Locating scribe-lines with GDT
Locating scribe-lines with GDT
(OP)
We have a design application that requires "narrow" (scribe) radial reference lines for alignment at assembly. I have never seen an example in any literature for using GDT to control the location of lines relative to specified Datums. Because the line - like on a steel scale - has width - say .005-inch - I was considering using position. But this seems like overkill. Does anyone have any suggestions or examples I might review?





RE: Locating scribe-lines with GDT
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Locating scribe-lines with GDT
RE: Locating scribe-lines with GDT
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Locating scribe-lines with GDT
RE: Locating scribe-lines with GDT
http://files.engineering.com/getfile.aspx?folder=e...
Out of curiosity, do these scribe lines physically align parts in assembly or are they done just to mark some other features that in reality will be used for alignment (like for example marking a hole in a circular pattern of bolt holes to indicate that the marked hole should be located in assembly at 12 o'clock).
RE: Locating scribe-lines with GDT
RE: Locating scribe-lines with GDT
How's this for a practical approach? Lay out the lines in a supplemental 2D drawing using basic dimensions related to datums, then indicate that the entire (real and measurable) width of a scribed line must fall entirely within some small distance from the ideal, basic line. The result is 2D zone of acceptability. Not official GD&T, but I'd bet that lots of "things" get applied to part surfaces using a method similar to this. I have seen adhesive decals applied using a gauge with a window in it, same concept.
I admit that this method is not perfect. For example, where do these ideal lines actually exist? Are they on one of the planes of the DRF, then projected onto the imperfect part surface? How deep does the rabbit hole go?
RE: Locating scribe-lines with GDT
RE: Locating scribe-lines with GDT
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?