PVC pipe is flexible, but not too flexible. It would take a lot of force to hold it in place if we don’t form it. (It would also take permanent footings to take the load as well.) We don’t want those residual stresses in our pipe anyway as it will weaken the pipe’s ability to carry additional loads from the cart. Therefore, we are going to use hot sand to form the rail pipe over a fixture.
Getting the Support Locations for the Forming Template
Before we begin, we need a tool to make our templates. For rails with constant radius, this is based off the equation x^2 + y^2 = r^2 and from that we can plot the points where we need to support our rails. I have created this Constant Radius Rail Guide to remove the math. Fill out the form to get access to the Roller Coaster Templates. Enjoy!
Creating the Fixture
Showing the Forming Process
Recommendations for the Future
- Add a continuous furring strip that the pipe will lay on. A 1.5 x 1/4″ strip should be added to the fixture to prevent divots in the pipe. These are available at your local home improvement store.
- Adding more locations to have a lead in / out transition track. Having a transition track will allow the rider to smoothly convert from a straight section of track to a curved one. (More to come on this topic in the future.)
- Do more research on how to incorporate clothoids (Euler Spiral) to ease transitions from one track element to another.
- Develop a fixture rack with adjustable set points for easier fabrication of clothoid sections
- Developing a method to analyze and form 3 dimensional pipes.
