A remix of Sapper 12A's design. I kept breaking the towers off, so I added more thickness to the joint.

I’m new to 3D design so I had a hell of a time figuring out how to reinforce that one point. Most of my efforts were unacceptable. What finally worked in the end was importing a cone shape, reducing its complexity until it had only 8 sides, and sizing it to fight the underside of the tower. Boom, done. I learn something new every day.