Hey guys I was wondering what the best machine, premade or fabricated by a friend you have come across that is the most efficient in creating keif from your trim?

One of my buddies had a decent amount and was wondering the best way to go about it. He had an idea to have three trays with gradually smaller screen sizes much like the bubble box idea, but a lot bigger and that vibrated/shook on its own. I don't know how feasible it would be, but it just seems like these tumblers cost way too much.

Thanks