Summary

Wine barrel shaped puzzle with 12 interlocking pieces. Similar to any Burr puzzle.

Instructions

First print all 12 pieces. P6 will require support.
1 of p1, p2
2 of p3, p4, p5, p6 ,p7

Then enjoy assembling it.

Scad file is included in case you need to make adjustments.
Adjust variable e to be about the layer thickness of your printer to allow for tolerances and free travel. Setting to 0.1mm for my printer works great. There's also some commented out code to generate a whole barrel, and to assemble the pieces in place, with spacing for visualization - STL posted, but I haven't had any luck printing it in place -- the pieces refuse to move, even with the spacing.

Wine Barrel Puzzle