Help with geometry (A dome with rectangular fins)

[vadiraj666]

Hi,

I recently started working on AutoCAD 3D. I need to make a solid model of a dome with rectangular fins on its outer surface. I have attempted it and a picture of the model is attached. My problem is that the top surface of the fins is curved (because of the method I adopted) while I need it to be flat. Also I am not sure if I am doing it the right way or if there is some other better way to go about it. This is how I made the model.

• First I made a hollow sphere (by subtracting one solid sphere from another)
  
• I created a box and subtracted it from the hollow sphere to get the dome.
  
• Created an array of box with width = width of fins.
  
• Created one more larger hollow dome and used the intersection of that dome and the array of boxes to get the final geometry (thus resulting in a curved top surface of the fins)

I also need to know whether solids obtained by 'revolve' command are 'true' solids (so that it could be exported to other softwares for simulations).

Any help in this regard will be highly appreciated.

[Patrick Hughes]

A solid created by the revolve command will indeed be a true solid. In fact my suggestion was going to be to create your profile first in 2d, turn into a pline and revolve.

[Red333]

A solid created by the revolve command will indeed be a true solid. In fact my suggestion was going to be to create your profile first in 2d, turn into a pline and revolve.

I agree. Revolving a polyline is the way to go here.

[ReMark]

Is this what you had in mind?

 

 

As you can see the ring in flat across the top.

[shift1313]

i third the revolve option. It would be the easiest way to achieve what you want.

[vadiraj666]

Thankyou everybody. That was easy.