Constrain movement between two values

[shelmsGYSXD]

I have a family I've created where I need the screw to be adjustable. It needs to move up and down. But only between 0'-0" and 1'-8". I want to make it so if a user tried to go outside these ranges Revit ignores it or gives an error message. Right now I am able to adjust the family but I can input whatever value I want, which I don't want to be able to do. I am new to making families that are adjustable and don't completely understand formulas yet. Can someone help?

[barthbradley · Accepted solution]

Post your family and I'll show you how to do this.  

[shelmsGYSXD]

Here is the file

[mhiserZFHXS · Accepted solution]

You need two parameters. One is the input for the user, and the other is the one that actually controls the geometry.

The one that controls the geometry needs to have an equation that says

if(input_parameter < 0, 0, if(input_parameter > 1'8, 1'8, input_parameter))

[barthbradley]

Does the screenshots I added above help you get to where you want to go?  

Here's a good resource about formulas  to read:

https://www.revitforum.org/node/1126

[shelmsGYSXD]

Yes, thank you!

[shelmsGYSXD]

Thank you!