Create a Dome

star50

In Bricscad Shape I would like to create a dome that will be on top of a cylinder.
The height of the dome is less than the radius of the dome, so where it meets the cylinder, it is not at tangent point.

Billie

Hi star50,

Try drawing a cross-section of your shape in 2D first. and then you'll be able to see the center point for the sphere that forms your dome for your cylinder.

All the best,
Billie

Terry Dotson

Have you tried creating a complete sphere, then a box in the area you don't want. Then intersect / subtract the box.

star50

Hi Billie,
I had tried drawing a 2D Arc and drew a chord across the arc, then Join, to make it a closed 2d object, then I rotated it in 3d to make it stand up. Then i tried revolve, I am struggling to get it to revolve about its own center axis. I had some success in revolving it about a remote axis producing a sort of donut.
Thanks for your help.

star50

Hi Terry,
I had tried the complete sphere approach, and i tried to chop off the edges by making a large cylinder with a hole in the middle representing the part i wanted to keep. Extrude as if I was cutting a hole in a solid. My attempt didn't cut the sphere though.
I tried again with your box, intersect, delete method and it worked.
I would have thought that it would be a fairly common requirement to make a cylinder with a dome, (a rivet for instance), that would justify a tool for the purpose.
Thanks for your help.

norb1@bigpond.com

Has anyone tried to fillet a cylinder to create a domed head rivet?
Works for me. Only two moves.

Joe Dunfee

Here is an image showing how I would draft it in 2D.