Bad Piggies Tusk ‘Til Dawn Level 5-6 can be 3-starred using a two contraptions. To avoid a Krak-Snap, use 3 boxes and all four wheels. Place the firework on the right side of the boxes, facing left. Slowly work your way down the level, then use the firework to propel the cart over the gap and safely to the goal. To reach the star box, replace the middle box with the firework to minimize weight, then repeat the process.
If you have a different strategy for completing this level feel free to leave a comment below.