Here is a site that I can recommend highly as many fine videos from a person that knows coffee;
Moka Pot
Roasting
Roaster puzzle
listing Google search and go to Kave.....
Many English language videos here!
If you are not a member of Vimeo, you can sign out when the videos are poor and reload to get to see many more.
~Richard/ Espressme
PS ere is his Home Page for a lot of wild ideas and products!