Notice: This is an old design. An improved version can be found here: https://www.thingiverse.com/thing:4928509

I chose to make the spacing between each piece 0.3mm to increase the amount of different printers that can reliably print the model successfully. Of the pieces wobble too much you can play with the flow settings until you're happy with the result.

If the pieces it stuck together just try breaking at them until they come loose.

I recommend lubing the puzzle after printing to increase the smoothness of the motion.

If possible: Change the filament color for the upper three layers.