Why Ref. Level and Reference Plane overlapping

[jnoordzij]

Hi,

why is it that in families there is a Ref Level and e Reference Plane overlapping ?

To which one should i constrain when making parametrics?

[cbcarch]

Since a Family does not have "Levels", like you have in a Project, it has a "Reference Level", which will align the Family when it is placed into the Project environment, by default at the current Workplane in the Project.

When using dimensions/constraints, etc. in the family editor, you can lock them to either the Ref. Level, or to Reference Planes--some of which are "hard coded" in the Family Template, and you can also add more reference planes as needed.

So, there really is no "right or wrong" method--it just depends on what you need to achieve with the family, both inside the family editor, and inside the project.

[barthbradley]

That's up you and the Family Template you are using. Some Templates don't allow that Ref. Plane to be moved from the Ref. Level, others do. Whether it moves or not, you can align and lock elements to either one of them.  If you want those elements offset from the Ref Level, you would align and lock them to the Ref. Plane and then pull a dimension between the RP and Ref. Level, and then label it with a Parameter or give it a fixed dimension.  If those elements that are aligned and locked to the Ref Plane are to never move from the Ref Level, then lock the RP to the RL.  But, there's no best practice rule, that I'm aware of.  

[jagostinho74]

I have had problems in the past where the family would break if constrained to the Ref. Level.

As a default rule, I always TAB+Select to the overlapping Ref.Plane when setting my constraints.