Linear frustration

[revitworkbench]

Hello, I am trying to get a linear family to flex incrementally to certain distances. I have written the equations and everything seems to flex fine in the family. But as soon as I load it into the project, It completely ignores my equation driven parameter? I have a feeling that it has something to do with the way a linear family is set up since I cannot delete the length parameter. Its really strange and illogical how it is behaving. I have attached the family. Please help!

[CoreyDaun]

I opened your Family, and in the Family Editor, you say that is works correctly? The length of the Extrusion seems to be directly based on the "Length" Parameter, but the formula is based on the "Length Input" Parameter. Can you explain how this Family is supposed the function if I were to input, say 33' into the "Length" Parameter?

[Alfredo_Medina]

A family that "works" in the family editor but "doesn't work" in the project environment is a family that doesn't work anyway. Long- winded formulas and unnecessary relations between parameters affect the family, too. That was part of the advice given in this thread, so that issue was addressed, too, even though you say it was not addressed. You want to make your family your way, only, so I don't see much sense in continuing this discussion.

[revitworkbench]

Yes, any value greater than 10' should return 10'.

[CoreyDaun · Accepted solution]

The Family is working "properly" in the Project Environment according to the Family. When you draw a linear Family in the Project, that determines the value of the "Length" Parameter in the Family. Since your Extrusion is constrained to the "Length" Parameter in the Family, your formula is being bypassed. You will need to create and additional set of vertical Reference Planes (left and right sides) that will be constrained by the "LengthCalc" Parameter, and then adjust the Extrusion and the Array to be constrained to those Reference Planes instead.

You will need to adjust your "Number of Holes" formula to reference "LengthCalc" instead of "Length". Also, your "Length Input" parameter currently holds no power - set the formula to "=Length" or substitute "Length" for "Length Input" in your primary formula and then remove "Length Input".

[SteveKStafford]

The attached family is a Generic Model Line Based example that will allow the user to place two points but the length is constrained to be no more than 10 feet long. If you apply the same technique in your family it should work.

[revitworkbench]

Thanks CADastrophe, stellar as always!