Qualification type confusion

[[Jo...]]

Hey guys,

In my recent Calypso Advanced course we worked on automatic probe qualification programs, and the recommended type was Geometric Qualification. We’ve always used tensor at work.

From the user guide it sounds like tensor focuses more on the flex of the stylus and geometric qualifies the xyz and radius.

Can anyone shed more light on this for me? Should my qualification program include both geometric and tensor?

[[Ri...]]

On an Active Sensor, Tensor is calculating the bending parameters, XYZ location, and the form of the stylus.

Geometry Requalification is only calculating the XYZ location, and the form of the stylus.

You will see differences in the two qualifications on an Active Sensor because the Geometry Requalification is using less amount of points to calculate the deviations. (Typically the Geometry Requalification will show better).

On a Passive Sensor, Passive Qualification is calculating the bending parameters, the XYZ location, and the form of the stylus, BUT it calculates the XYZ location, and the form of the stylus using a Geometry Requalification style qualification of either 5/6 points around the equator. The "death spirals" are used for the bending parameters.

You "shouldn't" see a difference between a Passive Qualification and a Geometry Requalification on a Passive Sensor.

[[Jo...]]

Sweet, thanks for the info.

So I should be fine with running tensor only during my automatic qualification?

[[Je...]]

On our DuraMax I have "huge" differences between "passive sensor" and "Geometry Requalification".

Espacially with star probes. I´ve had deviances from left to right about 0,01mm. With passive sensor I´m in an expected area of less then 0,005.

[[Je...]]

Tensor or Passive Qualification are only needed if a physical characteristic of the stylus changes. IE - twisted, tip swapped, config modified etc.

If no changes have been made, a "Geometry Requalification" is sufficient. A full Tensor or Passive (sensor dependent) is still OK to do but not needed on a frequent cadence.
My personal recommendation;
If a full production machine running 24/7 - once per week at designated times.
If full production but intermittent/shift shut downs - bi-weekly on start of week/shift.
If non-production/prototyping/job-shop - 1st of month is more than sufficient.
Any, if crashed or altered in any way - immediately

The only reason for this is that it is more likely to catch a physical break/chip/crack in the stylus tip or shaft itself as there is a more robust scan. These events are rare unless a crash occurs. If a crash occurs, I recommend full requalification of the suspect probe configuration.

[[Ri...]]

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Yes. That's why I put quotation marks around shouldn't. Lol.

I used to manage a lot of CMMs, and a lot of them were a DuraMax. I've seen Geometry Requalification give horrible qualification results that could only be resolved with running a Passive Qualification. I never studied it enough to understand why though. Could be a temperature issue, or something else.

I will say though, that is most cases the Geometry Requalification is sufficient enough, but as with any qualification, you should always check the results.