Is it right and polite to ask for a free copy of a published paper? There is a published research paper I would like to read. The website it is published in, charges what I think is quite a lot of money, considering that I won't use this for research or work.

I want to read this paper because its about a subject I am really interested in, but has nothing to do with what I study. I am a software engineering student and had never participated on any kind of research and I do not quite understand how all this things work.

So, the question is: is it right to ask for a copy of this paper to its author? If it is, how should I do it?
I don't think that it could be a problem to ask politely for a copy of this paper. It is understood, however, that you are polite and say thank you.

So, if you are interested, you should show it that way. It doesn't hurt to ask.