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what is bottom up & top down assembly

When designing you have to have basic design of the component you want to model (e.g. sillhouettes). You can then model all the components and assemble them in the assembly (that's bottom-up approach) or create design sketch in the top level assembly, create components in that assembly which do not have any geometry, copy design sketch geometry to thosecomponentsand drive all of the components geometry with that sketch. That's top-down approach.
 
skraba said:
When designing you have to have basic design of the component you want to model (e.g. sillhouettes). You can then model all the components and assemble them in the assembly (that's bottom-up approach) or create design sketch in the top level assembly, create components in that assembly which do not have any geometry, copy design sketch geometry to thosecomponentsand drive all of the components geometry with that sketch. That's top-down approach.
Click to expand...
 
Hi,


Its right. Moreover particularly used with skeleton modeling, Where u can even make ur models with perfect fitness(when the parts as to be designed with reference to the assembly)


With regards,


Mani
 
Hello fellow Pro/E users


Top down design is perfect for Indusrtrial Designers, it allows us to spit out many different concepts from one basic deisgn. Just like sketching on paper during ideationprocess.
 
Imagine a component that you can only design in a finished assembly (the "top").


Examples are:


Running wires and cables from part-to-part


Piping & tubing


Welds


A "third" component to fit between 2 or more components.


These are the principal examples of "Top Down" design.


"Bottom Up" design is simply design of parts that don't have to be designed in an assemblage of parts.
 
to nmpatel





tutorials are available in net just run google, for sure this subject is well discussed in this forum. I know thatbecause I learned from this source


what I can say about top down design - it is good way to model prototypes, new devices, but I would walk this funcionality a mile around if You are considering using it to model existing assembly from 2d documentation.


Top down design creates a lot of external references and while You use system likePro\Intralink or PDMLINK You might have a problem with ghost in the future





so beware
 
nmpatel,<?:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><O:p></O:p>


PTC has a 115 page pdf named "Top-Down Design Task Guide" on their web site available for downloading (probably requiring maintenance contract to access, I've had mine a while).<O:p>


Also for those inquiring people who try and stay in the loop, there is a relatively new concept out named "horizontal modeling". Too elaborate to discuse so for information just do a search on the internet on "horizontal modeling".</O:p>
<O:p></O:p>



Edited by: ncprog
 
"Delphi Corp., has just unveiled a new technique called horizontally structured modelling (patent applied for), which promises significant flexibility and cost savings for users of 3D Computer Aided Design ( CAD ) and Computer Aided Manufacturing (CAM ) systems."


Isn't Delphi in bankruptcy???


Anyone have any real information on what "horizontal modelling" actually is ???
 
With that article arises the question about associativity and parametrical models. How can this be done, when all features are independent of each other? If they aren't (if they are dependent through some other feature - like sketch), then there's a questions of more features involved in the model than needed (memory usage problems).


Maybe, in some industries this could be useful, but I think this is only a "one day wonder".
 
well considering the dougr comment - the firm`s problem might have nohing to the method they use. The same situationis with software. You could use the best one(maybe Pro\e?) but it does not mean You will make good things


But lets back to main topic and horizontal modeling. For me it is nothing new. It wasn`t named in this way but I think many designers already use it in their models. This method is use but poeple does not know they are using it.


There is also a problem how deep the associativity should be used. Sometimes it hurts not helps. In these situation You put some features like curves, planes, axes ahead, on top, to avoid the problem with to deep relationshp between feature. You can make in this way a structure devided in outer and inner geometry very quickly. For sure it could be use in creating models from existing documentation and while makin prototypes. But it costs more time, and specialy things that are "big" and change often could be done in this way.


The same one can meet already in assembly with skelethons. But I want to focus on the assemblies where the skelethons are used only for mounting not for building the components. So in this case one can avoid relationship between components and quick replace/remove without waiting for Resolve mode.


So for me this horizontal modeling sounds very fimilar what I already doing with Pro\e
 
All the concepts in Horizontal Modeling have been in our corporate Pro/E SOP for years. It is just common sense to make robust models that can be easily changed without failing. Pro/E makes it so easy to add dependancies, even to unintended references, that you need to try to limit them so that modifications don't make the regen fail and force you into resolve mode.

PTC have made several improvements in Pro/E to help users in this regard. The intent manager makes you pick references before sketching so that you don't end up snapping or dimensioning to some insignificant edge by mistake. The external reference control also helps keep unintended references out of your models. However, it is still entirely possible to build bonehead references in if you don't apply a little forethought while building your models.

I have a real problem with Delphi patenting common sense. The patent office has gone on far to long handing out patents for ideas in the public domain. Just look at the RIM Blackberry case. One judge is ruling against RIM while another is overturning the patents!
 
ncprog:


I've tried to find Top-Down Design Task Guide on the PTC.com site. Dou you know exactURL (or site section)to this PDF?
 
"All the concepts in Horizontal Modeling have been in our corporate Pro/E SOP for years."


How do you know that ?


I can't figure out what this does from all the "double talk".


wtf does "CAD neutral" mean ??


"they reference features to datum planes instead so they don't have to remove dependencies."


They're patenting that ???


As a rookie modeller (and still am) I learned to use "start-part" and always reference start-part features when possible -am sureevery one in this forumunderstands that ???


Delphi has selected Cadpo (www.cadpo.com) to provide a certified training program - think they mean "cadpoo" ??


Guess I can't model anymore as Delphi has the patent....
Edited by: dougr
 
> Guess I can't model anymore as Delphi has the patent...

Sure you can. At least until I get a patent on creating
Sensible (whatever That is) Dependancy Chains.
smiley5.gif
 
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