Why in-house metrology shortens a qualification timeline
Qualifying a new machining supplier takes longer than machining the first part. The delay is rarely the cutting — it is the loop between measuring a feature, deciding whether it conforms, adjusting the process, and measuring again.
The outsourced loop
A shop that sends parts to an external metrology lab runs that loop at the lab's pace. A single iteration is a courier out, a queue, a report back, and an interpretation call if anything is ambiguous. Two or three iterations on a first article is normal. The machining time is hours; the loop is days.
The second cost is subtler. When inspection is expensive and slow, it gets rationed. Fewer in-process checks are made, problems are found later, and the correction is bigger when it comes.
What changes when the CMM is in the building
Iteration collapses to the same shift. A feature can be cut, measured, and the offset corrected before the setup is broken. Datums stay established.
In-process inspection stops being rationed. Checking a critical feature mid-run costs a walk across the shop, so it gets done.
Characteristic accountability is not a scheduling problem. An AS9102 Form 3 on a part with several hundred characteristics is a long measurement session. Owning the machine means it is planned around production rather than around a lab's calendar.
The measurement conversation happens directly. When a result is marginal, the person who machined the part and the person who measured it are in the same building, looking at the same fixture.
What "in-house metrology" should mean
The phrase is used loosely. It is worth checking what is behind it:
- A CMM with a published E₀,MPE expression and a temperature-controlled room — not a machine standing on the shop floor next to a machining centre
- A height gauge for fast dimensional checks that do not warrant a CMM programme
- A video measuring machine for non-contact work on features that a touch probe would deflect or cannot reach, and for GD&T analysis
- Calibration records for all of it
RAVIS runs a Mitutoyo CRYSTA-Apex V CMM in a temperature-controlled inspection room, a Mitutoyo LH-600 linear height gauge with 0.1 µm digital step, and a video measuring machine for optical and GD&T work. How to read what a CMM specification actually promises is covered in reading a CMM specification.
The question worth asking on a supplier visit
Not "do you have a CMM" but "show me the inspection room, and show me the last first article report you produced". The room answers the environment question and the report answers the capability question, and both take five minutes.
If you would like to see the inspection room, get in touch and we will arrange a visit.
Equipment specifications are from the RAVIS capability profile and Mitutoyo's published specification sheets.