Yes, 3d printers can be useful. First time trying a puzzle-fit, and it worked great!
Files at http://www.thingiverse.com/thing:592463
Experienced all kinds of bugs: (1) an actual bug that got onto the hotbed crimp and fried it, (2) a Marlin firmware bug that prevents the filament from going forward (but still allowed retracts?), (3) filament bug: old brittle filament that broke or stripped, (4) hardware bug: worn filament gear + insufficient EZstruder tension.
