coolEX®, coolEXact® and coolEX® LM form a common technology family for honing on machining centres and lathes. All three systems use coolant pressure for hydraulic tool expansion and the existing machine spindle for rotation and stroking. They differ in how the finished size is determined and how the process is stopped or controlled.
coolEX® expands the honing stones hydraulically during machining and is particularly suitable for short finishing processes in well pre-machined bores. The finished size remains relative to pre-machining. coolEXact® adds a defined size shut-off to the coolEX® principle. coolEX® LM combines hydraulic expansion with DPMS 3.0 air gauging and controls the process using actual measurement data.
| coolEX® | coolEXact® | coolEX® LM | |
|---|---|---|---|
| Tool type | Hydraulically expanding honing tool | Hydraulically expanding honing tool with size shut-off | Hydraulically expanding honing tool with air gauging |
| Honing-stone expansion | By coolant pressure | By coolant pressure | By coolant pressure, controlled by measurement data |
| Size control | Finished size relative to pre-machining | Defined size shut-off, typically below 10 µm | Closed control loop, typically below 3 µm |
| Pre-machining allowance | For small and consistent allowance | Larger allowance possible; variation should remain limited | Larger and more variable allowance possible |
| Process control | By machining time, coolant pressure and tool specification | By adjustable size shut-off | Closed loop of measuring, honing and control |
| Machine integration | Machining centre or lathe with through-tool coolant supply | Machining centre or lathe with through-tool coolant supply | Machining centre or lathe with DPMS 3.0 |
| Typical application | Finished surface, cross-hatch and short cycle time | Defined size control with stable pre-machining | Tight finished tolerance with more variable pre-machining |
With coolEX®, the honing stones are expanded hydraulically during machining by coolant pressure. The coolant also provides process cooling and chip removal directly at the contact area between the honing stone and the bore. Rotation and axial reciprocation produce the classic cross-hatch at the defined honing angle.
The machining result is influenced by machining time, coolant pressure, tool design and honing-stone specification. The finished size remains relative to pre-machining. The technology is therefore particularly suitable when a small, consistent honing allowance is available and the main objectives are the finished surface, cross-hatch and a short cycle time.
The technology is available for through and blind bores. Special versions such as coolEX® 2 provide double expansion for specific machining tasks.
coolEXact® is based on the hydraulically expanding coolEX® technology and adds a defined size shut-off. The honing stones are likewise expanded by coolant pressure. When the set size is reached, the size shut-off stops further machining progress.
This compensates for pre-machining variation much more effectively than a purely time-controlled coolEX® process. coolEXact® is suitable for larger machining allowances and defined size control below 10 µm, provided that the initial allowance does not vary substantially.
The system is available in three size ranges: mini for approximately Ø5–30 mm, midi for approximately Ø25–50 mm and standard from approximately Ø48 mm. It can be used on machining centres and lathes with through-tool coolant supply.
coolEX® LM combines active hydraulic expansion with DPMS 3.0 air gauging. The tool measures the bore during the process, evaluates the results and adjusts expansion and the machining sequence using the measurement data.
The control loop comprises measuring, adjusting and honing. This allows both final size and cylindricity to be corrected with high precision. With a suitable machine and process configuration, dimensional deviations below 3 µm can be achieved.
coolEX® LM is particularly suitable for automated manufacturing processes, tight tolerances and components that require documented, measurement-based machining.
| Manufacturing task | Recommended technology | Reason |
|---|---|---|
| Finished surface and cross-hatch with a small, consistent allowance | coolEX® | Hydraulic expansion and a short, time-controlled finishing process |
| Size correction with defined shut-off | coolEXact® | The size shut-off stops the process at the set finished size |
| Tight dimensional tolerance and measurement-controlled correction | coolEX® LM | Air gauging and active expansion form a closed control loop |
| Different bore diameters within the same machine concept | coolEXact® | Mini, midi and standard sizes cover a wide diameter range |
| Automated correction of size and cylindricity | coolEX® LM | Position-specific measurement data can directly influence machining |
coolEX® provides hydraulically expanding honing with process control through time, coolant pressure and tool specification. coolEXact® adds a defined size shut-off to this basic principle. coolEX® LM combines hydraulic expansion with DPMS 3.0 air gauging and enables a closed-loop, measurement-controlled honing process.
The appropriate technology depends on pre-machining quality, tolerance requirements, the required geometry correction and the degree of machine automation.