This machine requires an active Climate Control Centre in order to work.
Standing on a completed Hard Rock Grinder will kill you, so beware. Doing so will give you the "No... the OTHER Grinder." achievement.
Once placed on an 3x3 ore patch and provided with up to 500 PPS, the Hard Rock Grinder will begin harvesting. Unlike the Ore Extractor, this machine can't be upgraded with drill motors or cutter heads. The machine has an internal storage of 2000 ore blocks that can be collected by placing storage hoppers next to it.
As soon as all ore has been removed the machine will self destruct, leaving only a 2x3x3 area filled with Rubble.
If dug up, this machine will only return 8 of the 9 blocks used to construct it.
This device can only drill downwards, it will not work if placed on the sides or on the bottom of ore veins.