Roller Coaster

Roller Coaster is a Division B event that is set to rotate in for the 2018 season, replacing Mission Possible. It was previously a trial event in many states, as well as at the 2017 National Tournament and 2015 National Tournament. The objective of the event is to design and build a roller coaster, using spherical vehicles, to travel the track as close as possible to a target time.

Base
The roller coaster must be on a flat base. The maximum dimensions of the base are 60 cm by 60 cm. The roller coaster may not extend past the base. Also, the whole device (minus the 'train') cannot exceed 80 centimeters in height.

Track
The track can be made of anything except for commercially sold tracks such as Hot Wheels. Teams must be able to lift the 'vehicle' off the tracks in a direction perpendicular to the direction it is traveling at any point. For example, a pipe would not be a viable track, as the train is not accessible from any perpendicular direction in that case. Tall walls are allowed, however, as long as they follow the rule just mentioned. The track may have an unlimited number of gaps, up to 5 of which can count toward the gap bonus. In order to qualify, the gap must have a horizontal span of 5 cm and the vehicle must be unsupported. These gaps must be labeled.

Vehicle
The vehicle can be any spherical object. Some possible items include marbles or ping-pong balls. Different objects will move along the same track at different speeds and may be otherwise affected - for example, some vehicles may require a steeper slope to begin moving.

Time Target and Other Construction Rules
The roller coaster must be designed so that the vehicles can complete the track in a variable amount of time. The target time is a specific time between 25 and 45 seconds, in varying intervals (at higher levels, the allowed intervals are smaller). The event supervisors at the tournament will choose a target time and tell it to each team as they begin their 8 minute testing period. The target time should be the same for all teams Teams will then have to adjust their devices to the target time during their 8 minute testing period.

Examples
A foam pipe insulation cut in half can be used as the track. It can then be elevated using wood dowels, attaching it to the base with hot glue, super glue, wood glue, nails, etc. In this method, a good train would be a marble or other small, round object. If the time target is not being achieved, try increasing or decreasing the weight of the train. Another method would be, similarly, PVC pipe cut in half with joints, though it would be harder to make turns.

These are not the only methods. Feel free to try things out on your own and find out what method works best for you!

Competition
The event supervisors will announce the target time to each team at the start of their 8 minute testing period. The event supervisor will also measure the team's device before testing - this does not count toward the 8 minute testing period. Each team is allowed up to two runs, which must start within their testing period.

Scoring
A team's score is determined from their single best run. A run's score is calculated based on the height of the device, the accuracy of the run (closeness to the Target Time), and the Gap Bonus. Teams with construction or competition violations, or teams who missed impound, are ranked in lower tiers (specified by the rules).

Helpful Links

 * [[Media:2016 Roller Coaster Trial Rules.pdf|Trial Event rules used for 2016 from soinc.org]]
 * A picture of a rollercoaster, found on the National SO website
 * An example score sheet, also from soinc.org