An employee was manually rotating a 3 3/4-inch hand wheel on a new slat conveyor as part of an adjustment process. There was a gap at the bottom of the wheel and the wheel-holding bracket. While rotating the wheel, the stem dislodged from the holding bracket and the wheel shifted downward, causing the gap to close and pinch the tip of the employee's right little finger. The employee's fingertip was surgically reattached.