Need help with Element.SetParameterByName

hi there
I have a problem with changing the instance parameter to curtain grid family, the angel’s changes in dynamo between the normal and sunbath, but the instance parameter on Revit won’t change, I used spring element type to make the Element.SetParameterByName node work, but still the family parameter won’t change!

here it is some images shows nodes and how the normal lines and curves appear on revit, but still NCP value dose not change , thanks for your help ^^
note: i got those nodes from a website for profissor Roh

First question, why you use elementType.duplicate from Springs? You probably want to filter element types by boolmask, but not sure.

thanks for replying Tomas, I will give it a try. but i think i will get an “no function called” error

and there it is !

Your parameter name needs to match exactly: NCP not ncp.

thanks for replying @Nick_Boyts , i solved by using "spring null set parameter "