![asme y14.5-2009 flatness asme y14.5-2009 flatness](https://images.slideplayer.com/7/1716983/slides/slide_51.jpg)
After 12 years of research and development, Vango introduced their innovative, inflatable AirBeam tents in 2011 and soon started to develop their designs for use in other product ranges such as their campervan, motor-home and caravan awnings.
#ASME Y14.5 2009 FLATNESS UPDATE#
When there is a profile tolerance, it's simply becomes more obvious that we are not checking the tolerance exactly per the print ) That said, a caliper may be a satisfactory check whether it's a linear dimension or a profile (depending on what we know about the part, whether it's just an in-process check, etc).Since Vango's establishment in 1966, the company has grown to be one of the UK's market leaders in the Outdoor & Leisure industry and continue to design, manufacture and update their innovative outdoor equipment. But, even with linear dimensioning, we are often not actually checking the part "per the print" when we use a caliper. When we have a print with linear tolerancing, we are simply more comfortable with inspecting with basic methods.
![asme y14.5-2009 flatness asme y14.5-2009 flatness](https://i.ytimg.com/vi/AYZO3bJbktA/maxresdefault.jpg)
For example, it's understandable that when a designer applies a profile tolerance instead of a linear tolerance that I think "now I need a CMM instead of a caliper". One common misconception is that the way that the design drawing is made determines how the part must be inspected. But, for GD&T to add clarity, it is essential for there to be a proper understanding of GD&T by all involved. The goal, of course, is to give clarity to the functional requirements. I can understand the frustration of prints being over-complicated. Hi Roger Weidman Rotorion, thanks for taking the time to read and comment. The main difference with this example is that the flatness is not linked to the feature of size and therefore can't leverage potential bonus tolerance. There is another method that will control the feature in a similar (though not identical) way that may be less costly for inspection (see graphic below). I offer this to make the point that there is often more than one way to control the desired functionality of a part, but they don’t all have the same cost-factor for manufacturing/quality. The more a designer understands current manufacturing/inspection methods and capabilities, the more cost-effective the design can be (while still clearly controlling the function of the part, which is the primary goal of GD&T). One last thought for designers that may need to control a feature of size in a similar manner. Much more could be said about measurement methods (and measurement uncertainty, etc), but hopefully this gives enough guidance to show how it can be measured. If all thickness measurements are within the size limits and the flatness of the median plane is within the allowable flatness tolerance, it is a conforming part. Such as the example shown here (form deviation is exaggerated to convey concept) –ĭepending on the software, you may be able to create a formula with a variable to calculate the flatness tolerance automatically. 311” (MMC + Geometric Tolerance). So, there is a functional purpose for this callout. As an example, it may be acceptable that the part is bowed as shown below as long as the localized thickness is controlled more tightly. 301” apart. But, when the flatness at MMC geometric tolerance is added to the size tolerance, it removes the Rule #1 requirement. Which means that the only thing the size tolerance is controlling is the “local” size (localized thickness). The flatness callout then is controlling the overall form of the width (bow, etc). This also results in a Virtual Condition Boundary that cannot be violated based the accumulation of size and form variation. In our example, the virtual condition boundary would be. Though often overlooked, a size tolerance also controls form (per Rule #1). In our example, the size tolerance would require that the entirety of the feature fit within two parallel planes that are. Simply stated, this callout can be used when the local size (thickness) needs to be controlled more tightly than the overall form. Possibly plates that will be stacked or shims which will be flattened when assembled, etc. So, if the callout is valid, then we need to address the two questions at the beginning of this article, namely why and how. 5.4.2.1). The flatness tolerance in this case is controlling the form of the derived median plane. (This same concept can also be applied to a cylindrical feature of size with a straightness callout.) In this case, because the flatness is being applied to a Feature of Size (a width), it is indeed a valid callout based on ASME Y14.5-2009 (para.