Tried the harvester with oreberries, it manages oreberries in a 11*11(length and breadth) are in front of its face(centered on it). i dont know the hight level.
sorry for my weak english
u can convert tin into iron if u have ic2 and tconstruct or TE4. simply craft a bucket with the tin (is possible, google it) and smelt it. Volia! u get about 482mb of molten iron. cast them into ingots.