Dumb GD&T Question

[Farmer]

EXAMPLE.JPGHi, Im here to ask my (now) daily dumbass GD&T question. I really have no idea what the GD&T in the cyan box is asking of me (See Att.)? Whenever I see a basic angle dim I rotate my co-ordinate system by that amount but the 15.50 dim is not perpendicular to this angle (like it should be) & there are no other co-ordinates for the Radii. Datum D is the face that the radial slots are on so obviously I check the perpendiculaity of these features to this face (True pos Ø 0.30 D) but apart from that Im stuck.
Any ideas/theories would be warmly welcomed.


Cheers



F

[Matthew D. Hoedeman]

I would measure the end as a 1/2 circle, then report the center point of the circle.

[kbotta]

There are no dumb GD&T questions. Never.
kb

[Matthew D. Hoedeman]

Er, what do GD&T stand for?
Gertrude, Dennis and Toni?
Sorry, just trying to lighten the load today.

[\v/inston]

Er, what do GD&T stand for?
Gertrude, Dennis and Toni?
Sorry, just trying to lighten the load today.

admin please move to the corniest joke thread.

[Wes Cisco]

Er, what do GD&T stand for?
Gertrude, Dennis and Toni?
Sorry, just trying to lighten the load today.

I was presented a resume the other day. We are looking for a nightshift operator/programmer. This came thru an employment agency and seems to have been taylored to what we said we were looking for. The resume states the person uses trigonometry daily and has Co-ordinate measuring machine experience. But no where does it say what type of CMM or software. In one place it reads "GDNT" and in another location "S.D. & T, (Geometric Dimesioning & Tolerancing)". On top of that the person claims to have two bachelors and a masters degree! I called BS. The agency is verifing the education and if that checks out, I guess I will be doing a phone interview. I think I might start with, "How would you define the phrase 'attention to detail'?"


Sorry to hijack your thread. I agree with Kevin, there are no dumb questions, even when you realize you know the answer seconds after you post, you had to post to get your answer! I think you have landed on of the engineers I normally get. I looked at your attachment and I would have to pose a series of questions about how to interpret that nonsense. There could be more information in areas not posted that clarify; but I could not see why the dimension from the square end of the slot to the radius center was not basic, for just one example of what made me think the engineer just thinks GD&T looks cool but has no idea what it really does. I see it all the time. I sometimes wonder who understands it less, the machinist or the engineers?

[bboyd]

I think you have landed on of the engineers I normally get. I looked at your attachment and I would have to pose a series of questions about how to interpret that nonsense. There could be more information in areas not posted that clarify; but I could not see why the dimension from the square end of the slot to the radius center was not basic, for just one example of what made me think the engineer just thinks GD&T looks cool but has no idea what it really does. I see it all the time. I sometimes wonder who understands it less, the machinist or the engineers?

This kind of stuff is why we have job security.

[kbotta]

Not to mention that the pltzf and frtzf are backwards he he he, oopps!
Needs to be checked be a checker.
kev

[William Johnson]

What is datum -c- and where is the basic dimension from datum -b- at ?
I would tolerance this in 2 ways. The first would be t.p. from datums -a- and -b- if you can some how back figure what the basic is from -b-. Then i would measure 2 lines and construct a mid line between those 2 lines. Then tolerance the polar angle of the mid line. As I don't know the design or intent here this is just my .02 worth.

[#2#]

I sometimes wonder who understands it less, the machinist or the engineers?

Amen brother! If you think about it we are the only ones who have to understand the GD&T. The engineer just puts it on there as a tolerance and if it isn't quite correct who cares. The machinist just makes it as close to nominal as possible.

I took a GD&T class a couple of years ago. When I got back I actually had the confidence to challenge some of the engineers on what they had called out. One of them later asked me about the class and if I thought it was helpful. I don't think he ever went to the class though.

[John Kingston]

I was presented a resume the other day. We are looking for a nightshift operator/programmer. This came thru an employment agency and seems to have been taylored to what we said we were looking for. The resume states the person uses trigonometry daily and has Co-ordinate measuring machine experience. But no where does it say what type of CMM or software. In one place it reads "GDNT" and in another location "S.D. & T, (Geometric Dimesioning & Tolerancing)". On top of that the person claims to have two bachelors and a masters degree! I called BS. The agency is verifing the education and if that checks out, I guess I will be doing a phone interview. I think I might start with, "How would you define the phrase 'attention to detail'?"

So when are you calling me for my interview?

I agree, the only dumb question is the one you didn't ask.

[Farmer]

Thanks guys. I posted this because I need to get my programs finished quickly before I jet off on vacation. The Engineer I needed to speak with wasnt available. Fortunately I spoke with the design manager who agrees that its not dimensioned correctly. They are currently revising the G,D & T ;o)
Expect me to ask you jedi masters what the heck rev C means ;o)

Best



F

P.S. I agree, there is no such thing as a stupid question, I do feel kinda bad bugging you guys all the time though.

[Wes Cisco]

P.S. I agree, there is no such thing as a stupid question, I do feel kinda bad bugging you guys all the time though.

Don't feel bad for bugging us. We are happy to help. That is why we do it for free. If you want to feel bad about something: try calling tech support with your next question and then compare the speed and accuracy of their response to what you have seen here on the forum, now factor in the amount of SMA you pay vs the cost of your internet connection. That will give you something to really feel bad about!

[Mike Johnston]

Once upon a time we hired a guy who claimed to know everything there is to know about.... get this.... "geographical dimensioning and tolerancing".

What a wiz.....

[kbotta]

And you hired him???