Creating a 3D Elipse.

[PotGuy]

Hey all.

 

Making a spoon for ReMark (Long Story, Link) and I've come unstuck.

 

I need to make an elipse that's cut in half, and I have no prior 3D experience that's useful to create this shape.

 

Any suggestions?

 

(Wonder if'll shut off this thread so I have do do it alone! )

[ReMark]

Is this what you had in mind?

 

The closed polyline profile was REVOLVED around the Object which in this case was just a straight line. The result is a solid.

[PotGuy]

[ATTACH=CONFIG]39899[/ATTACH]

Is this what you had in mind?

 

The closed polyline profile was REVOLVED around the Object which in this case was just a straight line. The result is a solid.

 

Yes, but I have no clue as to doing this. I'm up to the 2nd stage.

 

I can't work on it now as I can't access file.

[ReMark]

An arc can be used as well. Forget using an arc. My bad.

 

No clue? You do see the series of steps I laid out right? And I did mention I used a closed profile (individual polylines joined together as one continuous line). After which one invokes the REVOLVE command. I elected to revolve the profile around an object (which is an option) and that object was a single straight line as seen in the image above. Then it is just a matter of telling AutoCAD to revolve a full 360 degrees or something less than that. Pretty straight forward. Give it a try. BTW...do you know how to change your view to one of the four default isometric views? You might want to switch over to a 3D modeling workspace too for access to other 3D modeling commands. Do you also know how to manipulate the UCS? Could come in handy too.

Edited January 25, 2013 by ReMark

[PotGuy]

An arc can be used as well.

 

No clue? You do see the series of steps I laid out right? And I did mention I used a closed profile (individual polylines joined together as one continuous line). After which one invokes the REVOLVE command. I elected to revolve the profile around an object (which is an option) and that object was a single straight line as seen in the image above. Then it is just a matter of telling AutoCAD to revolve a full 360 degrees or something less than that. Pretty straight forward. Give it a try. BTW...do you know how to change your view to one of the four default isometric views? You might want to switch over to a 3D modeling workspace too for access to other 3D modeling commands. Do you also know how to manipulate the UCS? Could come in handy too.

 

I can manipulate the UCS, Use the Viewcube and switched to Basic 3D.

[ReMark]

That's good. What about the rest of my instructions? Are you clear on them as well?

[PotGuy]

No, I'm afraid I can't proceed after Step 2 as I don't have the knowledge to manipulate shapes to do that. May DL AutoCAD 2012 to my PC as I'm a Student.

 

8GB Ram

 

I5 - 3570k CPU w/ 3.4 G/h.

 

Geforce GTX 670

 

This acceptable / Intermediate for CAD use for 2D / Small 3D?

[ReMark]

Let's back up a bit.

 

Are you familiar with the ellipse command?

 

Are you familiar with the Pedit command and joining lines/polylines into a single entity?

 

Your computer setup should be more than adequate for creating a 3D spoon.

 

Actually we can skip all this (using an ellipse) if you'd like and I'll show you a different method.

Edited January 25, 2013 by ReMark

[PotGuy]

Let's back up a bit.

 

Are you familiar with the ellipse command?

 

Are you familiar with the Pedit command and joining lines/polylines into a single entity?

 

Your computer setup should be more than adequate for creating a 3D spoon.

 

Actually we can skip all this (using an ellipse) if you'd like and I'll show you a different method.

 

I'm familiar in using an Elipse and its variants, including ellipse arc.

 

I'm comfortable in joining, editing etc. PLines and using the PE command.

 

My concern is adapting the PLine and Elipse to a 3D environment, as I am not familiar nor have prior useable experience with it.

[the downing effect]

Even in the 3-d environment you still only draw on a 2-d plane. Then you use one of the commands such as extrude, revolve, sweep etc to turn the 2-d sketch into a 3-d object.

 

This won't help with the spoon but it will help you understand the revolve command a little more.

Draw an elipse and split it in half with a line and trim one side of the arc off, you should have a 'D' shape. Then make sure you are in 3-d basics or 3-d modeling (I prefer 3-d modeling) workspace. In the top left of the drawing area you should see '2-d wireframe' click this and switch to conceptual. Next click the 'revolve' command, it'll ask you select an object, select the ellipse hit enter: then it'll ask you for an axis, select the top and bottom endpoints of the line: finally it'll ask you for the degrees to rotate select 180, 360 or whatever you want and hit enter.

[PotGuy]

Even in the 3-d environment you still only draw on a 2-d plane. Then you use one of the commands such as extrude, revolve, sweep etc to turn the 2-d sketch into a 3-d object.

 

This won't help with the spoon but it will help you understand the revolve command a little more.

Draw an elipse and split it in half with a line and trim one side of the arc off, you should have a 'D' shape. Then make sure you are in 3-d basics or 3-d modeling (I prefer 3-d modeling) workspace. In the top left of the drawing area you should see '2-d wireframe' click this and switch to conceptual. Next click the 'revolve' command, it'll ask you select an object, select the ellipse hit enter: then it'll ask you for an axis, select the top and bottom endpoints of the line: finally it'll ask you for the degrees to rotate select 180, 360 or whatever you want and hit enter.

 

Thank you for the comprehensive answer.

[Isham_Dean21]

it will not let me make an elipse a polyline...why?

[Isham_Dean21]

i swear, i never find the answer until AFTER i FINALLY ask it...i found your comment on another Thread ReMark about "PELLIPSE" and setting it to be "1"...worked like a charm. thanks!!!

[ReMark]

I do my best work in absentia. LoL

 

You're entirely welcomed.