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Nick Katrov got his start in machining nearly 30 years ago by sweeping floors and cutting off materials in a Massachusetts shop after immigrating to the USA from Bulgaria at 19 years old. Eager to learn more about machine tools and the industry, he wasted no time demonstrating his willingness to apply what he felt was an innate ability to machine parts. Indeed, his chance came one day when the shop was flat out with work and shorthanded on machinists that were tied up on other projects. While waiting around near an idle machine, he took the bold initiative of writing a program to machine a part that was urgently needed by a customer. When the foreman returned to the shop he was as delighted as he was stunned to learn that the young Katrov had successfully written the program for the part all on his own, untutored. This experience would come to serve Mr. Katrov well throughout his impressive career, and especially so today, where at NDK Paragon he is the chief technical officer and sole machinist at a two-person shop in Oceanside, CA that manufactures complex 5-Axis parts for aerospace, semiconductor and medical industries. 

Good Things in a Small Package

It wasn’t only a desire to be a one-man operation in a machine shop that drove Mr. Katrov to start his own show. In addition to acquiring the machinist experience early on in his career, he also grew into management roles at well known machine tool manufacturers and distributors over the years where he interfaced with major industry players such as General Electric, Pratt & Whitney, Rolls-Royce and Bombardier, to mention a few. “It was a great run but I had enough of the corporate world, and I didn’t want the easy way out, so I decided to get back to my passion of cutting metal again,” said Mr. Katrov. So, he and his wife Tina Torabi, who is CEO and co-owner of NDK, moved to San Diego in 2017 to set up the shop. 

In NDK Paragon’s clean, well organized 3,800 square foot shop, which opened in 2018, the latest technology is utilized for all operations. There are three CNC machining centers. Two of these are Mikron 5-Axis models, one of them a 7-pallet system ideal for lights out manufacturing, and a third machine is a Doosan 3-Axis system. In addition to the CNC’s, NDK has a Hexagon CMM with full scanning capability. And with engineering and manufacturing under one roof, NDK also develops and machines prototypes, whether in one-off or in small batch production quantities. Being a job shop manufacturing primarily in high mix, low volume orders, precision, accuracy and reliability are paramount. “All of our applications require very fine surface finishes of better than 8 Ra, in addition to high dimensional and true position tolerances with tenths level accuracies” noted Mr. Katrov. 

Left The hyperMILL® CAM software suite from OPEN MIND Technologies enables a wide range of 5-axis machining strategies. Right – 5-axis roughing of a chamber.

hyper-Milled Strategies

Working on complex parts in this high precision world requires a robust, reliable CAM platform to drive key high performance 5-axis machining strategies, and Katrov has found this in hyperMILL®, a complete CAM software system developed by OPEN MIND Technologies with one postprocessor for maximum process reliability, minimized machining times and cost efficiency. “With our applications requiring full 5-axis strategies, we have successfully utilized most of the 5-axis modules in hyperMILL® such as contouring, tangent milling with barrel cutters, swarf milling and helical drilling” explained Mr. Katrov. “hyperMILL® makes the programming process seamless and easy no matter how complex the components are. The accurate part simulation extensively saves set up times and reduces scrap.” And reliability is no small matter in a one-machinist operation. “hyperMILL® is so reliable that I never need to worry about the software not working, so I can focus on the profusion of daily needs in the shop.” added Mr. Katrov. 

For example, utilizing the hyperMILL® tangent milling with barrel cutter strategies from the hyperMILL® MAXX Machining performance package have been more than an enabler for the shop. “Having these advanced 5-axis tool path capabilities has allowed us to manufacture very complex components with standard tooling which has in turn generated big cycle time reductions of up to 70%.” said Mr. Katrov. “And there are times when this tangent milling with barrel cutters feature provides the only way to effectively machine the required shape of the customer’s parts.”

5-axis cavity milling.

In addition to tangent plane machining, Mr. Katrov also relies on other hyperMILL® time and tooling cost savings such as 5-axis helical drilling that allows him to use regular end mills to helically drill large holes at high feed rates. A high precision surface module that enables NDK to mill fine surface finishes, and the advanced part probing cycles for the Heidenhain Control are also very helpful for Mr. Katrov’s operation, including the post processing capability. “ OPEN MIND postprocessing is clean and accurate. We have never needed to make manual edits to make the programs run properly.” 

The hyperMILL® CAM software suite enables a wide range of powerful 5-axis strategies for machining challenging geometries, free-form surfaces and deep cavities at maximum efficiency levels. Depending on the geometry and machine kinematics, a user can choose between 5-axis machining with a fixed tool angle, automatic indexing or true simultaneous machining. All toolpaths are generated fully automatically with collision checking and avoidance.

The performance package of hyperMILL® MAXX Machining offers three powerful modules for drilling, roughing, and finishing that make it possible to achieve the highest rates of machining productivity. 5-axis helical drilling opens large areas prior to roughing, using a standard cutter, and uses a 5-axis helical tool path to efficiently remove material and evacuate chips. For fast, reliable machining the roughing module includes cycles for milling spiral and trochoidal tool paths, as well as options that identify large inscribed rectangles or circles within components to optimally machine them with simple tool paths, completing the pocket by identifying the regions with remaining material. Dynamic feed rate adjustment according to actual cutting conditions constantly ensures milling at the highest possible rates. This results in optimal milling paths with maximum material removal. High-performance roughing of both prismatic and curved component faces with 5-axis techniques is supported.

Innovative algorithms in hyperMILL® CAM software ensure that a constant chip volume is continually removed. This delivers high utilization rates without exposing the tool to undue stresses, resulting in roughing speeds of up to 70 percent higher than conventional milling.

With hyperMILL® innovative 5-axis Tangent Plane Machining, OPEN MIND developed a unique ability for plane machining enabling cycle time reductions of up to 90 percent when used with conical barrel cutters. In addition, stepover widths of six to eight mm or more are possible with the large radii of conical barrel cutters, resulting in exceptionally smooth surface finishes and longer tool life.

Nick Katrov operating a CNC machine in his well-organized facility.

Growing While Knowing

Despite the challenge of the COVID-19 pandemic, NDK Paragon is rolling along and growing. Since the shop was set up in 2018, both sales and square feet have doubled. When asked if he would consider hiring new employees, Katrov said he is seriously looking into building an effective team, but he also glowed about the satisfaction of running a shop solo. “You’re in control of everything in the business and the product you make” said Katrov. “You need to make decisions fast and be willing to work 16-hour days, but nobody forced me to do it. I am proud of manufacturing beautiful parts and stand behind our quality”.

Article provided by Open Mind Technologies – Photos by NDK Paragon