Why my CNC accuracy changed in December?

[MarnieYell]

This month I’ve noticed my CNC parts drifting just enough to be annoying. Soooo Same program, same stock, and the machine has been running fine all year. And now , dimensions are close but not as consistent as they were before.

I havve gone through the usual checks and nothing obvious stands out, which makes me think seasonal changes might be playing a role. Temp swings in the shop are bigger now, and I’m wondering how much that’s affecting accuracy compared to warmer months.

Has anyone dealt with this before, what was the first thing you adjusted to get consistency back during winter?

 

[Alan]

December accuracy drift is something a lot of shops notice once temperatures start swinging. When nothing else changed, it’s natural to look at the environment.

Do you see the drift more at the start of the day or later after the machine’s been running?