Overview

The RCD-9500 is an eddy-current crack detection system designed for a wide variety of fasteners, and flanged parts. It is capable of working as either a stand-alone machine, or mated with a Mectron Qualifier, LT, or MI8500 machine. The RCD-9500 includes an array of optical sensors to allow fully automated part separation, feeding, scanning, and acceptance testing. Instead of scanning moving parts on-the-fly, the RCD-9500 utilizes a pair of stationary motorized rollers to rotate the part in place, scanning the area of interest multiple times. This approach leads to greater accuracy and reduced signal noise without sacrificing speed.

 A high and low threshold can be set and altered to determine differences between good and bad parts. The usable frequency range of the Mectron EC600 instrument is 2 KHz to 5 MHz. All set-ups are easily saved internally in the instrument and can be recalled at a later date.

Eddy current probe

Eddy Current Explanatory Article

The system implements a differential eddy current probe for inspection, which uses two coils sending separate eddy current signals. The first coil is the test coil and the second is the reference coil. If the part is free of defects, then the eddy current signature of the test coil will always match the signature from the reference coil. If there is a crack or inconsistency in the part, the eddy current signal will register differently. This throws the two coils out of phase to each other and this inconsistency will be registered in the EC600 and recorded as a defective part.

Differential probes allow lift off variances and increased accuracy for consistently moving parts. The differential probe coupled with Mectron’s proprietary software allows for speeds of up to 180 parts per minute; making the RCD-9500 one of the fastest machines on the market.

The RCD-9500 is fed by a vibratory in-line feed system. When an optical sensor detects a part ready for scanning, a sprocket separator wheel pushes a single part onto the rotating rollers. The part will fall into the center of the rollers in line with the eddy current probe. Once the part is spinning, the differential eddy current probe begins to scan, collecting data for several revolutions and monitoring for defects. When the scan is complete, the rollers are driven apart, allowing the part to fall onto the pneumatically operated gate below, where it is either rejected or accepted.

Module Design

The separator and roller systems are completely modular; rollers and separator wheels can be custom machined to suit unique parts without altering any other tooling. The RCD-9500 is capable of inspecting many different types of parts including ball studs, wheel studs and a variety of other fasteners. The rollers can also be contoured to correct for cosine angles of the parts. The unique split gate system allows for high speed actuation when scanning small-diameter parts, while remaining robust enough to handle parts up to 10” long and over 1.5” diameter. The RCD-9500 is also fully compatible with the Mectron Qualifier, for dimensional verification.