Chapter 31: Using Weldments
FIGURE 31.4The 3D planes PropertyManager
3D planes cannot be fully defined unless there is some sketch geometry on the plane that is in turn
related to something else. Limited types of sketch relations can be applied directly to the plane
itself. Horizontal and Vertical relations cannot be applied directly to the plane to orient it.
Horizontal and Vertical relations of entities on the plane are relative only to the plane and not to
the rest of the part; therefore, making a line horizontal on the plane does not mean anything when
the plane rotates (which it is free to do until it is somehow constrained to prevent this).Beyond this, when a plane violates a sketch relation, the error is not reported, which severely limits
the amount of confidence that you can place in planes that are created in this way. The biggest
danger is in the plane rotating, because that is the direction in which it is most difficult to fully
lock down. The best recommendation I can make here is to suggest you create reference sketch
lines with relations to something stable, preferably outside of the 3D sketch.If you choose to use these planes to activate the plane for sketching, you can double-click the plane
with the cursor. The plane is activated when it displays a grid. You can double-click an empty
space to return to regular 3D Sketch mode. The main thing that you give up with abandoning 3D
sketch planes is the ability to use the dynamic drag options when all loft or boundary sketches are
made in a single 3D sketch (something I have only used once to demonstrate the idea).