Tap Testing

  Using the CATT

  Sample Data
   & Images

  Data Analysis





 Advanced Structural Imaging, Inc.
 1501 Duff Avenue, Ames, IA 50011

Computer-Aided Tap Tester (CATT)

The Semi-Automated Inspection Cart

The semi-automated inspection cart was developed to produce evenly-spaced, repeatable taps on a part surface. The inspector grips the cart in a manner similar to a computer mouse and pushes the cart along the surface of the component being inspected. The cart is pushed along a series of straight lines on a template attached to the surface of the component. Data is feed into the computer with each tap produced by the cart until the end of a line has been reached. At the end of a line, the operator picks up the cart and moves it to the next line. A button is clicked on the front of the cart to inform the computer that the operator is ready to scan the next line. This is repeated until the entire area has been tapped.

The device uses magnets to both raise the tap probe and to assist it in its motion toward the surface. Figure 1 below shows the tap probe being raised by magnets. (Note that the like poles of the magnet are opposing each other.) The raising process continues until the travel of the probe is physically stopped (Figure 2). As the rotating magnet passes by the constrained magnet, the direction of the force acting on the probe is reversed and the probe is “thrown” down (Figure 3). The instrumented probe then impacts the surface, creating a tap (Figure 4) and the impact time is measured. The cycle then repeats itself when a different magnet on the rotating wheel raises the probe. (Only one magnet is shown on the wheel.)

View Video of Cart (14 Seconds)

(MPG, 2.2MB)    (RM, 1.1 MB)
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