Surface profile at MMC?
Surface profile at MMC?
(OP)
I have a project involving two irregular shapes which must fit inside each other without interference. I'm trying to figure out if I have the GDT notation correct. The attached picture should explain itself. Anyone care to offer a suggestion?
Thanks!
Thanks!





RE: Surface profile at MMC?
RE: Surface profile at MMC?
2.Profile tolerance may be combined with positional tolerancing where it is necessary to control the boundary of the feature, ASME Y14.5M standard Fig 6-19 is an excellent example on your application.
3.You need to add an "all around" symbol on bend of the leader line to specify the profile tolerance zone covers all surfaces around the outline of the feature.
4.Material modifier MMC is not allowed here, but it is allowed on datum.
5.To avoid the interference, I will recommend:
*To choose unilateral inside tolerance for male part.
*To choose unilateral outside tolerance for female part.
SeasonLee
RE: Surface profile at MMC?
You mentioned that MMC is not allowed here but is allowed on a datum?? What standard are you using? If one is using the 2009 standard, MMC is allowed on the datum if it is a feature of size or surface. Using the 94 standard, MMC is only allowed on a datum that is feature of size but not on a surface.
Dave D.
www.qmsi.ca
RE: Surface profile at MMC?
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RE: Surface profile at MMC?
Regarding the need for datum features, it depends on how the two parts go together. If the two irregular surfaces just need to mate with one another without any other features being aligned in any particular way, then datum references are not needed. This seems unlikely though.
I would guess that the two parts would need to mate together with full contact between the "bottom" face of the upper (female) part and the "top" face of the lower (male) part. In this case, the mating face on each part should be labeled as a datum feature and referenced in the Profile callout for that part.
It is also possible that certain "sides" of the two parts are used to align the parts to each other. If this is the case, the aligning sides need to be labeled as datum features and referenced in the Profile FCF's.
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca
RE: Surface profile at MMC?
RE: Surface profile at MMC?
Definitely with the 1994 standard, you can use a broken line on one side of the profile to show which way it can vary. This allows you to draw and specify at MMC or LMC. I do not see why the 2009 standard would change this.
Figure 6-18 in ASME Y14.5M-1994.
RE: Surface profile at MMC?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Surface profile at MMC?
RE: Surface profile at MMC?
RE: Surface profile at MMC?
2. The profile tolerance on your attachment means the default bilateral equal distribution condition, on your case the profile tolerance should be :
For male part: profile|.01 circle U 0 |A|B|C|
For female part: profile|.01 circle U .01 |A|B|C|
The figure 0 behind circle U means unilateral all inside tolerance while the figure .01 behind circle U means unilateral all outside tolerance
SeasonLee
RE: Surface profile at MMC?