Use the supplied original cam and guided roller schematic. Lock the camera, dark cam hub and two vertical stem guides. Rotate the same ochre cam slowly so its rising flank passes under the teal roller, lifting the attached stem vertically. Keep the roller against the visible contour. As the broad high circular arc passes beneath it, keep the follower briefly near the same high position while the coral cam mark continues turning. Then let the falling flank lower the follower toward its starting height, still in contact. Keep the cam profile rigid, the stem inside its guides and the roller attached to the stem. No connecting rod, floating gap, sideward stem motion, extra lobe or camera move. End after this one rise, dwell and return, with all original parts visible.