Inventor^® Training

Turn Off Inventor Automatic Constraints - Page 2

By David Melvin, PE, TEDCF Publishing

One reason you may want to do this is to manually constrain the sketch after you’ve drawn the lines. While this gives you more control over the constraints and where they’re located, there are faster ways of controlling constraints and there location. For example you can scrub the geometry you want constrained.

This example shows the bottom line being scrubbed while drawing the top line. The pointer is being passed along the line without clicking the mouse.

Doing this replaces the Perpendicular constraint with the Parallel constraint. Since the bottom line was scrubbed the top line will be constrained relative to it.

As I said above, even though inferred constraints are shown they will not be added to the lines because Constraint Persistence is turned off.

Turn it on and I’ll show you faster and more useful way to turn it off.

Click the down arrow on the Constrain panel and then click Constraint Persistence.

While you’re drawing sketch geometry you can remove Constraint Persistence by holding the Control button down when you click points. This is faster and more useful because you can automatically add the constraints you want to add, and when you don’t want to add a constraint all you have to do is hold the Control key down while you click the point.

There are no visual cues that indicate whether or not Constraint Persistence is on or off. So I recommend that you leave it on, and for those rare instances when you don’t want to add the constraint use the Control key.

Why is this important? All your sketches should be fully constrained. This gives you control over the geometry. Having more control over constraints helps you meet this goal.