https://youtu.be/nVL4GOr3ff0 After publishing "Marblevator, Wheels", YouTube follower RobotHut (https://www.youtube.com/user/Robothut) commented regarding the use of "cones" in the wheels as opposed to "cylinders". By using cones, he explained, the model could remain vertical during operation as opposed to being tilted rearward, and the cone shape would provide the slope necessary to transfer the ball bearing from the front wheel, to the rear wheel, then to the base. So here it is, "Marblevator, Wheels, Vertical" standing vertical and using cones in the wheels as opposed to cylinders. In the linked three part video, the cad model, assembly process and operation are shown. Designed using Autodesk Fusion 360, sliced using Ultimaker Cura 4.1, and 3D printed in PLA on Ultimaker S5s.