PDA

View Full Version : Draw a circle on a plane not perpendicular to the eye.

tharney
6th Mar 2008, 07:56 pm
Imagine a door stop. One side sits flat on the ground, the other side is perpendicular and vertical. The third side is sloped to fit under the door.

Lets say I want to shoot a hole through the vertical side. Well the vertical side will have a perfect circle, the sloped exist hole will have an elipse. I want to know how to draw the elipse.

Thanks.

GhostRider
6th Mar 2008, 08:23 pm
You trying this in 2D or 3d ? I don't know that I could explain how to do it with any accuracy in 2d, in 3d it fairly simple, just draw a wedge, then ectrude a circle through it and subtract the cylinder from the wedge. you could do it 3d then explode the solids I guess to get just the ellipse.. I'll try to post an example. Ooh I just read your using Civil 3d, Sorry, you probably have similar functions, but this is for vanilla ACAD....
It just won't let me attach the picture had to zip it....

6th Mar 2008, 08:31 pm
do it the old way, with construction lines

draw the side view of your wedge (a triangle shape) and draw your hole going through (2 line 1 diameter apart)

your ellipse will have one diameter equal to the diameter of your hole and the other diameter equal to the vertical, horizontal or perpendicular length of where your "diameter" lines leave the triangle.

tharney
6th Mar 2008, 08:34 pm
I'm not sure about the 2D or 3D. The original drawing was all at elevation 0.00. I've drawn the wedge 3D like I want it. Now I'm trying to get a cylinder (actually a cone) subtracted from that. Thanks.

GhostRider
6th Mar 2008, 08:43 pm
Nice explanation dbroda, this old redneck was scratching his head when i first read it, but now after a second read you make it sound as simple as it is....

Dman2900
6th Mar 2008, 09:50 pm
If you have drawn it in 3D why not just change your ucs to the plane that you are on and just draw a circle in that plane? That is what I would do if it is already in 3D. :wink:

tharney
6th Mar 2008, 09:52 pm
how do I change my UCS to a plane?

Dman2900
6th Mar 2008, 10:01 pm
After thinking about what I said it still would not be true.....you would still need to draw an ellipse in the one plane that is on the sloped side.....:?

tharney
6th Mar 2008, 10:04 pm
Ok, I got that. But how do I change my UCS to a spacific plane, or face of my wedge?

Dman2900
6th Mar 2008, 10:52 pm
Try this......

SLW210
7th Mar 2008, 02:03 am
You could use UCS>Object