Introduction: Paper Roller Coasters :)

About: I'm a middle school science teacher going on 20 years in the classroom. I've taught 6th, 7th, and 8th graders. I'm constantly looking to improve my instruction and Instructables is one of the places I search…
As a science teacher, this is the best project I do all year.  I have yet to come across a project where students are more engaged.  They want to come after school to work on it, they ask to take the project home to work over the weekend, students are shocked when the class period has come to an end, and they all want to skip their next class to continue working.

The purpose of this project is to reinforce Newton's Laws of Motion through roller coaster physics.  The objective is to have a marble take the GREATEST amount of time to get from the top of the first hill to where the coaster ends. 

This instructable has also been submitted into the paper contest.  I know the competition is fierce so please vote for me!

Students will demonstrate ability to:

Plan and Create a paper roller coaster 
Evaluate and test and retest their roller coaster
Analyze how to best manipulate the forces of friction and gravity
Explain the difference between potential energy and kinetic energy
Calculate problems involving free fall
Create tracks to better understand centripetal force

This assignment can be easily differentiated... make the goal time longer, make the base smaller, limit the amount of paper or tape...

Below is a roller coaster I created as an example for my students.  The video starts with an explanation followed by a test run (around the 1:50 mark).  I tried to incorporate as many features as possible onto one sheet of card stock.  The last step has a video of a paper roller coaster I created a few years ago that includes an elevator.

Step 1: Materials, Helpful Hints and Rubric

Here's what you're gonna need!

Card Stock Paper (110 # is best)
A paper cutter
Masking tape or Duct tape (you don't need the tape, just the shape of the roll for your loops and corkscrews).

Helpful Hints in no particular order.

Build from the bottom up.
Crease ALL folds.
Make a plan, but be flexible if things aren't working out.
Make good supports.
Keep the decline of your tracks to a minimum (so the marble doesn't roll too fast) unless you are trying to get over a loop or complete a jump.


Paper Roller Coasters
Objective: Work in groups of 2 or 3 utilizing your knowledge of Newton’s 3 Laws of Motion to create a paper roller coaster that can carry a marble for the longest period of time without stopping.

1. The model should be designed for a glass marble. When released from the top of the first hill, the marble will travel through the entire ride and arrive at the bottom loading platform. (For this project, the marble will be raised by hand to the top of the first hill to start the “ride”.)
2. Your team may use more than one marble.
3. Magnets, electricity, springs, and other forms of energy may not be used ­ this is a “gravity ride” only.
4. No one is permitted to touch the coaster once the ride begins.
5. There needs to be a clear “end” to your ride.
6. You will have only three chances. Your longest time will be the one you get graded on.

Step 2: Supports

Supports truly are one of the most important parts of the paper roller coaster.  All folds NEED to be creased.  The supports are the skeleton of your roller coaster and we don't want them bending or sagging.  The difference between a good coaster and a not so good coaster is the supports.

Watch the VIDEO to see how to build them or print out the PDF called "Coaster Element Instructions" in the first step.   

Step 3: Tracks

There are a few ways to create tracks.  There is no wrong way to do this as long as the marble doesn't get stuck.  It's a good idea to experiment a few different types because you may use more than one kind on the same roller coaster.  There are also a number different methods for creating turns in your tracks.  Either check out the PDF from step one or check out VIDEO 1 here and VIDEO 2 here.  You can also watch the video of my completed coaster to see a few different ways to make tracks.

Step 4: Loops and Corkscrews

Start out by making two straight tracks with good creases.  

Tape the two tracks together at the ends with about 2 cm overlap.

Cut both walls, down the entire length of the combined tracks, from the top of the wall to the CREASE.  Each cut should be about 1 cm apart.  If you don't cut all the way to the crease, it will not work.

Wrap the tracks around a roll of masking tape to get the desired shape.  

Watch the video for the rest.

The following passage comes from Kids Britannica.  The site has a terrific history of Roller Coasters.

"The end of the 19th century, the roller coaster industry was turned upside down. Literally. Flip-Flap Somersaulting loop track rides were first attempted in Paris in the middle of the century. The rides were based on a popular child's toy that exploited centrifugal force to keep a small ball rolling on a looped track without falling off. But passengers found the inversions uncomfortable and dangerous, and looping coasters were not seen again until 1895, when Lina Beecher installed the Flip-Flap Railway at Paul Boyton's Sea Lion Park in Coney Island. Though uncomfortable and dangerous still, the 25-foot circular loop proved popular, whipping the passengers (especially their necks) into a frenzy, before closing after only a few years.

Loop-the-LoopIn an attempt to reduce the high g-forces of the vertical loop, Edward Prescott Coney Island aerial built the 1901 Loop-the-Loop at Coney Island, with a softer, oval-shaped design. It was better crafted than Flip-Flap, but it would still be another 75 years before a successful vertical loop was realized. Although hampered by a low seating capacity that eventually ran it aground, Loop-the-Loop was the hot ticket for coaster enthusiasts for the next six years, until the advent of the first high-speed coaster, Drop-the-Dip (later called Rough Riders). These increased levels of danger brought improvements in safety, such as the introduction of lap bars, which kept passengers from becoming projectiles."

Step 5: Time Wasters: Toilet Bowl and Funnel / Half Pipe Hybrid

To create a funnel or "toilet bowl" you want to start with a full sheet of card stock.  
First: Draw the largest circle possible on the sheet.  
Second: Cut out the circle.  
Third: Decide where the center of the paper circle is located and cut a straight line from the edge of the circle to the point in the middle.
Fourth: Cut a hole just larger than the marble, around the point you located in the middle.  
Finally: Overlap the edges of the straight cut to create the funnel and tape into place.  The distance you overlap the edges will determine the steepness in the sides of your funnel.  

It is important that your funnel be very stable.  If your funnel wobbles, the marble will head straight down the hole and you won't end up with an effective time waster.

There are a few other ways to create time wasters.  Watch the video below for a few suggestions with instructions.  Just be creative!

To create the Funnel / Half Pipe Hybrid, you need to start with a full sheet of card stock.
First: Cut a straight line from the one corner towards the opposite corner, but only make the cut a few inches deep.
Second: Cut a hole just larger than the marble at the end of the straight cut. 
Third: Overlap the edges of the straight cut.
Finally: Tape the overlapped edges in place.

Step 6: Half Pipe

A half pipe build is a multi-step process.  No matter what, the half pipe needs to be secure.  The video can show the procedure more clearly than I can describe.  

Step 7: Paper Elevator and Use of Multiple Marbles.

It took me a few hours to get the elevator to work.  It was a very frustrating process, but it was pretty cool to see it work.  There is no optical illusion.  The video below starts with a steep drop, goes through a double loop, and straight into an elevator car.  The elevator car has a catch and release mechanism.  The elevator car is released when the momentum of the marble is transferred to the back of the car.  The elevator uses a counter weight on the far side of the elevator shaft (not visible in video) to carry the original marble back up.  The marble races though corkscrews, around turns, and over a bump on it's way to the finish.  Although this coaster doesn't take long to finish, it has features that are pretty cool considering it's all paper, tape, marbles, and a little string.  (the counterweight on the other side was made up of 4 marbles taped together).  I tried to make it work without the string, but the tape created too much friction.  I don't have step by step instructions on how to build an elevator.  I'm sure there are a number of different ways it can be accomplished.  The experimentation process is where most of the learning takes place!

An easier way to extend the duration of the paper coaster is to incorporate multiple marbles.  According to my rubric, once the first marble is released, the team may not touch the coaster.  In order to have a second marble travel the length of the coaster without student intervention, they must create a release system.  When the first marble finishes its run, it crashes into something... that pulls on a string... that releases another marble at the top of the coaster.  The second marble can either run down the same tracks as the first or you could have a completely separate set of tracks.  

I hope you have a chance to build one of your own.  If you do, be sure to send me some pictures and add any advice you have to the comments.  Thanks for looking!
Papercraft Contest

Runner Up in the
Papercraft Contest