This article was taken from the November 2014 issue of WIRED magazine. Be the first to read WIRED's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.
When his ten-year-old son asked about building a roller coaster in their garden, Will Pemble, a management consultant and founder of web-hosting company web.com, offered to help. Six months later, the result was a 55-metre track, built for around £2,000, which, according to Pemble, "has gotten a bit out of hand". Here's how you can build your own roller coaster.
For the roller coaster (makes 15 metre of track)
Tracks 6x 5m sections of 50mm O/D PVC pipe • Ties 50x 37cm four-by-twos
Stringers 12x 1.7m four-by-twos • Posts 11x 3m four-by-fours, 5x 40mm x 10mm dowels, 400x 100mm Torx head deck screws, 40x 25kg bags of concrete
Plot your course To plan the course of your roller coaster, and to calculate the height of the posts and the length of track you want to build, Pemble recommends the roller-coaster simulator NoLimits 2. "It's nearly auto-CAD for roller-coaster design," he says.
Bury your posts Dig post holes every 1.5 metres along the route. "Each should be about a third as deep as the height of the post and 25cm in diameter," says Pemble. Cut the posts to size -- remember a third will be underground -- then place in the holes and fill them with concrete.
Prepare the rails Drill two holes in both ends of every tie and use deck screws to fix them across the top of each post in a T-shape.
Drill two holes in the side of each PVC pipe -- "make sure to countersink them on the outside," Pemble says. Then screw them on at the end of each tie.
Keep on track Repeat this to join ties every 30 centimetres along the pipes. Then join each of the five-metre track sections to the next one by placing the 40mm dowels inside the ends of the PVC pipes and then drill and screw through this to attach a tie at the join.
Secure the straight runs For the straight sections of the track, attach the longer four-by-two stringers between each post, running along the centre line of the track. Use deck screws to attach the ties -- this will prevent the track flexing underneath the weight of the car as it passes.
For the car
- 12x 50mm castor assemblies and bolts to attach
- 2x lazy Susan bearings, with the ball bearings removed
- 60cm x 90cm wooden platform
- 2x 610mm four-by-twos
- 4x 270mm four-by-twos
- 4x 190mm four-by-twos
- 2x 89mm x 610mm x 12mm plywood
- 4x 89mm x 270mm x 12mm plywood
- 4x 89mm x 190mm x 12mm plywood
- 8x 130mm x 10m bolts and lock nuts
- child's car seat
Fix castors in place Bolt the castors at each end of one 610mm four-by-two, with 420mm between the centre line of each wheel. Bolt two more castors to the centre of two of the 270mm four-by-twos.
Use four deck screws to attach these at right angles to the end of the long four-by-two.
Attach the windbreaks Bolt two castors to the centre of two 190mm four-by-twos and attach the end of each at right angles to the 270mm four-by-twos. Both ends should hook around each pipe with all wheels running along it. Screw the plywood boards to the outside, then repeat for the rear.
Requisition a kid's car seat For the main car, bolt a large car seat to the wooden platform. To attach the wheel assemblies, place a lazy Susan bearing between the top of each assembly and the bottom of the cart platform and use a large bolt to join them together in the centre.
Find a crash-test dummy "It's really very important when you're doing a project like this to test it to 200 per cent of the normal load first," Pemble stresses. "I can't tell you how many bags of sand I've killed testing my roller coasters, but I can tell you that no kid has ever come to any harm."
This article was originally published by WIRED UK
