Mirroring in 3d: What does each step mean to AutoCAD?

[The Mad Cadder]

Most of what I've seen on the web, explains the procedure to get the task accomplished. But I have yet to find a web site that explains "the meaning" of each click.

 

So..

 

What does each click mean to Autocad?

 

Thanks.

[JD Mather]

Select objects: Means select the objects you want to mirror then hit enter

Specify first point of mirror plane (3 points) any plane can be defined by 3 points

or

Object certain objects (like circles or arcs are planar by definition and therefore can be used to define the mirror plane, other planar objects are planar part faces or planar surfaces (these can be selected in Autodesk Inventor as mirror planes - I havent't checked in Autodesk AutoCAD).

Last planar definition used previously

Zaxis plane is perpendicular to entity used to define Zaxis (line and endpoint might be one example)

View should be obvious - current view

XY/YZ/ZX should be obvious - check your current UCS

 

I remember taking a Geometry class in High School back in '71 of the last century where the definition and creation of planes was discussed. This was long before CAD.

 

If you have trouble figuring out relative to a particular problem - attach your file here.

[The Mad Cadder]

Select objects: Means select the objects you want to mirror then hit enter

Specify first point of mirror plane (3 points) any plane can be defined by 3 points

or

Object certain objects (like circles or arcs are planar by definition and therefore can be used to define the mirror plane, other planar objects are planar part faces or planar surfaces (these can be selected in Autodesk Inventor as mirror planes - I havent't checked in Autodesk AutoCAD).

Last planar definition used previously

Zaxis plane is perpendicular to entity used to define Zaxis (line and endpoint might be one example)

View should be obvious - current view

XY/YZ/ZX should be obvious - check your current UCS

 

I remember taking a Geometry class in High School back in '71 of the last century where the definition and creation of planes was discussed. This was long before CAD.

 

If you have trouble figuring out relative to a particular problem - attach your file here.

 

I can mirror in 2d without a problem, because I understand if you want to mirror to the left, (in 2d) I found I had to use an opposite axis.

 

When mirroring in 3d, I don't have a clear understanding of my actions and their consequences. You could use the 3pt option as an example, since it's the default.

 

I posted before and after dwgs, of a file, that is similar in appearance to the tutorial on mirroring in 3d.

 

That was accomplished, by inserting a line in the middle of the two wedges and mirroring around that plane. For all my effort, I *never* could get the default option to work (to achieve the desired results)

 

I hope that my questions are clear. If not, post back and let me know.

 

Thanks in advance,

 

TMC

 

Could someone please explain that to me?

4 wedges mirrored.dwg

4 WEDGES.dwg

[JD Mather]

I can mirror in 2d without a problem,....

 

I can tell you that I have used 3Dmirror maybe twice since 1987.

The only reason to use 3dmirror is if the desired mirror plane is at some unusual compound angle.

I simply go to an appropriate 2D view perpendicular to the desired mirror axis (set ucs to view) and use the mirror command to mirror my 3D geometry.

So much easier!

[The Mad Cadder]

Thanks JD for the tip,

[The Mad Cadder]

I thought I knew how'd you do it, but,...(its not for the lack of trying.)

 

How do you do what you describe...

 

Thanks.

[JD Mather]

In your 4Wedges file the UCS is not set correclty to do a 2D mirror of 3D solids.

[The Mad Cadder]

In your 4Wedges file the UCS is not set correclty to do a 2D mirror of 3D solids.

 

Sorry, for the late reply, I just noticed your post...

 

Could you explain what the problem is, and how to correct it?

 

Thanks.

 

TMC

[JD Mather]

When I looked at your file yesterday I had trouble even figuring out what you were trying to do.

After sleeping on it I think I have it figured out.

 

Not sure what/where you want your mirror plane - but here are three examples.

Note: the ucs is always set to view.

Edited November 22, 2011 by JD Mather