I have a rectangular fixture with 4 corner alignment blocks. The fixture is engraved with the coordinates for the outermost corner of each block. For each block I create a measured plane by taking 3 hits on top of the block. I then create a line on each of the outer sides of the block and intersect those lines. Next, I project the intersected point to the plane creating a projection point which represents the engraved coordinate location (outermost block corner). I do this for all four blocks and then create a best fit least squares plane from the 4 corner points. My constructed plane is within .003 MM of nominal. After creating the alignment and go back and take a confirmation point on top of each block I see as much as .2 MM deviation from nominal. As I stated I am creating a best fit plane but I expected to see the top of each block closer to nominal. Do you see any issues with the way I have gone about creating the alignment? Any observations or recommendations here would be appreciated.
Alignment Plane Construction (Tooling Blocks)
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3 Points fro a plane = a perfect plane solution nothing is perfect check intersection lines and points and see where error is. I would add a point to all planes and verify each plane and intersection for deviation from nominal and try to find the measurement error How perfect are engraved coordinate numbers?
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