Yeah, I was puzzled about why modo_mario thought you might need a machine shop to make a hay rake — sounds like the kind of thing Primitive Life might make with stone tools. So I checked out the John Deere model number mentioned in the spreadsheet, and it turns out that the hay rake in question can rake hay at utterly inhuman speeds over a wide swath of your field. Handy if your cows are depending on you for winter fodder.