Hmmmmmmmm - - - - I understand that G D & T isn't much used but then there also seems to be this HUGE divide between those on the shop floor and those sitting in the engineering office. Experience has shown that quite often any flaws in fabrication are leveled at the shop floor - - - yet the engineering office didn't seem to want to take time to specify what they did what - - - - and why. The second part is very important. If some 'feature' is listed as being removed in the future, say something used to assist in assembly, without specifications (which should be included in the G D & T) - - - - well a mess results.akredd wrote: ↑Fri Apr 03, 2020 4:46 pmHello,ajoeiam wrote: ↑Thu Apr 02, 2020 9:21 pm ...
Was introduced to it in my apprenticeship and didn't see that much use in industry but find that the concepts are very much useful.
Its not just tolerances - - - - those are easy and if all you've got is a pin in a hole that's sort of straight forward.
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that's the point - it is not much used in industry yet. But ISO 1101 (Tolerances of form, orientation, location and run-out (ISO 1101:2012 + Cor. 1:2013)) and ISO 25178-1 (Surface texture: Areal – Part 1: Indication of surface texture (ISO 25178-1:2016)) are changed to be used in 3D. So some additional labels are created for direction (in a drawing it is mostly in direction of the plain paper) e.g. All this is documented in ISO 16792 (Technical product documentation - Digital product definition data practices) as used by juanvanyo. The problem is, I can have a look at ISO 1101 and 25178, but not on ISO 16792. And I know that it is not allowed by law in Germany to share ISO's. You have to buy them at Beuth-Verlag.
I think it would be very useful to have a 3D-representation of GD&T and to have it in the STEP-export. Only than it makes sense. In my dayly work at Creo I see, that some of that features works good there, but they are not easy to create (in the sense of a machining engineer).
I will try to work with GD&T next time to give some feedback here, because I have a bit of time now. Our factory is closed a while due to crisis and corona.
Stay helthy
Andreas
Have also found that tolerances that are just taken sorta blindly from engineering specifications often result in parts that don't work in real life. There is this crazy balancing act between tolerances that are useful and fit the intended use function and the abstract concepts in designing something.
I'm not sure how burying very useful specifications inside extremely expensive documents actually helps industry - - - imo it just makes standards publishers rich. Not sure what even to ask for so that it is possible to create models that are useful tools in the production of artifacts. Just doing things has far too high a likelihood of heading in a direction that doesn't fit the standards yet not having reasonable access to the standards does exactly that.
Maybe its time for some standards to be open sourced? (Likely not going to happen but without asking for it it never will happen!)
Please don't stone me, I work in the engineering office for 38 years now... and that is practice. But that is not the target of GD&T-WB, that is only the responsibility of the engineer. GD&T-WB should give the possibility to mark some elements of the construction with tolerances.
