Manipulative Calculus is a curriculum development project focused on creating active learning\index{active learning} lessons in calculus courses centered around digitally fabricated 3D models that we put into students’ hands. In these lessons, students are asked to make geometric sense of the concepts learned in the course through problems requiring them to handle, discuss, and sketch on the models. As of this writing, the lessons and models have been in use for several semesters by dozens of instructors and thousands of students. This paper reports on the development of the 3D models and lessons for multivariable calculus, experiences and assessments of their use in the classroom, and efforts to make the curricular materials accessible to other instructors.