Reporting Datum Target Dimensions
Reporting Datum Target Dimensions
(OP)
I have a drawing with datum targets thats similar to what I have attached with 3 bolt holes inside the profile. I need to do a first article inspection on this part and I dont know how I should inspect and report these dimensions for the datum targets. I am using an Optical CMM and I just use the bolt holes as a datum alignment so I dont need to use the profile. I can use the 2 outside radii as datums but the 45 degree and Basic .212 do nothing for me. How would I go about inspecting this part with these datum targets and how would I report them? Or do I?





RE: Reporting Datum Target Dimensions
RE: Reporting Datum Target Dimensions
RE: Reporting Datum Target Dimensions
Think of a regular datum, symbolized by a triangle. When you see a triangle symbol for datum A, you don't report anything -- it's just telling you which surface to zero out on. The same thing applies here! The only difference is that with datum targets they're getting a little more picky about which portions of a surface you probe in order to establish a datum.
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems