Don't change the wrapping direction halfway through!
Chris Fastie, April 22, 2015
A Redstone Rig under a pendulum suspension. The flying line is wrapped around the stiff wire at the top.
Most pendulum suspensions have a cross piece or stiff wire at the top for attaching the flying line. The standard way to attach the line is to wrap it several times around the cross piece which makes it quick to attach and detach. Several wraps produce enough friction to hold everything without slipping. I have been recommending that the line be wrapped so that the spiral changes direction half way across (where the top of the pendulum attaches). With the KAPtery pendulums and others of similar design, that can lead to disaster.
The correct way to wrap the line around the stiff wire -- the spiral is continuous from one end of the wire to the other. If the spiral instead changes direction, bad things can happen.
The stiff wire at the top of a KAPtery pendulum passes through a hole in the flexible tubing (and through a short fiberglass tube inside it). There is nothing to prevent the wire from turning in this hole. So it is important that turning the wire will not cause the flying line to become loose or unwrapped. But that is exactly what can happen if the line is wrapped the way I have been telling people to wrap it.
The video below shows how the stiff wire can rotate and completely unwrap the flying line with disastrous consequences. So remember to wrap the line in a continuous spiral from one end of the wire to the other.
The KAPtery's pendulum suspensions all include the materials to make a safety lanyard. This is an independent attachment between the flying line and the camera or rig. It's a really good idea to always use this lanyard.