View Full Version : creating an egg shaped solid
johnfulwyler
5th Nov 2003, 02:31 am
I am using ACAD 2000 and trying to create a solid that is something like an egg, kind of. What i actually need is an eliptical sphere, if that makes any sense. My only idea was to try and REVOLVE an ellipse around an axis that would go from the bottom and top quadrants of the longer end of the ellipse. It didn't really work out. So if anyone understands what I'm trying to say and can shed some light on this for me, that would be great!
Thanks!
John
gcp310
5th Nov 2003, 02:45 am
draw an elipse then draw a line down the centre,then trim one side of the
centreline so you only have one half.
then revolve the one half around the centre line. thats how i would do it.
G
gcp310
5th Nov 2003, 02:48 am
Oh, you could use arcs to create a profile.
once you have the desired profile use PEDIT to convert the arcs into a polyline and also to join them as one polyline.
Then revolve it around an axis.
G
fuccaro
5th Nov 2003, 07:14 am
You can use the REVOLVE command if the shape is a closed polyline and the shape does not intersect the axis of revolution. So draw a line between two opposite quadrants of the ellipse and slice the ellipe using that line segment as cutting edge. Close the shape by adding the line segnent to the remaining half of the ellipse (usinng PEDIT > JOIN). Now you can use the REVOLVE command.
This is the same thing as G descriebed in the first post, just I added some details and an observation: before you draw the ellipse, set the PELLIPSE system variable to 1.
johnfulwyler
6th Nov 2003, 02:30 am
That was easy enough! The shape came out exactly how i wanted it and I now understand the use of the PELLIPSE function.
Thanks again,
John
Mr T
7th Nov 2003, 10:19 pm
Here's an eggy solid, drawn with closed pline and revolved.
Could have used 2 spheres unioned.
Nick
http://www.eezylearn.pwp.blueyonder.co.uk/images/egg1.jpg
http://www.eezylearn.pwp.blueyonder.co.uk/images/egg2.jpg
Flores
7th Nov 2003, 11:35 pm
Mr T, is AutoCAD Zone your site? I noticed it had the same address as your egg.
http://www.eezylearn.pwp.blueyonder.co.uk
http://www.eezylearn.pwp.blueyonder.co.uk/images/egg1.jpg
Flores
Mr T
8th Nov 2003, 10:22 am
Mr T, is AutoCAD Zone your site? I noticed it had the same address as your egg.
http://www.eezylearn.pwp.blueyonder.co.uk
http://www.eezylearn.pwp.blueyonder.co.uk/images/egg1.jpg
Flores
Aye it is indeed. Not updated much but it's my site. Mainly to showcase my pupils work. They do produce industry standard stuff.
Nick
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