Joint limits and drives
A movable joint — a hinge, a slider, a cylindrical, planar or ball joint, a pin in a slot — leaves the part some freedom. You can set it to a number (a drive) or bound it (limits).
Where it is set
Click the joint — its glyph in the view or its row in the Joints list. The fields of its degrees of freedom stand in the properties on the right and in the popup at the glyph; they are the same fields.
Drive: put the part in a position
- The field of a degree — an angle or an offset — shows where the part is now. Type a number or drag the value: the degree becomes a drive, the part moves to that position and stays there. The lock beside the field closes.
- The field takes a formula over the document's parameters:
pa,pa/2,90-pa. Tie several drives to one parameter, and the whole mechanism goes through its travel when you change one number in the Parameters window. - To release the degree, press the lock: the part is free again, and you can lead it with the mouse.
Limits: bound the travel
- Open Limits. For each free degree tick min and/or max and set the value.
- The part does not go past a limit, neither when you lead it nor on a recompute. At the limit the degree reads at the stop — that is the bound you set, not a fault.
- A lid that opens to 200° in the model will hit the housing in real life: a limit of 110° shows that at once.
If it did not work
- The part does not move when you lead it — the degree has a drive. Press the lock to release it.
- A red line under the joint says the mate is not satisfied — two joints ask different things of the part. Remove one of them or release a drive.