Abstract: A nutcracker having a reciprocating hammer whose movement follows a rotating cam. An adjustable cracking space dimension is determined by the adjustment of an anvil. When the cam rotates so that the low dwell region is in contact with a cam follower of the hammer, the hammer withdraws from a cracking space between the hammer and anvil; during this period, nuts/seeds fall from a hopper into the cracking space. As the cam rotates to the high dwell region, the hammer oscillates into the cracking space which then forces the nuts/seeds against the anvil and cracks them. As the cam continues to rotate again to the low dwell region, the cracked nuts/seeds and shells are dispensed from the cracking space and more nuts/seeds fall into the cracking space from a hopper. The cams are replaceable to accommodate different sizes of nuts, different cracking times, etc. The anvil can also be adjusted to change the width of the cracking space.