Why is back slash eliminator required for down-milling?

The back slash eliminator is required in down-milling to prevent the cutting tool from lifting away from the workpiece, which can lead to poor surface finish and inaccurate cuts. In down-milling, the cutter rotates against the direction of the workpiece feed, generating a downward force that can cause the tool to disengage if not adequately controlled. The back slash eliminator helps maintain consistent contact between the tool and material, ensuring efficient material removal and minimizing the risk of tool chatter or deflection.