i am a 13 year old in New Zealand and i came across a video of someone who made there own roller coaster so i decided to make my own.
the track is 30 cm and 45 cm wide with 2 or 3 15 cm planks side by side
its 65 cm tall at the start and has already been extended to 18 meters and still has about 10 meters to go.
it goes over 10 kph at some points and will end up going up to twice this speed when complete.
it is still a work in progress and has had about 2-3 weeks of work on it
hope you like it
total cost FREE all wood and side rails came from under our house
CHECK OUT THE UPDATE Backyard Roller coaster 2
YES IT IS A ROLLER COASTER AS IT ROLL'S AND COASTS
and its better than some people who make these like a skateboard on a drive way