Good morning,
I have a quick question regarding how to align to a part. Datum A is the OD, Datum B is the slot, and Datum C is the end of the part. I am not sure about rotation on this one because I don't have enough surface area to take planes on the slot. How accurate would it be to:
1. Measure a point on each side of the slot (same Y value for each point)
2. Create a line between the OD center point and the midpoint of those 2 points
3. Rotate to that line
Any other ideas?
That would probably work, it seems fine. I was trained to be sure my alignment used actual hit data for each X, Y, and Z depending on which I am rotating to. So in this case your Z data is all you have (assuming Y workplane, and tab is on right side of part). I would also take a third hit in X relative to the Z of that midpoint created by those first 2 hits so that I have X data.
I made a very crude drawing in paint. Assuming slot is on the right of the part. Viewing in Y workplane.
Sorry William, can you please explain a bit more? I'm honestly lost.
Here is a picture of my part. Sorry, I meant to include this picture in my original post. So far, my plan is to physically clock to the slot as best as I can on the CMM grid plate.
Obviously, I will level to the OD of the part. After that, I'm not sure how to go about this..!
Usually with something like this, I try to measure a couple features and construct intersection points, like this:
Then, I would construct a midpoint of the 2 intersection points.
However, in this case, I don't think I can construct those 2 intersection points...
I am not entirely sure what I am looking at, but based on your second picture. Are you able to make a line at at each side of the slot at the same depth your origin circle is measured, and do a pierce/intersect point where that line pierces or intersects the circle?
William, that's exactly what I was thinking. That's what I was referring to with this picture. I tried it, and the pierce point comes out on the other side of the part 
Even if I try reversing the line. Maybe it would work regardless of where it is piercing, but it's a bit concerning. Any other ideas? I wish it was possible to intersect a plane and a cylinder OD to create an intersection line...
William Johnson, another poster, just recommended lines on each side of the slot, a midline, and rotating to that midline. I could do that, but I am concerned about accuracy. This slot is pretty short.
