Hello all, I’m hoping someone more experienced than myself can help me out with an issue in Mcosmos and creating a CMM program. I was only given a crash course over a week from our programmer that was leaving and have a good understanding, but some of the finer points I still don’t get.
I have the program nearly done and I’m just working on calculating the elements for the print out. 95% of them are fine and work, but my true position is messing something up.
It is a TP of 3 through holes to A&B datums. Datum A is the bottom of the part which is a circular port, and Datum B is the ID. I use Datum B initially to set alignment and origin for XY and a top of the part plane for Z origin.
Then a theoretical line going along X to align axis parallel to axis.
To get Datum A, I have to go in through a slot in the fixture and take a few points, moving up in Z when taking them. I can’t hit both sides so I’m taking 5 points along a semicircle, then making a plane with those points.
To get Datum B I’m just using 3 circle/diameter elements and construing a cylinder.
At the end of the program I’m trying to align to these datums, save that as cord system 2 then load the initial coord system 1 for all the other dims/measurements.
However, when I do this, it completely flips my axis’ 180 degrees. First it flips X and Y when I try to align to the cylinder of Datum B, then flips Z when I try to align base plane using the plane of Datum A.
My only thought is that it could be the order in which I use the points to create the plane for Datum A, as the first point is in the middle, then two to the left, then two to the right. But that doesn’t explain the flip of XY when I align to the Cylinder.
My question is why would it flip my axis 180 degrees? Hope this is enough to go on.
I know this is difficult to understand based on text but I’m unable to upload or paste pictures here to help clarify. If you need more info please let me know and I’ll try to explain something in more detail.
I have the program nearly done and I’m just working on calculating the elements for the print out. 95% of them are fine and work, but my true position is messing something up.
It is a TP of 3 through holes to A&B datums. Datum A is the bottom of the part which is a circular port, and Datum B is the ID. I use Datum B initially to set alignment and origin for XY and a top of the part plane for Z origin.
Then a theoretical line going along X to align axis parallel to axis.
To get Datum A, I have to go in through a slot in the fixture and take a few points, moving up in Z when taking them. I can’t hit both sides so I’m taking 5 points along a semicircle, then making a plane with those points.
To get Datum B I’m just using 3 circle/diameter elements and construing a cylinder.
At the end of the program I’m trying to align to these datums, save that as cord system 2 then load the initial coord system 1 for all the other dims/measurements.
However, when I do this, it completely flips my axis’ 180 degrees. First it flips X and Y when I try to align to the cylinder of Datum B, then flips Z when I try to align base plane using the plane of Datum A.
My only thought is that it could be the order in which I use the points to create the plane for Datum A, as the first point is in the middle, then two to the left, then two to the right. But that doesn’t explain the flip of XY when I align to the Cylinder.
My question is why would it flip my axis 180 degrees? Hope this is enough to go on.
I know this is difficult to understand based on text but I’m unable to upload or paste pictures here to help clarify. If you need more info please let me know and I’ll try to explain something in more detail.
