The Vertical Stacker for the Challenge CMT 330 TC Three-Knife Trimmer is an optional finishing accessory designed to automatically collect and organize trimmed materials as they exit the trimmer. After book blocks, sheets, or stacks are precisely cut on all three sides, the vertical stacker receives them and stacks them neatly in an upright or vertical orientation. This system reduces manual handling, minimizes the risk of misalignment or damage, and keeps the workflow organized, especially in medium- to high-volume production environments. By maintaining a consistent, compact stack of trimmed materials, the vertical stacker facilitates easier downstream processing, such as packaging, binding, or transport, while improving overall efficiency, safety, and productivity on the trimming line.