Ok, I have read the post regarding this so called argument that my boss and I got into today. He told me that you cannot measure true position in 3 axis, as I told him he was wrong. I know it depends on the way the FCF calls it out, but I tried to explain to him that it is possible to measure TP in 3 axis.
I have seen the formulas, so I know it's possible. I just wish I could get one of you gurus to reply back explaining that it is possible and why. I see the picture but he does not. I do not like to get into pissing matches with upper management, but I have learned a h**ll of alot from you guys, and I know this is possible. So if one of you fine gentleman can back me up on this, I would very much appreciate it. Thank you very much.
Now I am going to get a cold beer.
Maybe it's too early in the morning but I still see NO way to locate a spherical tolerance zone with one BASIC
unless as you illustrated there are ASSUMED dimensions as in coaxiality. The point I am trying to make is that you have to LOCK three Axis in place
somehow to be able to use a spherical tolerance zone. You have to LOCK two axis in place for a diametric tolerance zone etc. No way around it. I don't see the shape of the feature as having any special significance. Example: A tooling Ball. Put it in space in any reference frame. Give it a locator in one axis ONLY and there is no way you can tolerance it with a spherical tolerance zone. The center point of a spherical tolerance zone MUST be pinpointed in all three axis. Unless all three axis converge on a theoretical center point there is no way to determine deviation from that point. Same goes with a diametric. It has to be locked in two axis in a given workplane to be able to determine deviation from the theoretical center.
I do agree that there are times that there are three BASIC Dims locating a feature and there is only a diametric zone. However, you cannot USE all three to axis deviations calculate the vector deviation. With a diametric zone you can ONLY use two axis to calculate deviation OR you are constraining the feature to a spherical zone.
That said, what is your criteria for determining workplane when performing diametric TP tolerancing when there are three or even four BASIC Dims?
Maybe it's too early in the morning but I still see NO way to locate a spherical tolerance zone with one BASIC
unless as you illustrated there are ASSUMED dimensions as in coaxiality. The point I am trying to make is that you have to LOCK three Axis in place
somehow to be able to use a spherical tolerance zone. You have to LOCK two axis in place for a diametric tolerance zone etc. No way around it. I don't see the shape of the feature as having any special significance. Example: A tooling Ball. Put it in space in any reference frame. Give it a locator in one axis ONLY and there is no way you can tolerance it with a spherical tolerance zone. The center point of a spherical tolerance zone MUST be pinpointed in all three axis. Unless all three axis converge on a theoretical center point there is no way to determine deviation from that point. Same goes with a diametric. It has to be locked in two axis in a given workplane to be able to determine deviation from the theoretical center.
I do agree that there are times that there are three BASIC Dims locating a feature and there is only a diametric zone. However, you cannot USE all three to axis deviations calculate the vector deviation. With a diametric zone you can ONLY use two axis to calculate deviation OR you are constraining the feature to a spherical zone.
That said, what is your criteria for determining workplane when performing diametric TP tolerancing when there are three or even four BASIC Dims?