Adjusting ATC Cam Wheel

This adjustment is performed when the ATC arm drifts or does not stop consistently at the beginning or end of its rotation.

Before adjusting the signal wheels, verify that the ATC motor brake is fully engaged and operating correctly.

The ATC arm uses two signal wheels to control position sensing during the tool change:

Left Wheel = Brake Signal Wheel

Right Wheel = Cam Signal Wheel

Each wheel rotates past a fixed sensor block containing three sensors. These sensors detect the arm’s position and trigger the next motion in the ATC sequence.

The Brake Signal Wheel should always be adjusted first. The wheels are secured to the arm shaft by green-circled set screws, loosening the screws allows each wheel to rotate independently of the shaft for fine timing adjustments.

Left screws adjust the Brake Signal Wheel, Right screws adjust the Cam Signal Wheel

Loosen the left-side set screws on the Brake Signal Wheel.

Adjust the timing by moving the wheel slightly UP or DOWN:

Brake engages too early? Move the brake wheel UP.

Brake engages too late? Move the brake wheel DOWN.

Use the two timing reference marks on the wheels as the default starting point — these are small gray dash indents on the wheel edges, shown in blue in the picture for clarity.

Tighten the set screws and verify the brake engages and holds correctly at both the start and end of the ATC arm motion.

This adjustment should only be performed if correcting the Brake Signal Wheel timing did not resolve the issue.

Confirm the ATC arm is already in the Home Position — centered between the spindle and the tool pot. This is the default stopping point after a completed tool change.

Loosen the right-side set screws on the Cam Signal Wheel.

Rotate the Cam Signal Wheel until only the center sensor (2) is lit. This typically places the wheel’s arrow between the two small red reference marks.

Tighten the set screws and verify that the middle sensor switches cleanly on and off as the arm enters and exits the Home Position.