I made a fully automated scrapbox factory with the help of Buildcraft. Without Buildcraft you would need to manually feed the cobble into recyclers and craft the boxes yourself, still quite cool, if you only need to feed 5 EU/s in and get tons of scrap out.
The automated cobble factory is inspired by this wiki article.
The whole thing is shut down if the ore block is accidently mined, this will prevent the ore block from being processed to scrap, also it will turn on a warning light so you know you need to replace the ore block. The miner can use normal pipes or diamond pipes, the latter will produce cobble faster than Buildcraft can transport, so the chest will fill up slowly. The power to the miner is switched off, if the ore block is mined, while this won't stop the miner alone it can't go deeper, because there is water under the maximum depth of the mining pipes.
I already managed to build a generator that can detect if there is a cobble block or not, but I didn't manage to shut down the miner in time if there is none, so sometimes after you load the map it will mine the ore block and stop after that. Only thing to do is to replace the ore block again and it will start. Also the clock I am using for compactness won't survive a map load, most likely.