huangyhg

is it possible to use isometric or trimetric drawing views o
is it possible to use isometric or trimetric drawing views on a pure asme 14.5m drawing package? on asme y14.3 page 5 fig 4 defines what a third angle projected view. on this illustration there is an isometric view. throughout the asme standard series there are isometric views everywhere. i would like to revisit the subject of isometric or trimetric views on drawings per the asme y14.3 standard. (
i don't know if this helps, but we have started adding a note specifying that the drawing is to be interpreted per y14.41, which refers back to 14.5 and 14.3.
this allows the use of other than orthographic projections on a drawing. per para 3.3.2(a) "a complete definition of a product shall contain a model and a drawing that may contain orthographic views, axometric views, or a combination thereof. annotation may be applied to the model, or on the drawing, or a combination thereof."
this lets us do as we wish in regard to what views to include on the drawing.
believe it if you need it or leave it if you dare.fff"> - robert hunter
asme y14.5m-1994 section 1.4
(g) dimensions should be arranged to provide required
information for optimum readability. dimensions
should be shown in true profile views and refer
to visible outlines.
i would interpret that to say that as long as the feature is shown true size and shape, you can dimension it per asme y14.5m-1994. the problem with isometric or trimetric views is that most of your features are not shown ts&s.
however, like ewh said, you can always callout asme y14.41 and then isometric dimensioning is allowed (as long as it follows the rules, many cad systems do not support y14.41 yet).
david
when i did a lot of sheet metal design, i found that placing a small isometric view on the drawing of the fully formed part was very appreciated by the guys running the press breaks. i don't recall placing dimensions on those views though.
"art without engineering is dreaming; engineering without art is calculating."
dimensions are allowed in views that are not true. however, it is my understanding that those dims much be identified as such, such as putting the word true in from of them. this is normally only applied when a radius cannot quiet be shown true in an orthographic view, but if any dimension isn't shown true, there should be come notation to that effect somewhere on the drawing.
another part of the problem with dimensioning to isometric views is that it can quickly get confusing as to which dimensions relate to each other, as features can often be dimensioned several different ways simultaneously.
matt lorono
cad engineer/ecn analyst
silicon valley, ca
we routinely show an iso view in the corner somewhere on virtually all drawings, in addition to adequate orthogonal views. it can help get an idea of what the part (or assy) generally looks like and can help interpret the orientation of other views. it's especially useful for people not as used to 2d drawing interpretation.
however if working to 14.5 not invoking 14.41 then i'd probably side with aardvarkdw on 1.4(g), wish i'd noticed it when i brought up the question originally. to me a profile view would be a true view on one 'side', not an iso or similar view.
of course it says should not must so, iso's are technically fair game unless anyone knows another reference.
as to balloons etc, it doesn't really forbid them as it talks about dimensions.
however, in an iso view it's sometimes difficult to tell exactly where things line up etc so in this case orthogonal views may still be clearer.
why don’t checkers like them, well apart from the above, which is perhaps ammunition enough, there’s the factor that many checkers probably learnt to draw on the board, or at least 2d cad. even then, my old checker said he’d used them on piping.
reluctance to use them, well the above partly covers it. my biggest thing is that the drawing must be unambiguous. sometimes iso etc views can be misleading, including on assemblies.
not explicitly in your post but as regards exploded views, my problem with these, at least as the only views, is that they don’t actually explicitly show where the items actually end up. to my understanding this contravenes asme y14.24-1999 4.1.3 (d) “depiction of the items in the assembly relationship…�br />
so in summary, even though i started out on 3d cad, i prefer the classic orthogonal views most of the time.
kenat, probably the least qualified checker you'll ever meet...
as one of those "old guys" who grew up with 3 view orthographic projections and "aux" views, i also adhere to para 1.4g, and site it as a back up for y14.3 type projections.
in my present place we do our pro/e draft files in orthographic and aux projections with one or two iso pictorials added on complicated parts for clarity, but do not dimension to them. on some assemblies, we will show that iso exploded for clarity, but it will not be the main view.
we reserve the use of asme y14.41 only for our mbd drawings/models.
the discussion is turning to dimensions of views. i would like to keep this to the following subject. can we use isometric and trimetric views on a pure amse drawing package? another way of saying it is, i am abiding by the amse standards can i use isometric and trimetric views?
dan
"can we use isometric and trimetric views on a pure asme drawing package"
yes
asme y14.41 allows this. so if you invoke it then yes.
even without invoking 14.41 you can still use them but there are some restrictions.
you asked if there were restrictions on iso views, hence all the stuff in the replies about not dimensioning to them.
i do not know of a standard which say's you can't balloon to them. however as i mentioned above in practice ortho views may often be more clear. i had an instance of this just this morning.
kenat, probably the least qualified checker you'll ever meet...
as kenat posts, yes per y14.41, with restrictions per y14.5.
believe it if you need it or leave it if you dare.fff"> - robert hunter
"can we use isometric and trimetric views on a pure amse drawing package?"
"i am abiding by the amse standards can i use isometric and trimetric views?"
what do you mean by asme (i am assuming that is what you meant to type) standards? most people on here will assume that by saying "asme standard", you mean the drafting standard asme y14.5m-1994, but asme publishes many standards. the ones that most apply to drawings are the y14 series. within this series is asme y14.4m pictorial drawing, which explicitly defines how isometric and trimetric views should be made and applied to a drawing. this standard references asme y14.5m-1994.
the answer to your question, as written,is yes.
david

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