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Implementation of DIN5459 for datum system creation in general with Quindos and its validation in measurement comparison to Zeiss Calypso software

Hello Quindos World,

as I have not found any Quindos user with larger experience on that topic yet, I am very interested in experiences and opinions on this topic.

We are working in automotive industry and have a larger group of customers using Zeiss Calypso software. Many of them using the inbuilt function "Datum creation according to DIN5459, with tangential elements"

As far as I understand this option creates datum systems which uses "tangential" elements for position and direction of the datum system.

At our place (at least until now) it was common to use Gauss (LSQ) elements with the "BLDCSY" command for creation of the datum system. And of the colleagues I know of at other companies I also only saw them using Gauss (LSQ) elements.

This difference in datum creation leads to measurement differences (e.g. position, coaxiality etc.) with customers on same part.

So my questions would be :

- Any of you guys had this kind of discussion internally or with customers using Calypso before and/or is regularly using datum creation according to DIN5459 where the drawing implies ?

- Any of you guys regularly using the "BuildDatumSystem" command and have any experiences how it compares to the mentioned option in Calypso ?

- I guess as it uses tangential elements scanning and filtering is a must ?

as more customers seem to use it I need to gain more knowledge on that topic and how to implement it in Quindos accordingly.

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  • The calculation type is limited to Gauss and Minimum. This will work for a scenario where a higher order precedence datum may constrain the plane.

    Will this find the three most outbound points and construct a plane from them? Please note it's not quite as simple as that as a center of gravity must be calculated to inform whether the three points selected reflect the way a real planar surface interfaces with a perfect datum simulator.

    So far, I have not seen a solution to the planar primary datum hard gage replication conundrum.

  • There are many ways to define a contacting (tangential) plane. Which definition Calypso is using we cannot say.

    Up until recently, the ISO 5459:2011 default association for a primary datum plane was [CE] = "Cheby with outside-material constraint" which is available in Quindos via MeasPla (ITY=CBYP).

    The new ISO 5459:2024 revises the default to [EM]+[GE]. We have an experimental implementation which you can access for testing via MeasPla (ITY=EGEH). A peculiar feature of the new default is that it includes a convex-hull filter [EM] in the association. If you want to test the [GE] = "Gauss with outside-material constraint" association without the filter you can use MeasPla (ITY=GSEH).

    As we only have limited experience with this new functionality, we would appreciate it if you could give us some feedback.