Roller Coaster
Roller Coaster | |||||||
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Type | Engineering | ||||||
Category | Build | ||||||
Description | Prior to the competition, teams design, build, and test a Roller Coaster track to guide a ball/sphere that uses gravitational potential energy as its sole means of propulsion to travel as close as possible to a Target Time. | ||||||
Event Information | |||||||
Participants | 2 | ||||||
Approx. Time | 12 minutes | ||||||
Impound | Yes | ||||||
Rotates | Yes | ||||||
Eye Protection | B | ||||||
First Appearance | 2018 | ||||||
Latest Appearance | 2024 | ||||||
Forum Threads | |||||||
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Official Resources | |||||||
Website | www | ||||||
Division B Results | |||||||
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Roller Coaster is a Division B event for the 2024 season, which replaced Mission Possible. It was created in Virginia in 2012 and went on to be 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 between 30 and 60 seconds.
Construction
Device
The roller coaster must be within these dimensions: 30 cm width × 80 cm length × 50 cm height. The track can be made of anything except for commercially sold tracks such as Hot Wheels, cannot have added energy by use of stored potential energy (e.g., no springs, rubber bands, magnets, or elevators), and magnets/electrical/electronic devices may not be used for any part of the Roller Coaster.
There must be exactly one clearly labeled Start Line and one clearly labeled Finish Line running perpendicular to the direction of ball/sphere travel on the track designated before the Target Time is released, and a mechanism that will safely stop the ball from moving after it reaches the finish line.
Gaps
The track can have 2 gaps, in which they can get gap scores to contribute to the total score. 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.
Loops
The roller coaster may contain only one loop to get a loop score. The vehicle must remain in contact with the track at all times for the loop to qualify for a loop score. The upper half of the loop may not be enclosed.
Ball/Sphere
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. The vehicle, if not passing through a gap, must be traveling on the track at all times (e.g, it can't bounce off of the track).
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 30 and 60 seconds (2023), in varying intervals (5s for regional, 2s for state, and 1s intervals for national) 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 must adjust their devices to the target time during their 8 minute testing period.
Examples
Note: this roller coaster is based off the 18-19 season rules, which are different from the 22-23 season rules.
In the above picture, only two gaps were constructed. Commonly, a "regain" will be built after each jump. After having one large jump, another ramp with a not as steep incline would be built, conserving all the energy which would otherwise be wasted after each jump. As of the 2019 season, a large majority of teams used a "C" or "U" jump as the 2nd, or even 3rd jump. The ball would land at the bottom of the C, indicated by the pencil lines drawn on the wooden board. It would then loop around and shoot out, out of the top of the C, allowing the ball's energy to be almost fully conserved. This allowed teams to get upwards of 80 centimeters of gap. The roller coaster pictured above had a total of 86 centimeters of gap.
Commonly, 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.
However, many teams also use 3D printed gaps, or commonly even metal or aluminium gaps. With a material like aluminium, the lack of friction allows the ball to jump even further.
The use of oil, even the tiny bit of sweat on your hands, would easily affect the amount of gap that the ball gets. By using gloves or wearing a protective cover around your hands, as well as making sure the ball is free of any foreign substances, is recommended to allow consistency in gaps.
In addition, different densities and sizes of the ball can also change the amount of gap you may get. In the device pictured, a PTFE ball, with a diameter of 1/2" was used. However, metal balls are also used for consistency. Furthermore, a regular marble is the most common, as they are the most accessible to most teams. 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. The way the current rules are written, more points can be gained through the gap bonus than through any other method, making gaps extremely important. Teams with construction or competition violations, or teams who missed impound, are ranked in lower tiers (specified by the rules). Failed runs will receive a score of zero, but will be ranked above teams with violations.
Run Score = Height Score + Time Score + Gap Score + Loop Score
Height Score = 2 x (60 - Roller Coaster height). The Roller Coaster height is measured in whole cm from the highest part of the Roller Coaster to the floor or the table (if used), rounded down.
Time Score = Time Bonus - Time Penalty
- Time Bonus = 5 points for every full second of Run Time up to the Target Time.
- Time Penalty = 5 points for every full second of Run Time past the Target Time up to the 2 x the Target Time.
Gap Score = 4 points for each whole cm measured horizontally from the end of the track the ball/sphere leaves, to the closest part of the track the ball/sphere lands on. Points are only awarded if the ball/sphere successfully reaches the track on the other side of the Gap and fulfills all requirements regarding gaps.
Loop Score = 6 points for each whole cm of the height of the Loop, measured vertically from the POI to the highest inner point of the Loop. Points are only awarded if the ball/sphere successfully completes the Loop and fulfills all requirements regarding loops.
Helpful Links
- 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
Nationals Scores
Place | School | Total Score | Time | Gap (cm) | Height | Target Time |
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1st | Community Middle School | 665 | 47 | 86 | 60 | 47 |
2nd | Tower Heights Middle School | 653 | 49 | 84 | 60 | 47 |
3rd | Kennedy Middle School | 645 | 47 | 82 | 60 | 47 |
4th | Kraemer Middle School | 608 | 64 | 78 | 60 | 47 |
5th | Harlan Rowe Middle School | 595 | 47 | 72 | 60 | 47 |
6th | Slauson Middle School | 559 | 48 | 65 | 60 | 47 |
Place | School | Score | Gap |
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1st | Bedford Middle School | 618 | 107 |
2nd | Meads Mill Middle School | 581 | 100 |
3rd | Tower Heights Middle School | 562 | 92 |
4th | Slauson Middle School | 518 | 91 |
5th | Solon Middle School | 506 | 92 |
6th | Springhouse Middle School | 499 | 92 |
7th | Paul J. Gelinas Junior High School | 471 | 87 |
8th | Community Middle School | 461 | 77 |
9th | Kennedy Middle School | 446 | 71 |
10th | Jeffrey Trail Middle School | 432 | 69 |
Division B: Science Bowl · Sumo Bots · Roller Coaster · GPS | Division C: Science Bowl · Game On · Endangered, Exotic, and Extinct · Hydrogeology |
Division B: Roller Coaster · Rotor Egg Drop | Division C: Indoor Bottle Rocket · Electric Wright Stuff |