Change Arrowhead parameter for all family types of a family

@john_pierson was very kind to start guiding me in this endeavor in a previous thread and think it’s best I start a new thread as that one was already solved.
I’m trying to change all the arrowhead parameter of all the types of a specific generic annotation family without having to go one by one for each type.
After a quick tutorial, I started experimenting with the Revit nodes in the latest version of Dynamo. I got this far:

It was suggested that I use “Arrowhead Assigner” and would like to know how to incorportate it or if I’m even going down the right path.

Thank you, everyone!

The arrowhead parameter requires a element instead of a string so you have to get the arrowhead element and plug that into the value.

Hi @cescobar

And also Remember your setting the family type so you should do this changes before you assign arrowhead element types.

1 Like

Thanks @Brendan_Cassidy
How do I get the element of a specific arrowhead so that I can plug that in?

Thanks, @john_pierson!

I love how everyone is so helpful and responsive in this community.

It’s pretty exciting when you see it do its magic.


Awesome thing. This was actually the first thing I did when I learned Dynamo. Ah, the memories!

Great work!

1 Like

@cescobar Could you please mark @john_pierson reply as solution. Thanks!

Here is how to mark.


Thank you as well @Kulkul.

I have a dead-line and was wondering if someone would be so link as to upload this DYN.

Change Arrowheads in Family Types - Keynote-Blocknote Tag - RM.dyn (7.5 KB)
You’ll have to tinker with it a little. Hope this helps.

John’s nodes and the Rhythm Arrowhead Assigner both work great (thanks to both), EXCEPT …

…after a lot of poking into this and searching, I still can’t find any way to set leader arrowheads to “None”.
I can’t find an ElementType for None to use in John’s nodes, and the Rhythm Arrowhead Assigner fails with “None” as an input.

Any solution for None would be wonderful.

  • Rusty

Hi, This is a great start.
I changed great number of mine to be consistant however after 200ish changed, it starts to erase associated note blocks. Literally, deletes the family.

Would you know what is causing this? I am thinking element ownership or there’s a threshold on the number of items you can change?

Would anyone know?

I haven’t experienced this or maybe didn’t notice. Do you mean that it deleted some elements (instances of the family) or the entire family from the model?

It deletes entire family from the model.

So, if I had the note block on the legend and also a user referenced on multiple views, they are all gone. I think it is the dynamo language issue or there is a flaw in the algorythm.

If you are having a issue that is away from the original post you should start up a new topic.

Setting a parameter that accepts elements can be set to null via some python code and utilizing “InvalidElementId” which can be found within the SDK for revit.