Joint limits and drives

A movable joint has not only freedom but also its bounds.

The same mechanism driven to 0°, 40° and 80°: the arm moves by the rule, not by hand.
The same mechanism driven to 0°, 40° and 80°: the arm moves by the rule, not by hand.

Limits

A limit restricts motion: a hinge opens to 110°, not to 360°; a slider travels from zero to its stroke. The solver honours a limit that is set — the part will not go past it, neither by dragging nor on a recompute.

Why: the assembly stops showing impossible positions. A lid that opens to 200° in the model will hit the housing in real life, and it is better to see that now.

Drives

A drive is a set value of the freedom: “this hinge is turned by 30°”. It sets the position rather than bounding it.

The value takes a formula with global parameters. Hence a simple technique: tie several drives to one variable and watch the mechanism go through its whole travel by changing a single number.

Component arrays and mirrors →