Salute all!
We have a Chinese laser cutting machine for tubes and it has been working fine for 2 years but recently we are having serious centralization issues with the cuts specially on rectangular and square profiles. The machine uses TubesPro CAM software and it has a lot of calibration methods for finding the center that measure the distance from each side of the tube. So far it seems that the calibration is working fine because the laser is positioned exactly above the center before starting but during the cutting process it goes off center and all of the holes are around 4 mm to one side.
We have contacted the manufacturer and tried everything. we even used a square tube without chamfered edges to calibrate better but it seems that the problem is really not calibration.
The strange thing is that the holes are exactly in the same position with every cut just not where they should be.

Has anyone had any similar experience? what do you suggest we should check next to find the problem?