To begin, there's a lot going on in this family, but I'm only concerned with the Hook Length here.

As you know ACI has a standard 90 degree hook length. When we place this rebar detail component, we would like to either:
  • show the Hook Length at it's actual ACI standard length (6" for a #3 bar), OR
  • allow the length to be adjustable via instance parameter (using grip to adjust length).

So, the "Hook_Length" parameter shown is an instance parameter.
I created a Yes/No parameter called "Std_Hook_Length" (instance parameter)
And then I typed the needed formula (highlighted in blue).

And of course, it returns an error: "There is a circular chain of references among the formulas, since I'm using "Hook_Length" in the formula for "Hook_Length".

But I'm not sure how to fix it. I could use 2 different families: one with a variable hook length (instance parameter), and one with a hook length TYPE parameter. But I would really like to keep it all in the family.

Is this possible?
How do I fix this?Screenshot 2024-03-04 100241.png