On top of the fact that the composite FCFs are not correct, there's absolutely no reason to have the CF symbol since you have a .007 in the lower tier of the FCF.
This figure is a known typo. Of course the ENTIRE tolerance zone can't be unusable. This is a frustrating thing. It's not the only figure in error either.
This reminds me of a time when I had done a drawing for a casting and sent it to the foundry. This was around the 2012 timeframe. I used angularity instead or perpendicularity simply because I knew it was an alternative practice and I could. A couple of days later I get an email from the foundry...
Why don't you go through the process of polishing the material with 2500 grit, measure the surface texture, then use that value? What parameter are you going to specify?
John Acosta, GDTP Senior Level
Dave,
If the slot is parallel to a primary then it needs to be located from it, which means position would be the appropriate control. Maybe there's an instance where parallelism would be appropriate. Can you describe a scenario like that?
John Acosta, GDTP Senior Level
You would certainly want to control the position, unless you are controlling position with respect to a different datum. If you only control orientation, then that's ALL you are controlling. There is no implied location with an orientation control.
John Acosta, GDTP Senior Level
Based on this drawing, cylindricity is the appropriate callout for datum feature A. As Dave said, runout requires a datum reference and the total runout has no datum reference. To make things worse, you have a concentricity callout. What do you think the difference is between concentricity and...
But it doesn't have that note, nor did the original drawing, so the answer is still "NOTHING". Why even go down this road of trying to find something wrong with the lesson being conveyed?
First of all A could never constrain translation along x and B could never constrain translation along z...
Here's a snip from the Tec-ease course. This was an actual argument I had with an inspector back around 2006 or so. He insisted that datum feature reference was implied if datum features were identified, even if they weren't in the datum reference frame. This is actually what the part looked...
Simultaneous requirements does not mean that features have to be measured simultaneously, it means the features have to meet their requirement simultaneously. So you have to find the sweet spot where all the features are in tolerance simultaneously. You can't shift the part in one direction to...
The first fundamental rule in ASME Y14.5-2018 states that each feature shall be toleranced. The word shall in that version of the standard establishes a requirement.
John Acosta, GDTP Senior Level
When stubborn engineers say that they don't know what the word "Shall" means and imply that it could be an option, things get ridiculous. Most of us know that when a note says that a part "Shall be anodized" or "shall be powder coated" no one thinks twice about it. When the standard states that...
If you're saying that the projected tolerance zone extends the length of the tolerance zone by the length of the chain line then no, it doesn't do that. The projected tolerance zone moves the zone from inside the feature to outside. The zone is no longer inside the feature.
John Acosta, GDTP...
Oh Jeez! There where it says "leading zeroes", mine is set to "show" thus ignoring the requirements of the standard. Thanks Chris.
John Acosta, GDTP Senior Level
