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Engineering Resource

Engineering Resource

A measured part is a known part. Here is how coordinate measuring fits into our process, why temperature matters, and what documentation you receive.

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What a CMM actually does

A coordinate measuring machine touches the part with a probe, records the exact position of many points, and fits geometry to them — a plane, a circle, a cylinder. From those fitted features it calculates size and geometric tolerances such as position, flatness and concentricity.

That matters because a caliper can confirm a diameter but cannot tell you whether a hole is in the right place relative to a datum. For anything with a position requirement, the CMM is the only honest answer.

Why temperature control matters

Every material changes size with temperature — steel by roughly 12 µm per metre per °C, aluminum about twice that, and engineering plastics far more. If a part is measured hot, straight off the machine, the numbers describe a size the part will never be at rest.

That is why tight work is measured in a controlled environment, and why stress-sensitive parts such as machined PEEK are measured only after the material has fully relaxed. The measurement should describe the part as it will be in service, not as it was at the spindle.

When we inspect

  • First article inspection (FAI): a new or revised part is fully measured against the drawing before series release.
  • Critical dimensions: every drawing dimension marked critical is measured, not sampled.
  • Batch checks: recurring production is checked at intervals to confirm the process has not drifted.
  • Customer-specified: where a drawing or quality plan names a measurement, it is done as named.

The documentation you receive

Dimensional inspection reports, first article inspection reports where required, EN 10204 3.1 material certificates and full batch traceability — so the part can be traced back to its material and its inspection record. Downloadable evidence like this is what gets a supplier through a customer audit.

Why in-house metrology matters

Our Zeiss CMM and material spectrometer are in-house, so dimensional and material verification do not wait on an outside lab and results come back inside the same production loop. When a dimension is marginal, that speed is what allows the process to be corrected before more parts are made.

FAQ

Frequently asked questions

A coordinate measuring machine touches the part with a probe, records many point positions and fits geometry to them, then calculates size and geometric tolerances such as position, flatness and concentricity.
Because every material changes size with temperature. Measuring a part hot describes a size it will never have at rest, so tight work is measured in a controlled environment.
A full measurement of a new or revised part against its drawing before series production is released, so both sides agree the process produces a conforming part.
Dimensional inspection reports, FAI reports, EN 10204 3.1 material certificates and batch traceability, depending on your requirements.
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