Oh I forgot to mention that if you want to learn how the joint editor works. This new prop is a great place to start. Simply click on "Show Origin" on the parameter dials window for the top prop and bottom prop. Then open the joint editor from the Menu up top under thw Window selection and move the origin point of each end to the sides of the cylinder and once they're parented to the cylyinder depending on which way you moved the origin you should get lids that open by rotating on either the x, y or z axis.