I'm getting a strange sense of deja-vu here! This thread is nearly word for word identical to
this thread!
Even the modifications to the library part are the same!
Markus, the curtainwall tool is actually made of a series of individual library part components, the overall dimensions of each being controlled by the settings within the curtainwall tool.
The frame object Laura and I both posted can be used for any of the frames in the curtain wall in AC12 & 13 once it is loaded into your library. To do this, place the gsm file into the folder where you keep your custom library parts, then in ArchiCAD open the Library Manager, check this folder is already loaded, and press reload.
Now go to the curtain wall settings. Please refer to the attached image.
1. In the Frames section select 'Boundary'.
2. Select the frame selection button above the parameters, and you will see the object you just loaded listed in the available frames.
3. Select this object.
4. Under the '3D Representation' section of the parameters you will find a new Cap Material option that allows you to choose the cap material separately from the main frame material.
5. Once you are happy with the settings of this frame you can optionally click the 'Unform Frame Classes' button at the top to make the boundary, mullion, and transom frames identical to one you have just set up.
Make any other changes you need to the general settings, then press OK. Draw the curtain wall on plan, and have a look in 3d to see what it looks like!
I hope the process is clearer for you now. Good luck!