Ive got a large flange (approx 20" by 14") on which, I've got to measure a hole pattern.
Here is my problem. I've seen this sort of datum callout in books, but never had one to deal with myself. How do you handle the B and C datums? The part material is very thin (.050"). I've got it fixtured to a rayco plate and can reach all the external edges.
What I understood to do was this... (PLEASE CORRECT ME IF I AM OUT IN LEFT FIELD)
1) create plane for datum A (constructed plane from vector points)
2) create three points along the left outer edge
3) create three mirrored points along the right edge.
4) create three MID POINTS for each pair of left/right points from step 2 and 3.
5) Do the exact same thing for the top and bottom outside edges creating three more mid-points.
6) create two 2d lines constructed from the mid-points to get a "center-of-the-part" pair of intersecting 2d lines.
7) align: level to plane A, rotate to long "center" line, origin X at long "center" line, origin y at short "center" line, origin z at plane A.
Or should I be using simulated datums? or is there a way to create these datums of size (+/- .020") some other way that I am not thinking of?
Using 3.7MR3, 1mm ruby tip.
Here is my problem. I've seen this sort of datum callout in books, but never had one to deal with myself. How do you handle the B and C datums? The part material is very thin (.050"). I've got it fixtured to a rayco plate and can reach all the external edges.
What I understood to do was this... (PLEASE CORRECT ME IF I AM OUT IN LEFT FIELD)
1) create plane for datum A (constructed plane from vector points)
2) create three points along the left outer edge
3) create three mirrored points along the right edge.
4) create three MID POINTS for each pair of left/right points from step 2 and 3.
5) Do the exact same thing for the top and bottom outside edges creating three more mid-points.
6) create two 2d lines constructed from the mid-points to get a "center-of-the-part" pair of intersecting 2d lines.
7) align: level to plane A, rotate to long "center" line, origin X at long "center" line, origin y at short "center" line, origin z at plane A.
Or should I be using simulated datums? or is there a way to create these datums of size (+/- .020") some other way that I am not thinking of?
Using 3.7MR3, 1mm ruby tip.
Comment