ABSTRACT
I have been sitting at my work station all morning applying geometric symbology to my parts. I never thought I would say this but I am actually having a lot of fun using the symbols. It's as if they are words-only clearer-to convey the parameters within which my parts will function. Since taking your course I look at the drawings, as you like to say, "with new eyes." I see all that is there, but now I also see all that is not there. I can't believe all the assumptions I made before, assuming those reading my drawings would somehow, psychically I guess, be able to discern my needs. Now I simply take a little more time up front to tolerance. This symbology, once you have worked with it for a while, makes it easy to convey precisely on the detail drawings how the product seats and orients itself in the assembly, using the functional datum features. I can't get over how easily it can isolate different geometric needs of the feature and handle each individually. Early returns from our vendors have been excellent. I was genuinely, but pleasantly, surprised at how many do use and understand the geometric symbology. I have gotten quotes for product production based on my new drawings that are lower. That was a real shock, but the way the vendors explained it-the use of the specified datums told them exactly how to set up the parts to produce them, the use of basic dimensions got rid of tolerance accumulation, and the use of realistic tolerances that are calculated gave them confidence that the number of in-process changes would be reduced. They also said they were now able to quote us prices based not only on the original tolerances stated in the controls, but also on additional positional tolerances that could potentially be drawn from
the size limits based on the "bonus tolerancing" principle. As I said, I'm having a lot of fun and thought I would take the time to write and let you know that I agree with you . . . it is "good stuff!" Dear Jim:
My boss keeps watching me. He even has other people watching me. Sometimes I just can't take it and scream out, "Leave me alone. Stop watching me." But this just makes them watch me more. I'm pretty sure they are listening in on my phone conversations, too. We are in glass cubicles, and when I get on the phone, at least one of the others is always on the phone. Even though they move their lips, I know it's just an act to make me think they are talking to someone, when they are really just listening in on my phone conversations. It must be that they are all out to get me. I have a few weapons and I know how to use them. What should I do? Dear Writer:
Take a vacation. Dear Jim:
Ever since I started studying the ANSI Y14.5 Dimensioning and Tolerancing Standard, I can't sleep at night. I've got all these geometric shapes and symbols going around inside my head. Tolerance zones grow and shift, taking hole patterns with them, getting close to walls, almost breaking out, but then I take out a circled M and insert a circled L or S and the walls thicken up, but then draft angle occurs and leans in on my holes, and by that time I'm sitting up in bed with all the lights on trying to figure out what the heck I'm going to do. My appearance is beginning to suffer-dark circles under my eyes, weight loss. I'm starting to look as though I'm wearing my bigger brother's clothes-the pants bunching up around my waist, my belt hanging down to my knees with about a million new holes punched in it. The reason I'm writing is I can't figure out how to sketch up the hole alignment on my belt. I don't want to just launch into punching more new holes without a drawing, because the results I have gotten with this "no geometric interrelationships/no sketch" approach have been unsatisfactory. I just can't concentrate in meetings because I'm always thinking about what symbology to use in this situation. What do you think I should use? Dear Writer:
Sominex.
