Roundness & Flatness Testing

Professional Instruments Company’s precision sub-contract manufacturing business is built around our ability to produce precision parts to tolerances of less than 100 millionths of an inch (.000,100”). Our customer base provides us with new challenges in part holding, machine accuracies, and inspection tools nearly every day. Professional Instruments Company had to develop many of the tools and techniques used in our shop because the tools readily available have not been up to the task. We offer for sale a few of these important developments.

Roundness testers are a critically important element in development of precision-tolerance capabilities. Our BLOCK-HEAD® air bearing spindles enable us to have millionth-inch-accuracy inspection stages strategically placed throughout our manufacturing facilities. The ability quickly and accurately to measure roundness, parallelism, and flatness on the shop floor as well as in the inspection department gives us a distinct advantage over our competitors. We feel strongly that a BLOCK-HEAD® air bearing spindle with a permanently attached, assembly-ground fixture plate is a fundamental tool for millionth-inch inspection. Our roundness tester features a true-running surface with an optional tip/tilt table. The ability to have a fixture surface referenced to a perfect axis of rotation in a shop environment provides a fantastic array of advantages. Roundness can be measured by placing parts on the fixture plate. Parallelism is gaged using ordinary surface gage technology. Placing flat parts eccentric to the axis on top of the plate provides for flatness explorations. Our roundness measuring components provide the ability to take roundness testing out of the lab and put it on the shop floor where it belongs!

Precision flatness measurement requires a reference plane to compare geometries. Professional Instruments Company uses a variety of flatness measurement equipment in our shops. Surface plates and surface gages are used. We picture here a vacuum preloaded air bearing surface gage to compare one surface to the other. Professional Instruments Company builds larger scale vacuum preloaded air bearing slides with precision tilting top stages and a bridge-style indicator mounting system. Each of our shops has multiple versions of these stages, allowing our toolmakers access to millionth-inch repeatability on a shop-floor-hardened flatness measurement system.

While the measurement systems described here are not stock items, they are available on a custom-designed basis.