If you find the blue laser can not focus on the center of the processed cylinder when using the chuck to hold it. It is likely because the chuck is not installed on the holder properly.

Remove the chuck, and install it again properly.

In the following, the Maximum Diameter of Processing Material Under Different Modes for Rotary Attachment is listed for your reference：

The maximum diameter is 88mm in Roller mode as shown in the left picture.

The maximum diameter is 83mm when the chuck is assembled in the holder's direction shown in the right picture.

 

The maximum diameter is 100mm when the chuck is assembled against the holder's direction and the material is held as shown in the left picture.

The maximum diameter is 113mm when the chuck is assembled against the holder's direction and the material is held as shown in the right picture. F1 needs to be lifted 6.9mm in this mode.