Guitar maker increases production efficiently by using CNC software to program detailed routing jobs

Modern Machine Shop, Nov, 1994

Ovation Instruments, Inc. produces 350 guitars a week. In the past, detail work was done by hand, using a jigsaw, files, and carving tools. But as the company experienced greater demand for its guitars, it needed a way to increase production efficiency. Using a CNC machine for cutting and routing, along with Mastercam, the PC-based CNC programming system from CNC Software, Inc., Tolland, Connecticut, has proved to be an effective solution. Once the geometry has been imported or created in Mastercam, the software generates contouring and roughing paths for the CNC machine almost automatically. Once the CNC machine is set up, it cuts as many as 40 inlays in 20 minutes, relieving employees of repetitious work and freeing them to perform other tasks. The efficiency of the new system has carried over to custom guitar detailing, enabling Ovation to lower the cost of this service and make it available to more performers.

Ovation Instruments has come along way since founder Charlie Kaman started making guitars in a helicopter blade factory more than 25 years ago. His commitment to build guitars using the latest aerospace technology and traditional New England craftsmanship set the stage for rapid growth. Many of the 130 employees in New Hartford have been with the company since its beginning, and they are widely regarded as some of the best guitar makers anywhere.

In the past, pre-cut mother of pearl inlays were purchased from Germany; all other detail work was done by hand at the Connecticut facility. Someone would first draw the wood figures at twice their size and then reduce them using a Pantograph machine. Then a steel master template was produced. Rough cutting was done using a small jig saw, and the pieces were refined using a handsaw and special file. These steps tool several days, not including cutting cavities in the fingerboard or peghead; a process that took several more days. Not only was this manual process time-consuming, but it was also tiring. Employees could only concentrate on it for a few hours at a time, then they would have to stop and switch to another task. And every time the company came up with a new inlay design, a toolmaker had to make a new steel master template.

In an effort to streamline this process, Ovation began looking into CAM. The company's corporate parent is in the aerospace industry, and a number of its other divisions use Mastercam. Experienced users told engineers at Ovation that the system was user-friendly, easy to learn, and able to create 2D and 3D geometry, as well as import AutoCAD geometry easily. These recommendations turned out to be correct.

Since purchasing Mastercam and a Techno CNC router, Ovation has automated the production process for fingerboard inlays and peghead logos. The new production process for a typical fingerboard inlay goes as follows: an engineering technician draws a reference print of a new inlay using an existing CAD system. The file is then imported into Mastercam where a template of the CNC table has already been created. This template includes all the different fixtures that will be used in production, as well as representations of different size strips of maple. When the inlay geometry is imported, it is oriented into the correct cutting position using the software's geometry manipulation capabilities. The next step is defining the cutter path. The user specifies the tool, the cutter size, tolerance, feeds, and speeds. The software then generates the outer path. All this is done for one inlay only, but the software allows the user to program the machine to cut multiple inlays, usually 20 to 30 from one strip of maple.

In addition to the decorative woodwork, Mastercam is used in a number of other ways. For example, Mastercam's full 3D CAD functions are used to model new detailing designs.

Mastercam is well suited to 3D work because in addition to creating 3D geometry of its own, it has the ability to read and modify IGES data files containing NURBS and parametric surfaces.