I tried making one many years ago. Used a piece of angle iron with holes in it that dripped onto a galvanized sheetmetal that angled down about 3 ft to a bucket of cooling water. Didn't work very well cause i couldn’t keep the perforated angle iron hot enough. Also the few drops I did manage to get on the sheetmetal soldered themselves to the drop sheet. Oh well, the project kept a young poor boy entertained for a week or so.
There use to be some units out there for the home enthusiasts, but the few reports I heard about them wasn't very encouraging. That was a long time ago though. Maybe someone has come up with a better idea.
