A Revolve Question

[RogerInHawaii]

I have a plane (actually the surface of an existing object) on which I produced a sketch. I selected to do a Revolve using that sketch BUT I selected as the axis of the revolve the actual vertical axis of the 3D environment. That is, NOT a line or axis within the sketch itself. It seems to accept he fact that I accepted that at the axis of revolution. It did not give me any warnings or errors indicating that it might not be allowed.

But when it shows the Revolve that it's about to do, it is NOT revolving around the selected axis. It appears as though it's somehow selecting something from the sketch plane, maybe an edge, or maybe it's "projecting" the selected axis (which is NOT within the sketch plane) ONTO the sketch plane and using that as the axis.

I've included a simple example of what's happening.

That just seems very weird to me. It's certainly not what I wanted or expected it to do. Are rotation axis actually RESTRICTED to being within the plane of the sketch? If so, I would expect that either it give an error if a non-plane line or axis is selected for the axis OR that it show on the sketch plane WHAT it's actually going to use as the axis, with maybe an advisory message that it's shifted the axis onto the plane.

And, by the way, every once in a while when I'm specifying arguments for a Revolve, the dialog will show Type as Full but still show the Angle edit field. Usually the Angle field just disappears when Full is selected, but other times it's still there.

[etfrench]

There are no axes other than the origin axes in your file.

[RogerInHawaii]

That doesn't answer the question. The Revolve dialog allows me to select an AXIS as the axis of revoluion. It also allows for the selection of a LINE within a sketch, but in this case I've actually selected one of the axis of the project's overall origin. Yet when it performs the revolution it does NOT use the axis that I specified but instead uses something else, possibly a line it finds in the sketch or perhaps some kind of projection of the selected axis ONTO the sketch.

It APPEARS that it implicitly restricts the axis of revolution to being a line or axis that's located within the 2D sketch. But the overall origin axis that's displayed and selectable may not be ON the sketch. The sketch itself can be at any crazy angle relative to the overall 3D planes. But I may want that 2D sketch to revolve around one of the 3D origin's axis. It seems to allow me to select one of those, but it doesn't actually do the revolve around it.

In the above diagram the axis that I selected was the vertical GREEN line, but instead it did the revolve around the grey/white line. I have no idea where it got that grey/white line and decided to do the revolve around it.

If Revolve insists on the selected axis of revolution being actually ON the sketch, then it should not allow for the user to select any of the 3D origin's axis when they're not coincident with  the sketch.

[etfrench]

It projects the axis to the sketch plane.  What shape would you expect to get if it didn't?

p.s. Revolving can be fun:

[davebYYPCU]

I think you have demonstrated that the revolve command is a 2d command, the axis to be in the same sketch or on the same plane, if from elsewhere.

Fusion demos the anticipated cut with the Preview, but you complain that this preview is not what you asked for, (a 3d revolve.)  Fusion is smart enough to work within its own programming and gets you this far, if not right - cancel, and prepare again.  

Plane on an angle from the Y Axis, and a new profile, or 

Sweeps can be 3d, Create the path around the Y axis for a Sweep.  Path has to have an association with the profile.

Might help....

[RogerInHawaii]

I would say that from a User Interface standpoint if a 3D program allows the user to select one of the 3D axis it is perfectly reasonable to expect the revolve to occur around that axis, in the 3D space. Having it instead project the selected axis onto the sketch's plane is not particularly intuitive. I do realize that it provides a preview of what it will actually do and it does show a representation of the projected axis, but it is not intuitively obvious that the Revolve operation, which is inherently 3D, is restricted in terms of its axis of revolution to the 2D sketch plane.

[etfrench]

You haven't defined what shape you expect when the axis is not on the sketch plane.  It must be distorted from the shape drawn on the sketch.  I think you'll find that is the reason the axis is projected to the sketch (or body face) plane.

[davebYYPCU]

[chrisplyler]

---

@RogerInHawaii wrote:

I would say that from a User Interface standpoint if a 3D program allows the user to select one of the 3D axis it is perfectly reasonable to expect the revolve to occur around that axis, in the 3D space. Having it instead project the selected axis onto the sketch's plane is not particularly intuitive. I do realize that it provides a preview of what it will actually do and it does show a representation of the projected axis, but it is not intuitively obvious that the Revolve operation, which is inherently 3D, is restricted in terms of its axis of revolution to the 2D sketch plane.

---

Totally agree. But also don't think it's that big of a deal. I learned it the first time I tried it, and since then plan to produce my geometry according to the Fusion DOES work.

[TrippyLighting · Accepted solution]

I agree with that assessment as well. While I is customary in CAD software other non CAD 3D  modeling software does not require that the revolve axis is in plane with the revolve profile and perform revolves happily.