Many thanks for this.
After several hours of trial and (much) error, I think I may have cracked it. I am attaching an updated version.
What I was trying to do was to create a generic three sash window whose component parts would remain a consistent size whatever the height and width chosen - in other words, a parametric window. I think I have succeeded but maybe not in the most elegant way.
I agree that I should have modelled it with the main axes being X and Z. I would be tempted to rotate the window but don’t dare in case that throws everything out again. Would it be safe to do so?
My guess is that DCs are an evolving part of SU and that in future it may become easier to construct them. One thing that would be nice would be to have a button in each value box allowing you to delete the contents without a process of double clicking and deleting. Also, navigation is a bit of an issue if there are a lot of sub-components (what about a fixed division below the main element so that only sub components scroll?). Another idea would be to have a shortcut so that, once you have constructed all the subcomponents, you can tell SU that you want to maintain their relative positions within the component, rather than having laboriously to set each positional parameter (but still keeping each parameter editable for special cases).
If you spot any glaring errors or improvements that could be made to my model, I would welcome your advice.
DC casement window H bar 3 light.skp (486 KB)