The violet carriage is power-fed along the axis of rotation of the workpiece. The orange tool spindle carrying a red tool and a red tracer can slide in the green post that is fixed to the cross slide of the lathe.
The tracer is forced toward the pink sample by a spring. The sample position in relation with the workpiece can be adjusted owing to the violet nut and a conrod of spherical joints (on the right).
Use the green screw of the cross slide to increase the cutting depth. The blue cam is used when moving the tracer to the initial position.