Duonetics Corporation – Getting The Balance Right For 57 Years

By December 17, 2020Articles

Duonetics Corporation of Corona, Ca. originally came online as balancing shop in Los Angeles. It was the brainchild of Charles A. Pernice who leveraged his experience into building a business that would thrive for decades to come. Charles was a flight engineer on B29 bombers in WWII and in training to be a fighter pilot before the war ended. He was also a veteran of the Air National Guard, having served on the east coast as an aircraft mechanic that included Presidential Aircraft during the Eisenhower administration. After his service Charles cut his teeth selling electronic balancing vibration analysis machines on the East coast, before moving his family west. “My dad got tired of the cold New York winters, packed us up and started a new career in California,” tells Robert J. Pernice, Duonetics Corporation’s second-generation president. “He worked for a company out here that revolved around balancing, so when he set out on his own in 1963 balancing was at the forefront of the operation. Fifty-seven years later it still plays an important part in what we do.”

Charles saw the need for a company offering balancing services to the aerospace and their related industries. He also recognized that the level of precision needed required top of the line machine tools to support the high-tech balancing customers. “We always believed in having the best machine tools,” continues Robert. “I started sweeping floors when I was ten years old and have run every machine to come through these doors. Originally, the mills and lathes were just used to create fixtures, tooling and things of that nature, but through the years we have evolved into a high-tech job shop with extensive capabilities that include balancing.”

When balancing a part accuracy is critical, in fact it is the foundation of balancing. There is no fudging precision when a part is designed to spin at thousands of RPMs. A balanced part rotates on a center line. If there is a little warp or the fixture isn’t perfectly aligned the part is running eccentric when you balance it and you can’t do a good job. Actually, you do a poor job and will make it worse than when you got it. “When a customer brings in a part for balancing our first step is to figure out the best way to fixture it for optimum accuracy and precision,” explains Robert. “Most parts are straight forward, but when it isn’t, the customer relies on our near 60 years of experience. Parasitic mass is something that frequently comes into play in precision balancing. In other words, it is the tail wagging the dog. You have a part that weighs 3 ounces, but the balancing arbor can’t outweigh the part by a factor of multiples. Otherwise, the amount of mass that you are trying to analyze is overcome by the weight of the tooling. With 6 balancing machines on our floor, we can efficiently process parts weighing just a few ounces up to 1500 pounds of rotating weight. Our equipment is all American made Hofmann brand balancers. Hofmanns are acknowledged as some of the best in the industry for their accuracy and reliability. Each machine is calibrated to aerospace standards to maintain accuracy and controlled by our AS9100 QMS.”

Duonetics Corporation operates “lean & mean” with 7500sq.ft. of manufacturing space at their disposal. Five full time employees split duties between the mills, lathes, balancing, programming and QC. Everyone is cross trained, giving the company an agility rarely seen in shops this size. “We are very well equipped and highly maneuverable,” touts Robert. “The diversity of our equipment gives us nimbleness and adaptability to tackle nearly anything. We have everything from the basic saw up to the most sophisticated 5 axis machining equipment money can buy, a DMG Mori DMU85. We have turning centers with live tooling and Y axis, 3, 4 and 5 axis milling machines. Our machines are larger than most shops of our size. We can pretty much handle anything you throw at us up to about 3’ in diameter.” 

Duonetics’ extensive milling department is made up of the best names in the industry like Kitamura, Yama Seiki and DMG Mori. The stars of the show are their two DMG Mori 5 axis milling centers. Their first one was purchased about ten years ago, a DMG DMU60 Monoblock. Robert liked it so much that he added a DMG 85 Monoblock a few years later. Both DMGs offer 18,000 RPM ceramic bearing spindles, Renishaw or Heidenhein on-machine probing systems, Blum lasers for tool life management, and they have self-calibration. Sitting next to the DMGs is a Kitamura Mycenter H300 4 axis palletized horizontal with 100 tool capacity and two Yama Seiki BM850 vertical milling centers with 4th axis capabilities. Duonetics’ turning department includes a brand new DMG-Mori NLX 3000/700, to go along with their Nakamura Tome Slant 1, Nakamura Tome TMC II, and a DMG CTX 510 with live tooling for production work. They also have a variety of support equipment including welding, honing, and laser engraving. “Everything that gets balanced has to be manufactured, and what we’ve found over the years is that having the ability to do complex parts feeds the balancing business and vice versa,” details Robert. “They complement each other perfectly. A customer might come to us for a balancing job and not realize that we also have 5 axis capabilities. Being able to handle everything internally and hand them back a machined, balanced, assembled part is a huge value for customers.”

Duonetics Corporation has a wide range of customers in a variety of industries. If it requires precision made complex parts, exotic materials, or both; chances are they have it covered. “We run the gamut when it comes to our customer base,” tells Robert. “Anything from general commercial to aerospace and everything in between. Oil & gas, chemical, pumping, automotive. We have a variety of parts on the Saleen S7 production road car as well as their race car. Of course, our roots are steeped in aerospace, so much of what we do falls under that category with customers like GE Aviation and Lockheed Martin. We are AS9100 RevD certified and just got re-certified with zero findings.” Duonetics has an incredibly low defect record with their customers. Most of the parts they machine are extremely high value components; scrap is rare as a result of their inspection equipment and practices. “We are very proud of our inspection lab,” continues Robert. “We take quality seriously and it shows. Our customers know our reputation for quality, and they keep coming back for good reason. We utilize a Starrett CMM and a portable laser scanning Romer Arm to insure everything is up to spec and NIST traceable.”

“There is no limit to what this shop can make,” concludes Robert. “Duonetics is not a turning house, not a milling house, not a balancing house, we are all those and much much more. I hate to classify what it is we do, but I guess high precision job shop would fit the bill. We have really advanced capabilities that other shops typically don’t. For our size it would be hard to find a company with similar attributes and technology. Because of our skillset and equipment we take on a lot of work that others don’t want to mess with. When a customer comes in our door, they can be 100% confident that we are going to deliver exactly what they asked for, if not better.”