Center of Gravity in Miter Cuts Wrong Values??

Discussion created by 1-J0IC7K on Jul 10, 2009
This may seem petty - but im going to post anyway This is a simplified version of a larger weldment.

I have a simple square 18" x 18" weldment made of 2 x 2 x 1/4" Angle - all corners are mitered. When I look at the mass properties and then the Center of mass I noticed that there are errors in the coordinates.

I understand that the Y coordinate should be something greater than 0 and less than 2, but my X and Z coordinate should be 0.000000000. They are off on about the 5th decimal place... 0.00000875 or so.

[1] When I take the mitered cuts away, my X and Z coordinates go to 0.0000000

[2] If I only miter two adjacent corners, my X and Z coordinates go to 0.0000000

[3] If I miter all four corners, my X and Zcoordinates go to 0.00000875 and -0.00000073 or something similar

[4] note - I am using 2 groups to make the weldment - and a post trim/extend feature to make the cuts.

Anyone know what I'm doing wrong??