Attempting to create a dome - SOLVED

[luggw1]

OS: Linux Mint 20
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.4.
Build type: Release
Python version: 3.8.2
Qt version: 5.12.8
Coin version: 4.0.0
OCC version: 7.3.0
Locale: English/United States (en_US)

I'm attempting to create a model of a dome I can have 3D printed for a model I'm building. My thought is if I can get 1/4 of it modelled, I can mirror it and union the parts together to get the whole thing put together.

As you can see from the model I've attached, I've got a couple of profiles that represent the cross section of the dome where it sits on the boiler and transverse to the boiler. I also used some arcs and lines to construct a surface that allowed me to establish the intersection curve between the dome and the boiler (the section). My problem is that I can't seem to get any of the construction tools to behave properly. It seemed like the Sweep tool is the one I wanted to use with the multisection Transform mode, but the result is anything, but what I want. It seems to generate an extra cusp on one of the flat sides if I start with the OnBoilerProfileSketch, then add the OffBoilerProfileSketch and finally add the Section curve - obviously not what I want.

I also tried the Loft, but that doesn't offer the ability to select a curve to trace the profile along - not useful in this situation it appears.

So, my question is what am I doing wrong? this doesn't seem like it should be that difficult for the S/W to perform. Is there something wrong with my sketches that's causing this?

The frustrating thing is that I was successfully able to complete this task for the more complex steam dome some time ago (see screen shot, the model is too big to attach).

Any help would be greatly appreciated.

Thanks
Bill Lugg

[Willem]

Approximately 2 years ago I made this dome

[chrisb]

You cannot make a sweep, where the edges of the sections touch, because this causes self intersections of the sweep. Make as much as you can with a revolve, and add the missing irregular sections with the sweep.

[papyblaise]

As Willem
Do a 1/4 Dome , do the section of the fillet at each end and sweep to use the joinction line as path
To do a 1/4 dome : no risque of autointersection
Then do 2 miror

[luggw1]

Well after being away on a trip for a week I came back and attempted the recommendations of chrisb and papyblaise. I had the most success with the latter getting a product that meets most of the requirements. Unfortunately I could never get the sweep to behave quite the way I wanted it to, but the fillet around the base produced acceptable results.

Thanks to everyone for your assistance.
Bill Lugg