Hi Bryan, a couple of ideas:

re:
> I can't seem to delete the upper part of the cone...

If you're running the current v5 beta (https://moi3d.com/beta.htm) you should be able to select the upper cone face and use Shift+Delete to remove it and fill in the opening.

Or before you boolean the sphere and cone you could draw a line in one of the elevation views corresponding to this level:





Then select the cone and run Construct > Boolean > Difference, and then select the line as the cutting object.

The cone will be split into 2 pieces and then delete the part with the apex point before using the sphere.

But probably better than that since you're working on matching a 2D spec, it would be easier to do all the work in 2D.

To do that you would prepare 3 curves like this - 2 lines and an arc. The vertical line will end up making the cylinder, the sloped line will make the cone and the arc will make a sphere.



When you have the curves prepared you can select them all and run Construct >Revolve, and pick 2 points on the z axis for the revolve axis and you shouldn't need to do any further work on solids.







- Michael