I am making a list of the things that different characters did on the track to build it. This will give names for the important track parts, and help populate the new workers pages.
The first three video snippets set the stage (literally) for building the marble track. In the first video snippet Rabby pulls the base into place.
In the second video snippet, Garinoppi flies the bearing into place
In the third video snippet, the right angle character (unnamed) helps draw a circle on the stage, and the screwdriver (unnamed) screws the bearing into place.
In the first part of the fourth video snippet, Francois drags and kicks the stage into place.
Then we finally get to some track construction
0:35 Big brother puts the central track skewers down, and the brothers arrange and place the First Track before the First Roll at 0:52
1:10 Mr Greene and Squarehead placed the Right Side Small Landing Zone
1:23 Mr Greene and Squarehead place the Left Side Small Landing Zone
1:28 Reversible Guy and Squarehead place the Lowest Largest U-turn
1:40 Reversible Guy and Candy Mama install the Lowest Back Left Small Marble Curve
1:43 Big Brother and Mr Greene set up the Lowest Largest Backtracking Chopstick
1:50 Reversible Guy and Candy Mama place the Left Side Medium Landing Zone
In the fifth video snippet:
0:02 Reversible Guy places the Lowest Largest Backtracking Popsicle Stick
0:12 Mr Greene places the Snake Plate
0:13 Mr Greene places the Below Lower Zig Zag Track
0:18 Squarehead places the Back Right Medium Landing Zone
0:19 Mr Greene and Candy Mama place the Snake Plate U-Turn
0:25 Squarehead places the pieces of Little Wiggly Track
0:30 Candy Mama places the Caret Splitter Right Track
0:31 Squarehead places the Little Wiggly Track Sidewalls
0:32 Candy Mama places the Snake Plate Chopstick
0:49 Mr Greene, Candy Mama, Squarehead, Reversible Guy place the Triple Splitter
There is a whole minute of video after that, but nothing much happens construction-wise; they were busy looking for the Little Brother while I was trying to figure out what to do next on the track.
In the sixth video snippet:
0:14 Candy Mama works on the Lowest Small-Medium Splitter, which is the last thing she does before having to take a break due to too much spin.
0:56 Squarehead and Reversible Guy install the Snake Plate U-turn Berm
1:10 Dr Sugar starts working on the Triple Splitter (3S) Small Marble Catcher
1:28 Pinky installs the Decorative Walls after the Lowesst Small-Medium Splitter
1:35 Pinky, Reversible Guy, and the Snakes install the First Snake-Installed Rail
1:40 Reversible Guy installs the Upper Splitter and Lower Curver off the Lowesst Small-Medium Splitter
1:54 Reversible Guy installs the Caret Splitter
1:57 Busy Snake and Dr Sugar finalize the spacing on the Triple Splitter
2:?? Reversible Guy places the First Placed Outer Spiral Support
So far in the seventh video snippet:
0:09 Dr Sugar and Mr Greene install the Lower Zig Zag along with the help of Autosticks
0:09 Reversible Guy installs the Second Placed Outer Spiral Support
