Define the Measurement and Breakage-Check Scope
The application covers two Kunzmann BA 600 machining centers with Heidenhain TNC 426 controls. The initial process is electrode milling, with later expansion to complete parting-surface machining. Required functions are tool length, radius, and corner-radius measurement, plus tool-breakage checks after a tool change or a defined tool-life interval.
The Heidenhain TT 120 was identified as an in-workspace contact measurement system that transfers measured values directly to the machine tool table. The evidence also reports that tool-radius measurement can run with either a rotating or stationary spindle. Confirm these functions for the specific machine integration before purchase; the machine builder determines how the probe, control cycles, tool table, and PLC sequence work together.
Separate Measurement from Breakage Detection
| Method | Supported use | Constraint |
|---|---|---|
| Contact tool setter | Measure tool length and, where the machine cycle supports it, radius or corner geometry; perform presence or breakage checks. | Measurable geometry depends on probe access, tool shape, and machine-builder implementation. |
| Dedicated mechanical breakage sensor | Check whether a small, pointed tool such as a drill or small end mill still reaches the sensor. | A reported WFL implementation was limited to small, relatively pointed tools. Its detection result cannot be transferred automatically to a TT 120 installation. |
| Drive-load monitoring | Learn cutting load during an initial run, compare later runs, and stop the program when current cutting forces exceed the learned values. | This indicates a probable breakage rather than directly measuring the tool. Thresholds and control behavior are machine-specific. |
| Laser system | Tool measurement or breakage-only detection, depending on the selected system. | The project excluded laser measurement on cost grounds. Renishaw retrofit measurement and breakage-only laser options, and Blum laser measurement, were identified as alternatives without compatibility details. |
Resolve Product and Tool-Geometry Ambiguities
The evidence names Heidenhain TT 120, TT 122, and TT 130, but provides no compatibility matrix or explanation of their differences. Do not treat these identifiers as interchangeable. Obtain a machine-specific quotation and integration statement from the machine builder or manufacturer.
The stated cutter range is also ambiguous: the source describes the largest cutter as “30 R5” and the lower end as “1 ball,” without defining units or the complete tool designation. Record the actual diameter, corner radius, ball diameter, flute geometry, and permissible probing orientation for every tool family. A probe that measures a converging-tip drill does not necessarily measure a corner radius or complex milling profile with the same cycle.
Select the System and Integration Path
- Give the machine builder the exact machine and control combination: Kunzmann BA 600 with Heidenhain TNC 426.
- List each required result separately: length, radius, corner radius, tool presence, and broken-tool detection. Require the supplier to identify which cycle produces each result and where it writes the data.
- Clarify the TT model. The evidence begins with TT 120, later mentions TT 122, and asks about TT 130 pricing without establishing equivalence.
- Submit the real tool list, including the clarified “30 R5” and “1 ball” descriptions. Ask which tools can be checked while rotating, while stationary, or only with a dedicated breakage routine.
- Define when the CNC calls the check: after every tool change, after the configured tool-life interval, or both. Define the required response to a failed check, including program stop and operator indication.
- Compare the contact setter with a separate mechanical sensor, drive-load monitoring, or a breakage-only laser only after confirming machine compatibility and required measurement coverage.
The only price evidence is a historical statement from November 2004 that the TT 120 cost less than €3,000. It is not a current budget figure and excludes any unspecified installation, interface, PLC, cycle, or commissioning work.
Commission and Verify Breakage Detection
- Verify that each measured length and radius value reaches the intended tool-table entry and uses the correct sign and tool assignment.
- Run the supported measurement cycle for every approved tool geometry with the spindle state specified by the supplier.
- Introduce a controlled failed-check condition for each tool class and confirm that the CNC detects it at the programmed checkpoint.
- Confirm the machine response: the process must stop or branch as designed, identify the affected tool, and prevent unattended continuation.
- Repeat the test after a tool change and after the configured tool-life trigger. Do not accept a general claim of “100%” detection as proof for this installation; detection coverage is limited by tool geometry, probing path, sensor access, and the machine sequence.
Acceptance should distinguish direct mechanical detection from inferred drive-load detection. The former verifies contact or tool presence at a defined location; the latter reports a probable fault when cutting load exceeds learned behavior.
FAQ
Can a Heidenhain TT 120 measure tool length and radius?
The evidence reports direct transfer of measured data to the tool table and manufacturer-claimed radius measurement with a rotating or stationary spindle. Confirm the available TNC 426 cycles and corner-radius coverage for the Kunzmann BA 600 integration.
Is contact tool-breakage detection completely reliable?
No universal detection percentage is supported. Verify every tool geometry with a controlled failed-check test because probe access, tool shape, and the programmed measurement path determine whether the break is detectable.
When should the CNC run a tool-breakage check?
The stated requirements call for checks after a tool change, after a defined tool-life interval, or both. Commission each trigger and confirm that a failed check stops or redirects the process as designed.
