Designer Andrew Crowell writes about his puzzle:
"Two packing puzzles in one box! These are 3D printed puzzles I designed, called ACorn 1 and ACorn 2... These are both part of a series of apparent solid packing puzzles I have named the ARCparent Cube Series. This puzzle contains both sets of pieces for ACorn 1 and ACorn 2 and the ACorn Box.
The goal is to arrange the pieces so that the box appears to be filled with an 'Apparent Solid', i.e. the box is holding a solid object without any gaps showing. The second and third photos show examples.
ACorn 1 is a bit easier than most of the others in this series. It has only a few possible assemblies which will make the box appear to have a solid object inside, i.e. no gaps showing, and only one of those can actually be solved.
ACorn 2 has quite a few more possible assemblies, again though only 1 assembly can actually be solved. It requires more moves than ACorn 1 and should provide a decent challenge. Both of these are easier than the ManiAC Shuffle puzzles.
Rotations are allowed and encouraged. The puzzles are shipped in a disassembled configuration."