my dear friend, i do not understand your action.
this is design forum, and we come here to communicate and learn each other. so, why do you set your drawing so expensive? which is a great barrier to communicate free.
in reality, there are many specialists share free their excellent drawings in public. it is hard to imagine that your work is more valuable than these specialists'. so, your behavior is fully ironic...
I had once worked in American-funded enterprise, and repeatedly communicated with American engineers and specialists face to face.
in addition, pls sdgdjgb, our mentor, do not interpret my english sentence with YouDao (有道) software, which translation is always with obvious error.
thanks very much!