hexagon logo

How straight is a row of holes.

Hi. I'm new to PC DMIS (fresh from a class). We are using 15.1 and have a Romer Arm, currently with a 3mm probe. Here's what I was asked to measure:

A row of 70 drilled holes (.25" dia, spaced 1.5"). This row was placed in the .31" thick material with no reference is an edge, datum or otherwise. There is no design print. It's just a row of holes. The Engineer wants hole spacing (I've done that). He also wants to know if the holes are in a straight line. He wants the deviation from each hole center point to a line created between the first and last hole centers. So, I constructed a BF line between the first and last holes. Then I measure from that line to each hole center. Problem is this.. I would expect to see zero for the distance between the line and the first and last hole centers. But I am seeing 0.0392" for both.
I aligned the material multiple times and this does not seem to significantly impact the results (Plane, Circle, Circle; Plane Cyl, Cyl; and currently at Plane, Line Point).
I appreciate greatly the assist and any suggestions that may come for the forum.
Parents
  • VIEW ~ OTHER WINDOWS ~ QUICK START
    Select ALIGNMENT, pick PLANE-HOLE-HOLE

    Measure the plane on top of the part, measure the "left" hole, measure the "right" hole

    You are now aligned level to the top, rotated to the line between the 2 holes, origin on the first hole and top (6 DOF)

    Measure the holes in between the 'left' hole and the 'right' hole, report the XY of each.

    This will tell you the spacing (X) and how far out of straight they are (Y)

    Pretty simple.
Reply
  • VIEW ~ OTHER WINDOWS ~ QUICK START
    Select ALIGNMENT, pick PLANE-HOLE-HOLE

    Measure the plane on top of the part, measure the "left" hole, measure the "right" hole

    You are now aligned level to the top, rotated to the line between the 2 holes, origin on the first hole and top (6 DOF)

    Measure the holes in between the 'left' hole and the 'right' hole, report the XY of each.

    This will tell you the spacing (X) and how far out of straight they are (Y)

    Pretty simple.
Children