Figure 5. Moving the camera sled. Top Left: Manual macro rail. Top Right: Macro rail mounted under and connected to the camera sled. Bottom Left: Macro rail attached to a stepper motor with a 3D-printed pulley and a timing belt. Bottom Right: Stepper motor control unit with two forward step options and a rewind button.
Figure 6. Rig in use. Note monitor for tracking focus. Camera and lens below; lights and subject to the right.