Allow family to be adjusted in model with arrows

[shobaika]

Hi, I created a simple threaded rod as a generic model family in Revit. I would like to add it to model and be able to adjust the length of it depending on the situation in my design. I want to adjust it by moving an arrow up and down to increase or increase the length. How can I add the option of the arrow to adjust the length?

[ToanDN]

Create a rel plane or ref line, place a dimension from the origin ref plane to that line and assign an instance length parameter, constrain the end of the road to the line then you can stretch it in the project with a grip.

[fabiosato]

Hello,

It is also essential to check if the reference planes or lines are set to Strong Reference or Weak Reference for it to work.