New Touch Probe for On-Machine Measurement

CNC-ready instrument uses force analysis for speed and accuracy.

Advantages of On-Machine Measurement

The Heidenhain TS 740 touch probe. (Image courtesy of Heidenhain.)

The Heidenhain TS 740 touch probe. (Image courtesy of Heidenhain.)

Verifying the quality of machined parts is a challenge for manufacturing, and errors cost time and money to remedy.

Using on-machine measurement simplifies the diagnostic process for a number of common problems with machine tools. These problems can include erroneous feeds and speeds, buggy NC programs and improper tool and work offsets.

Periodically probing a workpiece minimizes the frequency and severity of these issues.

As an added benefit, operators can also monitor the degree of tool wear by periodically measuring select features of the workpiece as it is being machined.

This enables the operator to make an informed choice about whether a particular tool needs replacement or adjustment. Manufacturers can also use actual process data to plan maintenance cycles, rather than adopting an arbitrary timeline.

The quality control process also benefits from on-machine measurement.

Inspections take time, leaving machines standing idle for hours or even days. Opting for on-machine measurement streamlines that process.

Using Force Analysis for Touch Probing

The Heidenhain TS 740 touch probe attaches to a machine tool just like any other head.

It has an accuracy of < ±1 µm with 2σ repeatability at a probing velocity of 0.25m/min.

Cross-sectional view of the TS 740 touch probe. (Image courtesy of Heidenhain.)

Cross-sectional view of the TS 740 touch probe. (Image courtesy of Heidenhain.)

The probe measures the deflection of its stylus with pressure sensors between the contact plate and the probe housing.

As the TS 740 probes a workpiece the stylus is deflected, exerting force on the sensors. Since the sensors are arranged all around the stylus, the probe is accurate over 360 degrees.

The probe then transmits its signals via infrared, which is more reliable and secure than Bluetooth or WiFi. This makes it ideal for use on machines with automatic tool changers.

For more information, visit Heidenhain’s website.

Written by

Ian Wright

Ian is a senior editor at engineering.com, covering additive manufacturing and 3D printing, artificial intelligence, and advanced manufacturing. Ian holds bachelors and masters degrees in philosophy from McMaster University and spent six years pursuing a doctoral degree at York University before withdrawing in good standing.