security handle for velux windows free 3d print model 無料 3Dプリントモデル

This is a very very interesting piece of work has Velux has stopped manufacturing the parts for their older Velux windows.

I am prepared to print it (got a quote of 109 euros at a local 3D print shop) ...but there is one thing I actually don't understand: how are the two parts security connected one to the other. When looking at the design, I have the feeling that one has to "clip" the part in the other one.

This raises two questions:
1/ is it required that the print material would be flexible enough in order to be able to click the two parts together?
2/ if it can be clipped "in", is it really a "security" handle? Isn't there a risk that it would be possible to force the window and "unclick it"?

Let's see if I get some answers to those two questions.

Imho, a better design would have been to make the two parts easy to connect at another angle (e.g. rotating further to the right) but to have a non cynlindric design for the interconnection, by example with a narrower parts that would prevent to "unplug" the parts.