Calypso 2025 (8.0) GDT characteristics vs Classic GDT characteristics

[[Ni...]]

With the recent update to Calypso, a new version of form & location characteristics are available. I am hoping to gain a basic understanding of the differences between the 'Classic' GDT characteristics vs the 'New' GDT characteristics and how they may impact measurement results when using one version vs another. My understanding is now we have 3 characteristics options for the form and location measurements..

1.      GDT Classic - characteristics calculated based on 'Calypso'
2.      GDT - ISO
3.      GDT - ASME

Is there specifically one of these types of characteristics vs the other that is 'best practice' to use? What are the major differences between the 3?

 

 

 

[[Ri...]]

Think of it this way. 

• Legacy - this is what Calypso had been using prior to 2025. Still powerful and in most cases gives you the results you are looking for, but is limited in some of the complex evaluations (mainly regarding datum shift). The Legacy requires that you setup the evaluation parameters based upon your own requirements (OTE, LSQ, etc). 
• GD&T ISO - new GD&T engine, but by default the evaluation will be according to the ISO standard. 
• GD&T ASME - new GD&T engine, but by default the evaluation will be according to the ASME standard. 

You can also switch the program from ISO to ASME and vice-versa via Characteristics Settings Editor - Characteristics (Settings of evaluation) - GD&T Standard

 

In addition, you can switch from the standard to Loose/Free inside of the characteristic. 

 

Loose will set the evaluation parameters LSQ, and also allow you to use alignments instead of building the DRF.