How to construct a dome?

Alohaa · 20 Dec 2022, 09:03

Hello,

around the central vertical line in the attached file I want to construct a dome with a hollow star-shaped object going vertically through the whole material.
The purpose: a roof for the tower also contained in the file.
Note: the construction should change from a rectangular ground plan that fits inside the top of the tower to a circle.
The dome should protrude 5mm from the side of the tower.
All my attempts to construct such an object have failed so far.

Actually, I would also like to add one or more moons on the side that fits the curvature and that goes vertically (it has to be vertical because I want to mill the whole thing and I can't mill at an angle), through the whole material, but that is even more complicated and probably too complicated.

Sincerely
Alohaa

Kuppel.skp

Alohaa · 20 Dec 2022, 10:20

...and ideally the dome would be hollow, with a wall thickness of 8mm.

samodelkin_77 · 20 Dec 2022, 12:44

I'm not sure I understood you correctly, but suddenly I guessed right))

Kuppel 1,1.skp

Alohaa · 20 Dec 2022, 16:46

Thank you very much for all that work!
It's almost what I wanted. The only thing I had imagined differently: at the bottom it should start as a square and stand about 5mm above the edge of the tower, and then go into a curve; the base should be like in the attached picture - I didn't find a better example-, at the top of course different because there is a star-shaped cut-out there. I don't know if this is possible with SU.

Alohaa · 29 Dec 2022, 14:48

I managed to construct a dome myself, but probably in a more complicated way than SU allows. There's probably a simpler solution of copying the inside of the dome and enlarging it to construct the outside; I drew both line by line, and it eventually worked out.
Above I cut out a star, but I didn't know how to put it on the dome, so I created a separate GCode for the star.

Dome.skp

HornOxx · 29 Dec 2022, 15:24

...just as a suggestion Alohaa - if you downsave your SKP file posted here, e.g. to version SkUp 2017, you would give almost everyone here the opportunity to deal with your questions

ely862me · 29 Dec 2022, 15:39

Once you have the desired profile shape you can use follow me. An then intersect geometry to subtract the star shape. But I believe your method is better when working with the cnc. Mill the star afterwards.

Alohaa · 29 Dec 2022, 16:45

"downsave your SKP file posted here"
oh yes, sorry, I had forgotten that

The follow me method is indeed much more efficient.
I should try if the mill has a problem with a structure generated by that method.

Dome 2017.skp