hexagon logo

Best Fit Alignment

I do not use best fit alignments very much, so I am questioning myself. I have a part that the customer print wants it leveled to three nets in the Z axis (datum -A-), then six holes are the used for the -B-, fitting the X and Y axis. This part is being measured in freestate. I measured 12 points (four on each net surf.) and constructed a plane. I measured the six holes and went to the Best Fit in the alignment window, I went to Type: 3D No Rotation, then hit Least squares, clicked all my alignment features, put the weight at 1 for each feature, holes set to X and Y, Pln-A set to Z. I set the deviation threshold to .5mm per the print for the hole tol. then clicked compute. No warnings are in the window. The deviation for the Pln-A is zero, the six holes vary which is expected, readings are .174, .926, .12, .302, .215, .126. I do not have the mmc check fixt. here to check the part, but in general, does my alignment read ok? I know the one hole is out, that will be a review. I just want to know if I am using the correct alignment for this setup? Is there a better best fit iteration? Sometimes you have to question yourself just to make sure its correct, thanks in advance.

Odda
Parents
  • Without seeing the part I have to make the assumption that the holes are perpendicular to Datum A. Datum A will give you enough to level and offset in the Z axis. For the best fit alignment you will want to select the 6 holes, select 2D best fit, make sure Tx, Ty and Rz are checked (Translate in the X+Y axis and Rotate about Z axis), and set the 2D plane to Z Plus.
Reply
  • Without seeing the part I have to make the assumption that the holes are perpendicular to Datum A. Datum A will give you enough to level and offset in the Z axis. For the best fit alignment you will want to select the 6 holes, select 2D best fit, make sure Tx, Ty and Rz are checked (Translate in the X+Y axis and Rotate about Z axis), and set the 2D plane to Z Plus.
Children