The machine bed, column, and spindle housing are in the same thermal state. The ballbar circle is clean; the micron reads “spot on”.
In titanium and nickel, most of the heat does not leave with the chip; it transfers to the tool and the machine bed. If thermal compensation is weak, a dimension that is accurate in the morning may deviate in the afternoon. This is often not a tooling error, but the machine's inability to handle the heat.
A familiar scene in the workshop
The operator runs the same program. The CMM says “OK” in the morning. In the afternoon, the same part is out of tolerance. The tool hasn't changed. The fixture hasn't changed. The only thing that has changed: the temperature of the machine.
The machine bed, column, and spindle housing are in the same thermal state. The ballbar circle is clean; the micron reads “spot on”.
Cutting heat + drive heat spreads to the machine bed. The axis offset drifts. Same program — different dimension. Scrap is no “surprise”.
Why titanium / nickel?
In steel, most of the heat leaves with the chip. In Ti-6Al-4V and Inconel, heat is trapped in the cutting zone; it escapes to the tool and spindle, and from there it seeps into the column.
Hard alloy = higher torque, longer contact. The spindle and ballscrew generate their own heat. The machine bed heats up from both the outside and the inside.
An aerospace / defense part is not a 40-minute “short job”. Thermal drift accumulates during passes that take hours — a single measurement moment is misleading.
What should the machine bed do?
A rigid cast iron or mineral composite bed does two things: it dampens vibration and slows down heat. Resonance is shifted; ambient and process temperatures do not disrupt the geometry all at once.
How to detect it?
ISO circularity when the machine has cooled down overnight. This is the “advertised accuracy” — the green ring you see on the sales slide.
The same test, after 2–3 hours of superalloy cutting. If the deviation has grown, the problem is not the toolpath; it is the thermal chain.
The same critical dimension in the morning and evening. If the difference eats up half of your tolerance budget, machine selection is reopened.
Result
In Wiesser machines, a rigid bed, cooled drive, and sensor-based compensation are used to hold the dimension throughout the shift in titanium and nickel machining. Send us your part and process information; let's evaluate the thermal risk together.
The Art of Milling
Provide your material, cycle time, and critical tolerance information. Let's evaluate thermal deviation together during the process assessment.