Unused portion of profile tolerance zone

[Belanger]

Another thing I noticed in the 2018 standard is the graphic on page 264. On this forum we've discussed how having a profile tolerance reference a datum derived from the same surface might make some of the tolerance zone unusable (because the datum plane is created from high-point contact).
But I'm pretty sure they goofed on that picture: It says "Shaded areas show unusable portion of the tolerance zone" -- yet the entire zone is shaded.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[greenimi]

J-P,

I guess if you look on the released for public draft(11/24/2015), figure 11-21 (Rev C, 2015-07-19) the shaded areas show un-usable portions of the tolerance zones correctly.
Just some area (on the front view and on the side view) are shaded and not the entire zone.

 

[chez311]

Actually something I've noticed on some of the figures on the pdf version is that the shading changes with the level of zoom. Something to do with how the electronic copy is formatted I guess. Up to a certain point the entire area is shaded, further zoom none of the area is shaded. Perhaps it looks right on the actual print version?

 

[3DDave]

That's an odd outcome in the PDF. Originally PDF was a way to remove all control statements from PostScript files by saving the interpreted command results, so 0 1000 1 for{draw something} (I think that's close to the syntax) would replace the 1000 times through the loop with just what got drawn, unrolling the loop. But since then Adobe got clever and allowed for Javascript to be embedded and since then who knows what is possible.

Notice though they go out of their way to show multiple contacts with the third datum plane. I also don't see the point of making the zones so tiny in the diagrams.

Do they at least show the alternate of having the tolerance zone offset so that the contact is to the MMB?

 

[Belanger]

It's exactly the same in the PDF and the print version.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[chez311]

3DDave,

Do you mean the (b) case below? No - there are no figures for this case that I can tell.

11.4.3.1 When the Toleranced Feature Is a Nonsize Datum Feature.
At the datum feature, the distance to the true profile is zero. Since the datum feature may not pass through the datum plane, the tolerance on the considered feature shall be as follows:
(a) For an equal bilateral profile tolerance, half of the profile tolerance is available for variation of the datum feature. See Figure 11-21.
(b) For a unilateral profile tolerance, the tolerance may only be applied into the material of the feature.

 

[3DDave]

Sure. Why show a problem and then bother to show a solution?

 

[SeasonLee]

I guess if you look on the released for public draft(11/24/2015), figure 11-21 (Rev C, 2015-07-19) the shaded areas show un-usable portions of the tolerance zones correctly.

Would you please post the correct figure of fig. 11-21, I can't see the half shaded tolerance zoom no matter how I zoom it. Thanks

Season

 

[greenimi]

SeasonLee,
Here you are.
Shaded areas show un-useable portion of the tolerance zone.

 

[SeasonLee]

Thanks greenimi, My pdf version is fully shaded on all tolerance zone.

Season

 

[Belanger]

And my print version (received two months ago) also has a fully shaded tolerance zone. There must be different printings out there.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[3DDave]

There is a setting for Adobe Acrobat Reader to always show marks, even though they are much smaller than pixels.

It's under Preferences, Page Display, Enhance thin lines.

If the stippling is of very narrow width lines, then that could be the reason they play now-you-see, now-you-don't, and differently for different people, depending on what their version of software/setting they use.

 

[Belanger]

3DDave -- I was referring to the print book -- that's what is so strange.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[chez311]

SeasonLee/all,

Take a look at my (17 Feb 20 13:28) post. Unless your pdf version is radically different than mine the shading actually goes from fully shaded to empty/unshaded depending on your level of zoom. Ie: zoom in real close and the shading disappears entirely. Looks like there was a formatting error during the final release and it never got caught.

Actually now that I've dived deeper into it, looks like this issue is prevalent throughout the 2018 standard. The formatting is messed up at close zoom and the shading disappears entirely on many of the figures. This was not present on the 2009 standard as far as I can tell. I'm actually very surprised that nobody on the committee caught this. See attached for a full comparison of different zoom levels, and below for a quick snapshot of the level at which the shading disappears in 2018. Note I tried to quickly scale the two so they started at approximately the same size at the lowest level of zoom (why theres a 5% discrepancy) but I was too lazy to continue this through the different levels, I just went by 10% increments. I did though on the final level of zoom.

Take a look at the last slide too - notice also the loss of detail on high levels of zoom, the 2018 has much bolder lines which tend to muddy exactly what is being shown or indicated by leader lines. The figures have much finer detail in 2009. Disappointing.

 

[chez311]

3DDave,

I messed around with the page display settings, including "Enhance thin lines" which was already checked when I made those snapshots and none seemed to make an appreciable improvement in the issues that 2018 shows. Some did reduce the quality of the image though like the smoothing options.

Does your pdf document look different than what I am showing?

 

[3DDave]

I have no copy of the 2018 version, so cannot compare.

The committee likely didn't see the effect because the committee doesn't do the final compositing and layout. OTOH the publishing group doesn't generate the artwork so it's not clear who would be responsible for this. You can look at the properties to see what application generated the PDF, but that won't tell what generated the source artwork.

 

[SeasonLee]

chez311
I can see all figures' shaded area on my 2009 version no matter the percentage of zooming, so I don't have your problem as shown on the attached. But on my 2018 version, I can see all shaded area except only at 125%, 150% zooming. As for the fig.11-21, even I can see the shaded area but it fill on all tolerance zone.

3DDave
It seems no changes on the pdf display per your setting recommendation.

Season

 

[3DDave]

Season,

That's unfortunate. This is the same group that printed a basically redacted version for public comment of the 14.5.1 draft because they don't understand how running half-tone through a copier works. And didn't care enough to fix it.

Maybe comparing all the document settings would show a culprit, but it's an ASME problem and they should have had some quality control to catch it and should issue repaired versions for free. Maybe cut back on what they spend on Park Avenue coffee to pay for reprinting.

 

[chez311]

I can see all figures' shaded area on my 2009 version no matter the percentage of zooming, so I don't have your problem as shown on the attached.

So can I - the issue isn't with the 2009 version. Those shaded regions display fine for me as you can see. The issue is with 2018, I just provided 2009 for comparison.

But on my 2018 version, I can see all shaded area except only at 125%, 150% zooming.

Strange, I checked it on Adobe Reader XI (11) and DC, same issue at the same level of zoom. What version of Adobe are you using?

 

[chez311]

3DDave,

Seems like there was a ball dropped somewhere along the line. One would think there would be a final review prior to publishing. And even if the shading issue were fixed the actual level of detail on the 2018 figures is notably reduced, despite specifically putting in the effort to make them larger (and thus greatly increased the page count). Add to that my gripe of putting all the figures at the end of every section. Flipping between the text and figures has been annoying to say the least.

You're giving me PTSD about the Y14.5.1 draft watermark - I get more and more frustrated every time I look at that draft trying to decipher whats behind the blacked out portions. I'm constantly reminded of that scene from Talladega Nights with the Fig Newtons sticker...