Any CMM experts out there who can help answer a question would be greatly appreciated.
Here is the situation. We are measuring a round part (OD). First measurement with a 2mm probe tip we get one measurement. When we try with a 1.5mm probe tip, we get a .002+ difference -- the diameter is larger. We are measuring in the same spot with the same setup. When we check both tips against a gage pin, they both check the pin accurately.
The part is draw formed so the wall is not perfect. We suspect that has something to do with the measurements. But we can't figure out why. Logically, we would think the larger ball would cause bigger diameter as there is more surface area to pick up high spots. But that is not the case. Any thoughts? Thanks in advance.
Here is the situation. We are measuring a round part (OD). First measurement with a 2mm probe tip we get one measurement. When we try with a 1.5mm probe tip, we get a .002+ difference -- the diameter is larger. We are measuring in the same spot with the same setup. When we check both tips against a gage pin, they both check the pin accurately.
The part is draw formed so the wall is not perfect. We suspect that has something to do with the measurements. But we can't figure out why. Logically, we would think the larger ball would cause bigger diameter as there is more surface area to pick up high spots. But that is not the case. Any thoughts? Thanks in advance.