Tactair Fluid Controls, Inc. (Liverpool, New York) had been looking for a better way to inspect the intricate internal features of its products. Tactair is an ISO 9001 certified designer and manufacturer of hydraulic controls for the aerospace and off-shore petroleum industries. Its product line includes valves, actuators, dampers and manifolds. Packaging, weight, and contamination resistance tend to be critical in these applications. As a result, maze-like flow path geometries, very fine surface finishes and precision metering edges are common. Such internal features defy easy inspection. Tactair used to resort to two main ways of inspecting internal features such as deep bores, ID grooves, seat edges, chamfers, and metering holes. The tried-and-true method of cutting a piece in half to look at the internal configuration wasted both time and materials. The other method was to check indirectly by filling the part with a molding compound, then pulling it out to examine it; but this also took too much time, and didn't work with all geometries. So Tactair decided to look for a borescope, one that would deliver sharp, clear images. The company was unsuccessful at first.
Tactair then decided to purchase a set of Hawkeye precision borescopes from Gradient Lens Corporation (Rochester, New York). The company can now inspect parts at each step of the manufacturing process more quickly and easily. By using the Hawkeye borescopes, Tactair has saved labor and materials costs. On one job alone, the company estimates the labor and materials savings paid for the scopes. The company also has found that engineers and machinists have begun using the Hawkeyes to optimize the setup process.
Tactair has found that the Hawkeyes have made inspections quick and easy at each stage of manufacturing. In the CNC turning and milling areas where bores, ID grooves and chamfers, and seat edges are done, machinists use the borescopes to look for tool marks and burrs. In the EDM area, where they reach deep into a bore to create a metering hole or oil passage, machinists use the borescope to check that they've placed the feature correctly and that the edges are clean and sharp. In the manual machining area, borescopes are used to check a feature's placement, surface finish, burrs and tool marks.
Surface finish is crucial to many of Tactair's internal features. During setup, it is also a key indicator of cutting conditions, telling machinists whether feeds and speeds, cutting tool geometry, and workpiece and tool rigidity are appropriate. The Hawkeye borescopes provide a fast and effective means of evaluating these conditions.
These borescopes come in a range of diameters and lengths. They offer either a straight-on view or a 90-degree view when used with a simple adapter.
The Hawkeye borescope lenses are made with rods of chemically treated glass called gradient-index or GRIN. Most glass lenses bend light only at their surfaces; because a GRIN rod bends light continuously along its entire length, engineers can simplify the design of optical systems. Fewer lenses do the work of many, reducing costs dramatically.
"On jobs where we used to set up, run, and then cut the first piece (in half) to see if everything was all right, we now can use the borescopes, so that's one production piece saved," says Bob Buttner, component manufacturing manager. "We do a lot of short runs, typically between 10 and 50 pieces—so this is important. But there's also the time savings. It varies anywhere from the few minutes it would take to pull the part off the machine and try to check it by another means—by a microscope or comparator, for example—to hours."
The Hawkeyes also have helped Tactair optimize the manufacturing process itself, by letting everyone from design engineers to machinists see what's really going on as tools cut through materials—giving them a clearer understanding of how materials behave under certain conditions.
Tactair personnel also employ the scopes in video viewing of internal features, using Hawkeye's video adapter with a camera and large screen monitor. Groups including engineers, machinists, and test technicians can examine parts together on the monitor to solve problems and improve processes. MMS