- [Instructor] We're opening up a new drawing now
in this chapter, where we're going to take a look
at some of the other drafting tools available in AutoCAD.
And one of those drafting tools is the ellipse command.
It allows us to draw ellipses that represents circles
in an isometric view, in a 2d drawing.
Now a 2d isometric view is purely representative.
It does not represent or create a 3d model in any way,
but when we have finished this particular drawing
it will look sort of 3d.
If you notice we've got two vertical lines
on the objects layer in the cylinder.dwg file.
What we're going to do is we're going to go
to the ellipse command on the draw panel.
So that's over here, there's draw,
and we click on the fly out here
and we've got center, access end and elliptical arc.
We're going to utilize access end
and it creates an ellipse or an elliptical arc.
Click on access end and what we're going to do
we're going to specify the two access endpoints of the ellipse.
So I'm going to left click here on this endpoint
make sure your object snaps are on.
And then I'm going to left click here on this endpoint.
That's the first axis of the ellipse.
And as I move around now,
can you see?
The ellipse is starting to take shape
and it looks like the top of the cylinder.
I'm going to write click now
and select rotation.
Now I'm going to type in a rotation
around the major axis, of 660 degrees.
Now, the reason I'm doing that
is because then it represents a rotation of 60 degrees,
which is one of the isometric angles.
Isometric angles are 60 and 30.
So, imagine this is an exactly circular top of a cylinder,
and you are looking at it at an angle of 60 degrees
rotated about that axis we've just created.
So when I press enter for that 60 degrees
there's the top face of our cylinder.
Now, I need to create an elliptical arc here.
I don't want the whole ellipse this time.
So what I'm going to do is I'm going to go back up
to the draw panel now, click on the fly out
and select elliptical arc.
Come into the drawing area,
and you'll notice I've got the option
of an access endpoint method
or, I can, you'll notice on the command line,
I've got the center option as well.
I'm not going to use the center option,
I can also right click on select center if I want to.
But I'm just going to specify the two end points again,
bottom of the line, this time,
end point there, left click,
and an end point there, left click.
And as you can see, I'm creating the ellipse again
but I've got a right click again and set the rotation first.
So that's going to be 60 degrees again,
like the top one and press enter.
And you can see the ellipses match,
but I now need to specify the start angle.
Now this is the important bit.
Remember arcs go counter clockwise.
So I need to go counter clockwise, to get this to work.
So how am I going to get this to work?
I need to go from this end point here,
left click, counterclockwise, coming all the way around
to this end point, left click,
and there's my elliptical arc.
And if I zoom out, you can see I've got
what looks like a 2d representation of a cylinder.
And that's it.
That's ellipses in a nutshell,
that's how you draw them in AutoCAD.