Unable to reference plane origins. 1

[KirbyWan]

Howdy all,

I have a question about plane origins. If I open a sketch on a plane whose origin is not coincident with the part origin I can not reference it. There are work arounds, such as placing a point at (0,0) and fixing it, but is there some reason the plane origins can't be used as a reference? It just seems kind of obvious to me. I included a part with a set of planes and sketches to show my point. The front plane and plane1 have the plane origin coincident with the part origin so I can reference those. Plane2 to is on an axis that does not go through the origin and so the plane origin is not coincident with the part origin. I can reference the part origin still but not the plane origin. I also did the trick to make a plane normal to the current view and the origin of that plane was set coincident with the origin so that one could be referenced.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[CorBlimeyLimey]

Reference Planes do not have origins!

A sketch created on a plane or face does have an origin (of sorts), but it is only visual placemark to show the relationship of the sketch to the global origin. The sketch origin is not really selectable, but appears to be when 'attaching' sketch elements to it. However when using the Display/Delete Relations tool and selecting the end point of a line (which is on the sketch origin), you should notice that the global origin is actually highlighted.

When the sketch plane is set to Normal view, the origins line up and it appears the sketch origin is selectable, but it is really the global origin being selected.


FYI, it has always been that way.

 

[KirbyWan]

CBL,

Normally the reference plane origin is coincident with the part origin when looking normal to it, but not always. That was my point with plane2 and sketch3 which is on plane2. If you look at the origin, it is not coincident with the part origin. Perhaps I'm getting confused between sketch origin and reference plane origin. But I dropped a point on the sketch origin at (0,0) and when looking normal to the plane it does not coincide with the part origin when looking normal at it. The original reason I brought this up was because in the properties dialog for plane2 there is an option to 'set origin on curve' when perpendicular to axis is the constraint. but the origin is the same either way, and if I could set the origin where I want it why can't I dimension from it? What does this flag change when 'set origin on curve' is selected? And I wonder why use the term curve since an axis is straight, but I'm assuming you could be selecting a curve on which you want a perpenicular reference plane.

Thanks,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[CorBlimeyLimey]

Using a curve or axis appears to be a special case where an origin is pre-assigned at the end of the curve or axis.

Create a cube, activate the Plane manager, select an edge and a vertex not associated with the edge, then toggle the Set origin on curve option to see what happens.
Also check out the Help file

http://help.solidworks.com/2012/English/solidworks/sldworks/hidd_dve_create_plane.htm

Even more interesting is what happens if a solid body is created from the plane, and then the Set origin on curve option is toggled. The solid body moves with the origin.

 

[KirbyWan]

I see what the difference is. Since the point I select is the endpoint of the axis the sketch origin ends up being the same. Thanks CBL.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[jassco]

Hi, Kirby:

Good observation!

FYI, a plane have no origin. An axis has no end points. If you want to reference your new "origin", you need to show your sketch1.

I think it would be a good enhancement if SW has this feature.

Best regards,

Alex