Crossover
Crossover is the point at which the gas spring takes over the lifting action (or gravity takes over to close).
This will normally be around 10° to 30° from fully closed.
In practice, this will vary by several degrees between opening and closing, due to factors such as friction of the internal components of the spring, hinges and end connectors.
Self-Rise & Self-Close
Self-rise is the angle at which the gas spring will lift the lid without any assistance from the operator. Similarly, self-close is the angle at which the lid will close without any assistance.
In most cases, it is undesirable to have the lid open without any operator input (referred to as “instant lift”). This behaviour is unpredictable to the operator and can allow the lid to open without any warning, in instances where the P1 force increases above nominal due to elevated ambient temperatures, for example.