machines and multiple seats of Mastercam CAD/CAM software from CNC Software Inc., Tolland, Conn. Its roster of 37 employees includes 25 skilled tradesmen and apprentices, two design engineers and several support team employees.
Northwood Industries serves a variety of customers but half of its work comes from two major industries: coatings and solar energy. The company provides its customers with machined parts with fairly tight tolerances. The majority of its work is ±0.005″ (0.13 mm). However, some parts require dimensional accuracy to 0.0001″ (0.003 mm).
One of its largest and oldest customers, a manufacturer of fluid coating equipment, approached Northwood Industries in early 2018 for a solution to a modern-day problem. It needed to modify the trigger part of one of its commercial paint spray gun handles into a “three-finger trigger” for better fit and handling for smaller hands.
Initially, the requirement was for three new trigger parts to use as samples in order to get the parts stamped-out. A couple of months later, however, the customer—eager to get the new gun trigger out into the field—came back to Northwood Industries, asking them to make 50 of the new gun handle trigger parts out of aluminum.
“When we initially programmed the trigger part,” said Kevin Carter, turning operations leader at Northwood Industries, “it was the first of its kind for us, and it took me six hours to machine just that one part. But by the time the order for 50 parts came in, we had upgraded our software to the latest version of Mastercam 2019, figured out how to better utilize the software, and reduced the job from two operations to one. We started with the Model Prep feature, but it was the Dynamic Motion technology that really helped us achieve shorter lead time and faster production time. Of course, OptiRough made it easier to polish the part right there, eliminating the finishing step. We got the job done and out the door in no time. Everyone, especially our customer, was happy about that.”
Dynamic Milling uses proprietary algorithms programmed into the Mastercam software to automatically detect changes in the material as the tool cuts through. The tool remains engaged with the material, minimizing air cuts and allowing the machines to be pushed to full capacity. Depending on the speeds, machining time can be cut between 25 and 75 percent. The OptiRough toolpaths use Dynamic Motion but in a more precise way. The cut uses the entire flute length of the tool, but a small percentage of the tool’s diameter on the first cut, followed by several successive shorter cuts that bring the part into the desired net shape.
According to Miller, Northwood Industries now takes every opportunity to consolidate manufacturing operations so that more can be performed at the machine during a single setup. The reduced set-up time and improvement in manufacturing productivity have been remarkable. Miller identified two features of Mastercam—the Dynamic toolpaths and Verify, Mastercam’s simulation function—that have given Northwood Industries valuable competitive advantage when it comes to meeting the quick turnaround needs of its customers.
“Mastercam allows us to prep a model without really checking anything. If the model’s right, we put a toolpath to it and start cutting as soon as we’re done programming,” Miller said. “As long as it looks good in Verify, it’s going to look good on the machine. The idea is to get the spindle running. Mastercam is a tool that helps us get our machine tools operational. Our customers aren’t buying programs. We don’t sell programs. We sell parts. With the help of Mastercam 2019, we’ve reduced cycle time by 5 to 10 percent.”
According to Miller, in addition to fast turnaround, the quality of Northwood Industries’ machined products has also improved “based on the toolpath selections that are made and the way that the parts are now machined.”
The software’s Lathe package is producing dramatic time savings in manufacturing another part for spray guns, a component made from titanium, according to Carter. “When combined with C/Y-axis machining, the lathe can cut turned parts quickly and accurately. In addition, when combined with the software’s Mill solution, programmers get the benefits of mill-turn machining. When cutting 1,000 tiny serrations, or ticks in the 2.5″ [63.5-mm] circular part, the efficiency makes a huge difference,” Carter said.
“If we had to program making those serrations using long-hand, we’d have been there all day. Now, instead of turning it all in the lathe, then sending it over to the mills to have the serrations machined, we’re able to serrate the part in the lathe.” What was formerly a five-stage part is now done in three stages. “Plus, we’re able to hold it more accurately.” Carter noted that these components are balanced parts that run at 50,000 rpm. “Having everything machined in the final stage helps control the balance of the part,” he said.
The software’s Dynamic Milling feature also benefits Northwood Industries in other important ways—like extending tool life up to 10 times. “With Dynamic Milling, you’re taking three times the diameter cut and you’re using the whole side of an end mill. As long as it’s programmed right and you don’t break the end mill, it lasts ten times longer than taking a-hundred-thousandth-step cut and burying the end mill back and forth. No more chewing up the corners of the end mill then sending it out to be re-sharpened,” Carter said.
Northwood Industries places enormous value on its 20+ year relationship with FASTech, Findlay, Ohio, a third-party post-processor applications developer and Mastercam Reseller and CAD/CAM solution provider. “They have been writing and fixing all the posts for our machines for years and providing software training,” said Miller.
Looking to the future, Northwood Industries’ new commitment is to a redesigned in-process inspection plan that places greater emphasis on inspection at the bench level for each operation, and is less dependent on the inspection room.
“During machining cycles, we’re making sure the parts are being inspected through-out the process,” Carter said. “Inspection points are customized based on the quantity being produced, the value of the part, or the complexity. If we’re making one part, the inspection count is one. If we’re making 100, maybe it’s every 50. If it’s more complex, we’re checking every five or 10. That’s unique to our business.”
“We’re trying to adhere to a quality inspection process during the machining cycles or during those steps,” said Miller. This process places the responsibility of machining accurate parts where it should be, with the machinist, and allows us to address any quality issues early on. As
a result, the number of quality issues identified in the inspection room during final inspection has dropped significantly.”
For more information from Mastercam – CNC Software Inc., go to www.mastercam.com, or phone 860-875-5006.