not sure if this is a limitation of Tinkercad, or if I am doing something wrong. I have created a dome as in shape 1, but I want to split it into 2 parts. I am looking to make a removable T shaped cap so I used a couple of rectangles to make the holes and arrived at shape 2. I then took shape 2 and turned that into a hole, then used this as a negative on shape 1 to create what I hoped was going to be the cap (shape 4). but as you can see shape 4 looks crap. not at all what I was hoping for.