Tap Testing is enabling Productive Machines Optimization

Tap testing, enhanced by Productive Machines technology, brings precision and efficiency to manufacturing. It empowers operators to optimize machine tool performance, reduce waste, and enhance product quality.

What is tap testing in CNC machining?

Tap testing, also known as impact testing, identifies structural dynamics by impacting a structure and measuring its response, in other words, tap testing tells us how flexible a machine tool assembly is.

In CNC milling, the tip of the milling tool is excited with a hammer to induce vibrations while collecting the measurement with an accelerometer.

The relationship between the force (input) and acceleration data (output) is the transfer function of the structure which is also called Frequency Response Function (FRF).

FRF represents the dynamic stiffness of the structure across the frequency spectrum and is used as an input for spindle speed calculator to calculate recommended spindle speed and depth of cut.

How to perform a tap test?

Productive Machines has partnered with Kistler, a lead supplier of a Tap Test equipment, to offer a complete hardware tap test kit. We have also partnered with Research Centres to provide tap test services or on-site/remote training for companies unfamiliar with the tap testing method.

What do we do with FRF data?

DigiTap, our tap test standalone software, calculates the FRF data from the tap test. FRF data includes natural frequencies, stiffness and damping ratios of the machine tool assembly.

FRF data feeds into the Spindle Speed Calculator to generate a stability lobe diagram. The user then knows to select a stable spindle speed and depth of cut under the stability boundary.

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