huangyhg

parallel requirement on part of a surface
i have a round, flat part with a hole in the center. it kinda looks like a huge washer. datum a is the bottom surface. how can i get a parallel tolerance of .001in to datum a for theoretical area 12in in dia. from the center of the part and then the remainder of the part has a parallel tolerance of .003in? right now there is a fcf with a parallel symbol and no tolerance that references a flag note which says, "top surface to be parallel to datum -a- to within .001" inside n12.000" from center cutout and .003" across the rest of the surface."
is this alright or is there a better way. any suggestions are helpfull. let me know if you need a pic in order to visualize this.
david
how about adding a phantom line circle 12" in dia centered in the part center and then applying cross hatch to that area. you could then have feature frame labelled 'hatched area' or 'shaded area' or what ever terminology you use, with the .001 requirement.
you could then have a separate feature frame for the rest of the surface. not sure if you'd need to label it 'except shaded area' or something.
if it's a fairly busy drawing though the shading may not work well.
just an idea for you to play with and everyone else to pick apart.
while the note is probably adequate a picture paints a thousand words as they say.
that is essentially what i was thinking as well. one stupid question though, would you attach the fcf to the shaded area with a leader and a dot instead of an arrowhead? i have only found examples in the asme y14.5 standard that show fcf's attached to the profile of a surface.
maybe something like this?

chris
systems analyst, i.s.
solidworks 06 4.1/pdmworks 06
autocad 06
chris,
exactly. your example works for me, anyone want to dispute it?
you can't find a sharper pencil on this forum than chris
but i will add that we often use a phantom line instead of a centerline to define the 12.00 dia circle.
cheers
i don't know anything but the people that do.
thanks.
true, i would use a phantom line. i was just trying to show an example. wasn't thinking about the line type.
nice catch!
chris
systems analyst, i.s.
solidworks 06 4.1/pdmworks 06
autocad 06
aardvard,
i think a chain line might be appropriate for designating the 12 in dia.
close, chris, but no cigar. by putting the parallelism control with the dimension, you are indicating a parallelism control for the axis of the dia-12in circle (asme y14.5m-1994 fig. 6-31, 6-32, 6-33). also, controls are to be shown on the edge-view of the surface.
jim,
i understand. you are correct. i also thought of showing at edgeview of the surface, but wanted to just show a quick reference to indicate what david (aardvarkdw) was trying to explain.
i didn't have asme y14.5m-1994 at work to look up details.
nice link. i will bookmark.
i don't smoke anyway.
chris
systems analyst, i.s.
solidworks 06 4.1/pdmworks 06
autocad 06
thanks jim. would i want to put a "seperate requirements" note on the fcf's so that they arn't applied together?

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