First of all, everything on this site is for information only. In no way does the author make any claims as to the safety, reliability or engineering of any of the items on this site. It is the responsibility of anyone attempting the project to ensure the safe construction and operation of the attraction.
Safety needs to be the primary concern of this project. There are moving parts, and some of these are quite large. Guests will be traveling through this moving tunnel. Every effort needs to be made to ensure the safety of the guest.
This version of a spinning tunnel consists of several elements:
The framework is the base of the structure. It was made from Unistrut brand metal framing channel. Go to www.unistrut.com for more details. This is an industrial channel that is great for making all kinds of things. The framework holds six BMX style bicycle wheels (minus the tire) that the tunnel rests on. One of the wheels is connected to a gearmotor via a belt and pulley.
This is the main element. The tunnel is constructed of three rings that are connected by four rods, creating a cylinder. Think of a coffee can resting on its side. The each of the rings rests in two of the BMX wheels. Because there is no direct connection between the tunnel and the motor, if anyone were to fall into the tunnel, it would simply stop spinning. You can actually stop the tunnel with your hand. This will become clearer later. The framework of the tunnel is covered with flameproofed fabric and painted with UV paints.
The bridge is the hardest thing to engineer. Because it must span the entire tunnel, it must be beefy. You can't run a brace from the middle or it would intercept the tunnel. The bridge is constructed of two platforms on either side of the tunnel, two I-beams stretched between the platforms, and a plywood walkway. In addition, hand rails are necessary. UV lights are placed along the side of the bridge to illuminate the tunnel.
That's it! Now, on the the actual construction