Marbleworks Compatible Twist-tie

This is a part of a parent collection of many different marble tracks compatible with Marbleworks Grand Prix marble set. See remix source for larger collection of marble tracks.

This design provides some twisty adventures where the parts may collide at the risky center junction! The twist-tie has marbles approaching from opposite directions, though you shouldn't have any world smashing events as the walls cover their escape paths fairly well.

For those of you who want to know the math involved, the paths are defined by:

```
x(t) = sin(2 t)
y(t) = sin(t) cos(7 t)
```