14.5m-1982 vs 14.m-1994
14.5m-1982 vs 14.m-1994
(OP)
Hey guys,
I'm trying to get a list of about 4-5 big changes that you would see between the old ansi y14.5m 1982 and the asme y14.5m 1994. I know it's probably dependent on the drawing but i'm just looking for the big obvious changes.
Thanks,
Pete
I'm trying to get a list of about 4-5 big changes that you would see between the old ansi y14.5m 1982 and the asme y14.5m 1994. I know it's probably dependent on the drawing but i'm just looking for the big obvious changes.
Thanks,
Pete





RE: 14.5m-1982 vs 14.m-1994
When the people fear their government, there is tyranny; when the government fears the people, there is liberty. - Thomas Jefferson
RE: 14.5m-1982 vs 14.m-1994
KENAT, probably the least qualified checker you'll ever meet...
RE: 14.5m-1982 vs 14.m-1994
The changes that jump out at you are:
1. Using the dumb looking ISO plunger datum symbol vs the letter within dashes.
2. Not using the circle S (RFS)symbol in the FCF, since RFS is the default with 1994.
3. Controlled root radius (CR) is now what R used to be in 1982. (Need to read section 2.15 in 1994 spec)
RE: 14.5m-1982 vs 14.m-1994
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: 14.5m-1982 vs 14.m-1994
As to frustration about SR, I see your annoyance and raise it 10 fold
KENAT, probably the least qualified checker you'll ever meet...
RE: 14.5m-1982 vs 14.m-1994
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RE: 14.5m-1982 vs 14.m-1994
Also, please note that ASME currently has a new version of ASME Y14.5M in the works right now. It may be released this year, but don't hold your breath. I'm guessing the standard will eventually be ASME Y14.5M-2009.
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: 14.5m-1982 vs 14.m-1994
A bit off topic to the OP but since it was commnted on:
One has to be careful with the use of CR.
One of our programs added a standard drawing note that "All radii be CR unless otherwise specified."
The intention was to inspect CR's the same as the old R's were under the 1982 spec (for tangential radii only).
Inspection went hog wild, however, and started inspecting all of them with magnification and cast molds, looking for flat spots, radii reversals and tangental mismatch, and writing a lot of rejections.
Obviously, the note was too broad, and we since have restricted CR usage to highly stressed and fatigue critical areas which are identified by stress analysis (or analysts).
RE: 14.5m-1982 vs 14.m-1994
The bottom of a blind ball end milled hole would be an SR
(not SR FULL), and an internal spherical feature >180° i.e. the reverse of Fig 5-62 would be an SØ.
AGREE??
RE: 14.5m-1982 vs 14.m-1994
RE: 14.5m-1982 vs 14.m-1994
KENAT, probably the least qualified checker you'll ever meet...
RE: 14.5m-1982 vs 14.m-1994
RE: 14.5m-1982 vs 14.m-1994
RE: 14.5m-1982 vs 14.m-1994
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: 14.5m-1982 vs 14.m-1994
The reason that change is so significant is because print dimensioning gets copied from older designs to newer ones! For instance...a composite position control on a dowel pattern that formerly provided rough control for rotation of the pattern relative to an engine's crankshaft bores (primary), bearing thrust face (secondary), and oil pan face (tertiary) in the upper segment...then refined location of the pattern to the crankshaft bores in the lower segment... if copied... would not refine location in the lower segment according to the 94' definition of a composite FCF.
To control the dowels equivalently with the 94' standard in this case one would have to use two single segment position controls rather than copying the former composite FCF.
Have mistakes like this been made? Absolutely!
Unfortunately stack layouts get copied too so the problem never surfaces in design... but fortunately process tooling and gages get copied so the problem goes unnoticed. The only time a big problem occurs is when someone who knows how to interpret the composite callout but has no history with the intended control...designs a new process, codes a new CMM program, or builds a new gage and lets the pattern drift within the larger upper segment zone.
Paul.
Paul
Paul
RE: 14.5m-1982 vs 14.m-1994
non-circular position and profile-of-a-surface tolerances could better control symmetry.
What was brought back in 1994 in section 5.14 and Figure 5-61.
I personally find no use for it, since it treats the surface width as a composite of several elemental point measurements within the tolerance zone and does not treat the total surface as profile of a surface or position does, thus it could conceivably buy off a very jagged, rough slot, like a bad keyslot.
I guess some on the ASME Y14.5 committee envisioned applications for it, but I sure haven't found any.
Same is true for Concentricity. Runout, or position is so much better.
RE: 14.5m-1982 vs 14.m-1994
RE: 14.5m-1982 vs 14.m-1994
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: 14.5m-1982 vs 14.m-1994
Since I'm not a GDT trainer, I giving the shortest answer I can.
As far as what symmetry and concentricity is today, read your 1994 y14.5.
Symmetry in the 1973 Y14.5 was defined exactly the same as Position of non-circular features RFS-RFS is in the 1994 spec. Take Fig 5-60 of 1994 Y14.5 and substitute the symmetry symbol for the position symbol, and that's what it was.
The 1973 standard even recommended that you use position instead, because that would allow usage of MMC (symmetry was RFS only).
That is why is was dropped in 1982, because Position could do the same thing and utilize both RFS and MMC.
Concentricity started out as being inspected just like runout--surface to surface. Then runout appeared in 1982 for surfaces, and concentricity became coaxiality control of axes of coincident surfaces of revolution (RFS only).
It wasn't defined very well, and what's in the 1994 ed. is better.
There are still engineering people I run into that want to use concentricity for coaxial surfaces instead of Position or Runout.
Best I can explain in a short notice.
RE: 14.5m-1982 vs 14.m-1994
I think the real problem is that they change the purpose of the symbols when creating new ones, when they should prolly create the new symbols with the purpose they changed the old symbols too. I hope they don't do that any more with the new one.
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: 14.5m-1982 vs 14.m-1994
I too hope the next standard doesn't change the existing symbols. I understand there are some new ones coming.
As I said, I find symmetry and concentricity virtually useless, and the word is don't use them for surface to surface control.
RE: 14.5m-1982 vs 14.m-1994
Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 06/08
ctopher's home (updated Jul 13, 2008)
RE: 14.5m-1982 vs 14.m-1994
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: 14.5m-1982 vs 14.m-1994
But then we have WhitmireGT for a historian. I think he remembers what came before MIL-STD-8 Rev.NC
RE: 14.5m-1982 vs 14.m-1994
Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 06/08
ctopher's home (updated Jul 13, 2008)
RE: 14.5m-1982 vs 14.m-1994
KENAT, probably the least qualified checker you'll ever meet...