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Hi All,

I am want to make dynamo script for duct hanger. Everything is done but last three node values are showing NULL value. Does anyone know how I fix this issue?

Can you take a picture of the graph instead of just a piece of it? :slight_smile:

I have attached the dynamo script.

Duct Hanger.dyn (105.2 KB)

Have you created the parameters “Support height” and “Fixing height” in your Revit-project?


Ah, they are type parameters.

Then you need to use Element.ElementType before assigning the value to the parameter.

Hi Vestesen,

Still same massage coming.

Hi Vestesen,

I have attached hanger family also. Could you please check once.

Thanks,Dyanmo Trapeze Hanger.rfa (368 KB)

The problem is that you’re trying to place a non-linebased family with alongside a line.

You have two options.

  1. Create a new family which is line based.

  2. Get centerpoint of the line and place the family that way. In this case, you need to make sure the angle of the family is correct.

Example. Didn’t checked angle in this one but the hangers are placed.

Did you update the family?

Nope, did nothing with the family :).

Instead of Metric Generic Model you should use Metric Generic Model Line-based

Hello Vestesen,

Now perfectly working. Thank you so much…


As per my script one size duct support placing everywhere (like attached snap). How I control hanger length according to the duct width. Please give me suggestion.

Retrieve the diameter from the duct with Element.GetParameterValueByName and then add it to the hanger.

Another issue is Duct support levels are not taking the information from the List.Flatten node.
Please see the attached snap for your understanding.


How I fix this one?

I see that you have a few threads relating to different parts of this graph.

If possible, can you provide a full screenshot? It would be a great help.
If I understand your graph correctly, the Fixture Height parameter sets the Trapeze Height and is supposed to be flush with the bottom of duct?

If so, you need to resolve your raybounce issue to have the correct output list.

Duct Hanger_1.dyn (106.6 KB)

If possible could you please update the script?