Flatness of a derived median plane per unit length.
Flatness of a derived median plane per unit length.
(OP)
I am looking for input on how to specify flatness per unit length for longer pieces of shaft, 300+ mm in length. Pre 2009 we used straightness of a median plane and specified it per 30mm. Using the 2009 standard, we would use flatness and thus my question. Do I specify the length per inch (option 1) or as an area (option 2) & is the area intuitive? Since flatness is a measurement of area, I tend to lean towards option 2, but it seems less than intuitive. I do not see any support in Y14.5 or any other text that I currently have. Alternatively, is there another correct method that I am missing?
Drstrole
GDTP - Senior Level





RE: Flatness of a derived median plane per unit length.
Seems to me, if that is ironed out, then the same concept applies to FOS flatness.
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
http://www.gdtseminars.com
RE: Flatness of a derived median plane per unit length.
Frank
RE: Flatness of a derived median plane per unit length.
Per J-P, I see no reason that extension of principles wouldn't get you to per-unit-area on a derived median plane. As for per unit length or per unit area, it's a surface rather than a line element control, so per unit area is appropriate.
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Flatness of a derived median plane per unit length.
Frank
RE: Flatness of a derived median plane per unit length.
RE: Flatness of a derived median plane per unit length.
thanks CH
RE: Flatness of a derived median plane per unit length.
"Diameter" symbol was introduced in 1973, "square" in 1982.
What other kind of shaft can you think of?
RE: Flatness of a derived median plane per unit length.
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Flatness of a derived median plane per unit length.
RE: Flatness of a derived median plane per unit length.
Frank