I have DC (as attached)spf_310_A.skp (42.2 KB)
I would like to change dimension (leny and lenz) using:
set_attribute(“dynamic_attributes”, “leny”, 90)
I use set_attribute to instance, I use set_attribute to definition. I use recalc_dc (Dan’s method) and nothing…
DC dosn’t want to change their dimensions!!!
Some hint, please 
_LenY dosn’t work 
You should download the Attribute Inspector to see how it works. Most of it says your leny attribute is defined for definition.
Also, you should make SketchUp redraw the model after the modification, else it won’t show…