Digital optical comparators are vital inspection and measurement tools for making sure that machined parts meet CAD specifications. The latest model in the market is the VisionGauge 700 Series from VISIONx Inc. of Pointe-Claire, Que., Canada, an automated system with five axes of motion — X, Y, Z, B (rotary), and A (tilt) — that allow parts to be inspected from all sides and angles.
Officially launched on June 11 at Metal Storm, a Methods Machine Tools open house in Sudbury, Mass., models in the VisionGauge 700 Series are designed as drop-in replacements for comparators with 24- and 30-in screens, says Patrick Beauchemin, president of VISIONx, in discussing features of the inspection system at a presentation during the event.
Methods Machine Tools is the official distributor of the VisionGauge 700 Series. A ThomasNet News report on activities at the open house will appear in the upcoming weeks.
The VisionGauge 700 Series is targeted at complex parts in markets such as medical, aerospace, power generation, and automotive, though it can, of course, inspect any produced piece, including plastics. One application Beauchemin cites, for example, is the inspection of cutting tools, whose complex geometries, tight tolerances, and small production lots are a good fit for the comparator.
The new machines use a Windows 7 operating system and run essentially the same VisionGauge software as the company’s 3-axis 300 and 500 Series systems, though the OS is adapted for 5-axis inspection. The new comparators achieve 3D mapping across the entire work envelope and permit quick and accurate part inspections, Beauchemin says. The models are compact and robust enough for shop-floor use, and two operators can share one system for greater productivity without affecting accuracy.
Operating features include CAD Auto-Align, the company’s proprietary tool that automatically aligns CAD data with a part to rapidly determine if it is within spec. Combining this with another feature, Auto Pass/Fail, allows an operator to automate inspections.
After loading a part in the fixture, a bar code is scanned. This automatically runs a part-specific program that accesses the part’s CAD file, automatically aligns the file to the part, and generates a pass/fail result that is sent to an external application such as an Excel spreadsheet.
The 700 Series units come in horizontal and vertical models (horizontal models account for most of VISIONx’s sales in the 300 and 500 Series). The difference between the horizontal and vertical models is basically in the fixturing each uses.
According to the company, features of the 700 Series include comprehensive data collection and reporting, easy programming, fast and intuitive operator reviews, and a high depth-of-field capability that improves the inspection of complex parts.
The machines provide clear, high-resolution imaging, Beauchemin says. Illumination is by LEDs, which are engineered to provide consistent levels of multi-angle and multi-quadrant illumination through 10 years of continuous use. The new series additionally has extensive measurement tools, a user-friendly operator interface consisting of a joystick and the bar code reader, and the ability to quickly reexamine out-of-spec areas.
The standard travel in the X, Y, and Z axes is 12 in (300 mm). The range of motion in the B (rotary) axis is 0 to 360 deg, and A-axis (tilt) range is -90 to 90 deg.
All axes have closed-loop encoder feedback. Encoder resolution in the X, Y, and Z axes is 0.25 micron, and 0.005 deg in B- and A-axis operation.
The 700 Series has a 20-times equivalent optical magnification. Its working distance is 9 in, while depth of field is 1.8 in and field of view is 1.7 by 1.2 in. The stated accuracy of the optical system exceeds 4 microns (+/-0.00015 in).
The series machines come with a System 3R Macro Chuck mounting unit but can be equipped with other types of fixtures. The software automatically corrects for chuck offset, fixture height, and the fixture’s center-of-rotation offset in the X and Y axes.
Models can, moreover, be used as part of a turnkey operation.
One notable feature is the unit’s ability to inspect drilled holes produced from electrical discharge machining (EDM), such as those in aircraft components that are used for cooling. The 700 Series verifies and accurately measures the location of every round or shaped hole from all sides and angles.
A machine can inspect one EDM hole at a time or examine multiple holes simultaneously. It provides uniform inspection of holes in coated or uncoated parts. Using adaptive feature-detection software, a 700 Series comparator also detects and locates holes on surfaces with different levels of reflectivity and at different viewing angles. It compensates for surface features such as burrs and splatter, and the software disregards chipped coatings while inspecting drilled holes.
The comparators can be equipped with a mounting system that allows parts to go from an EDM machine to inspection without refixturing. Beauchemin says a machine can be programmed to report offsets in X- and Y-axis measurements and feed this data to an EDM unit for drilling correction.