What should I do if the tool change point of FANUC is set incorrectly and causes a tool collision

After the Fanuc tool change point is set incorrectly, resulting in a tool collision, the process of "emergency shutdown → status check → fault reset → parameter correction → safety verification" should be followed to avoid secondary damage. The specific operation steps are as follows:

Step 1: Emergency shutdown and on-site inspection

Immediately press the ‌ emergency stop button ‌ of the machine tool to cut off the servo power and prevent further damage to the tool, spindle and tool magazine.

Manually rotate the spindle to check if the tool is stuck and if the tool holder is deformed. At the same time, inspect the appearance damage of the workpiece, fixture, and tool magazine manipulator. Record the program segment and current coordinates when the tool collision occurs.

Step Two: Get out of the stuck state

After confirming that the emergency stop is effective, switch to ‌ manual/handwheel mode ‌, and slowly move the Z-axis at the lowest magnification to safely remove the tool from the collision position. Observe the force state throughout the process and do not forcibly drag.

If the mechanical hand gets stuck and cannot move, you can release the brake of the mechanical arm motor and manually rotate the mechanical arm to the safe return position with a wrench to avoid damaging the transmission components due to hard bending.

Step 3: Core status check after the knife collision

Check if there are any scratches on the taper hole of the main shaft and if the pull pins are loose. Manually rotate the main shaft to confirm that there is no jamming or abnormal noise.

Check whether the mechanical origin of the machine tool has shifted, re-execute the zero return operation of each axis, and confirm that the zero position of the encoder has not been lost.

Check the positioning accuracy of the tool magazine tool holder and confirm that the origin position of the tool changing arm has not shifted.

Step 4: Correct the incorrect tool change point parameters

Switch to MDI mode, enable parameter write permission, find ‌ parameter 1241‌ (second reference point tool change coordinate), delete the previous incorrect value.

Manually move the tool rest to a safe tool change position without interference, record the current mechanical coordinate values of the X and Z axes, and re-write these values into the corresponding fields of parameter 1241.

Confirm that the value of the spindle orientation parameter 4077 is consistent with the original backup before the tool collision to avoid the spindle positioning Angle deviation.

Step 5: Safety verification and resumption of production

Turn off the parameter write protection and conduct more than three no-load tool change tests first. Observe throughout the process that the tool change action is smooth without any lag or interference.

Verify the machining accuracy by trial cutting with scrap materials and confirm that the tool compensation and workpiece coordinate system values have not shifted due to tool collision.

After confirming that all components are in normal condition, resume formal processing.

Key tips for avoiding pitfalls

After a tool collision, it is strictly prohibited to directly restart the machine tool and continue running the program. The mechanical accuracy check must be completed first to avoid residual jamming hazards that may cause secondary tool collisions.

Before modifying all parameters, it is essential to back up the original values. If the zero point is lost due to tool collision, the reference position can be quickly restored by backing up the parameters.