[Figzyy]

Good day!

I’m working with an old Biesse Rover 346.
When doing a side drilling operation a couple of times i realized the holes aren’t getting drilled in the center anymore, but rather too high.
The problem persists when doing milling or drilling vertical holes. So it seems it’s the whole “carriage” is misbehaving.

First time running a program it runs correct, but if I restart the same program it will have moved the Z-Axis 1-2mm up.
The DRO still reads the correct value, but the cutting bit is not at the right Z-Height. If I recalibrate the machine it starts cutting correctly then wanders off again when running it the second or third time.


My guesses so far is that it’s related to the vacuum system since the computer still reads the correct z height when it’s drilling in the wrong spot. But I haven’t found anything to support this theory so far, maybe I just haven’t looked in the right places?

Any help getting me in the right direction would be greatly appreciated!

Ps: new to the industry and terminology, and not natively speaking English so I must excuse any mistakes and or errors that may cause confusion

[mateusedl]

talvez a polia esteja com desgaste

[Algirdas]

Stop production.
Check the accuracy, repeatability without load.
Check with load.