http://gdtseminars.com/blog Geometric Dimensioning & Tolerancing tips, questions and issues Mon, 26 Dec 2011 16:54:07 +0000 http://backend.userland.com/rss092 en If you've been keeping track of the new GD&T standard, then you're probably aware of most of the bigger changes. (Yes, I know that 2009 doesn't sound "new," but most people still call it the new standard since it takes a while for companies to switch to a new dimensioning ... http://gdtseminars.com/blog/2011/12/21/another-new-symbol-in-gdt/ I hope everyone has had a great summer.   Here's a topic that will be helpful even to seasoned experts in GD&T, and it kind of follows the previous blog entry...Often, when discussing the finer points of GD&T with others, we end up going to the official standard (or standards) ... http://gdtseminars.com/blog/2011/08/30/how-literally-should-we-take-the-gdt-standard/ Sorry that it's been a while since my last blog post!  That simply means that our training schedule has been busy.  Though a good portion of the U.S. economy is still sluggish, I have definitely seen an uptick in the number of requests for GD&T training.  So remember, if you ... http://gdtseminars.com/blog/2011/03/30/is-there-always-a-right-vs-wrong-way-in-gdt/ This website and blog naturally focus on GD&T, but it's a good time to discuss the importance of simple print-reading skills as a prerequisite to learning GD&T.  As I travel around teaching classes on GD&T, you'd be surprised how many people don't fully understand some of the simple rules of ... http://gdtseminars.com/blog/2011/01/05/the-importance-of-blueprint-reading/ Several months ago I wrote about the requirements for becoming certified as a "GD&T Professional."   (View that blog entry here.)    This time, I would like to present some advanced questions.There are two levels of certification for GD&T Professionals: Technologist and Senior. You do not need to be certified at ... http://gdtseminars.com/blog/2010/09/06/sample-senior-level-questions-for-asme-certification-in-gdt/ In my opinion, one of the most underutilized tools in the GD&T toolbox is the tangent plane modifier. It was introduced in the 1994 ASME standard, yet some people still think of it as a new concept.  Shown in the example below, the tangent plane modifier (circled T) can save ... http://gdtseminars.com/blog/2010/08/20/tangent-plane-modifier/ This time around, I'd like to present another "pet peeve" of mine, at least in the world of GD&T.  It involves using the position symbol when the only quality being controlled is perpendicularity.This is very common -- it stems from some subconscious notion that if GD&T is going to be ... http://gdtseminars.com/blog/2010/05/18/position-with-only-one-datum/ Occasionally users of GD&T suggest that everything be simplified by just boiling all 14 symbols down to just two or three.  (What, you didn't know there were 14 symbols? Click here for a handy chart!)There is some logic to what these people are saying -- namely, that many GD&T symbols overlap others, ... http://gdtseminars.com/blog/2010/03/02/position-and-profile-for-everything/ Another new feature that was introduced in the 2009 standard (ASME Y14.5-2009) is the option of creating a "non-uniform" tolerance zone for either of the two profile symbols.Recall that the profile symbols normally specify a uniform boundary or bandwidth that is centered around the "true" or perfect profile. This true ... http://gdtseminars.com/blog/2010/02/08/non-uniform-profile-tolerancing/ I wrote about this a long time ago, but it's worth mentioning again as the new year approaches (for people who still do New Year's resolutions!).  Regular GD&T users should be aware of the certification process for GD&T Professionals.The American Society of Mechanical Engineers (ASME) has established a credential ... http://gdtseminars.com/blog/2009/12/18/becoming-certified-in-gdt/