Best types of assemblies
Best types of assemblies
(OP)
So, I have been searching for explanations on different types of assembly methods and can't find any good information. I am interested in the pro's and con's of using the following types of methods on a large vehicle design with many many assembly options. I am afraid that I will be limited to using unique sub-assemblies for each option we have, but want to make sure I am not counting out other methods. I am currently aware of the following:
Multiple assemblies with common cord sys. When used with Sim Reps, seems to be pretty powerfull. I am afraid that I will end up with 100-150 individual assemblies which may take time to update.
Multiple assemblies with Skeletons: I am a little gunshy about skeltons. They don't seem to offer any advantage over option one (especially when using mechanism) just more overhead in keeping the skeltons up and running.
One big assembly and Pro/Program: I don't know much about this, but am not sure if keeping 10 sets of 50 parts (some used in multiple sets) at various positions will benefit my sanity.
Family tables: seems to be a similar situation to Pro/Program
If anyone has a solid opinion on the good, bad, and ugly of these, I would love to hear it. I have done a little searching on the internet but not found an all inclusive article; if one is available, I would appriciate a link. Looking forward to available advice.
Multiple assemblies with common cord sys. When used with Sim Reps, seems to be pretty powerfull. I am afraid that I will end up with 100-150 individual assemblies which may take time to update.
Multiple assemblies with Skeletons: I am a little gunshy about skeltons. They don't seem to offer any advantage over option one (especially when using mechanism) just more overhead in keeping the skeltons up and running.
One big assembly and Pro/Program: I don't know much about this, but am not sure if keeping 10 sets of 50 parts (some used in multiple sets) at various positions will benefit my sanity.
Family tables: seems to be a similar situation to Pro/Program
If anyone has a solid opinion on the good, bad, and ugly of these, I would love to hear it. I have done a little searching on the internet but not found an all inclusive article; if one is available, I would appriciate a link. Looking forward to available advice.





RE: Best types of assemblies
Bottom-up :component parts are designed and edited apart from their usage in a higher assembly.
1.Create part solid models.
2.Combine parts into sub-assemblies.
3.Combine sub-assemblies into assemblies.
Top-down :the hierarchy of assemblies and sub-assemblies is designed first,then part solidmodels are designed in place.
1.Create highest level assembly.
2.Add empty sub-assemblies and parts to assemblies.
3.Create solid models in empty part files.
Best Regards,
Heckler
Sr. Mechanical Engineer
SW2005 SP 2.0 & Pro/E 2001
Dell Precision 370
P4 3.6 GHz, 1GB RAM
XP Pro SP2.0
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Do you trust your intuition or go with the flow?
RE: Best types of assemblies
RE: Best types of assemblies
Hope this helps.
Best regards,
Matthew Ian Loew
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Best types of assemblies
Also, I have been building my models with a Master_Base model that has all the connection points for the subgroups (we have about 8 of them) instead of using skeletons. I just don't appriciate the knowledge base required to utilize skeletons and think I am getting the same functionality with a single base model. The only advantage that I see ist that if sub assembly has a lot of datum point/curves it could get crowded. Is there something I am missing?
RE: Best types of assemblies
Skeletons are not included in Bill of Materials reports or mass property calculations (if they are just datum featres it wont matter). Many part templates contain layers for skeletons as well, making them easier to blank out.
They also show up with a different icon in the model tree, but like you I append their name with _SKEL or some other distinguishing name.
RE: Best types of assemblies
Maybe I am not keen on skeletons since our envirenment isn't structured to take advantage what it offers. Am I missing anything on this?
RE: Best types of assemblies
Something that should be interjected regarding utilization of skeletons and the overall TDD approach is the capability to drive your design (and its permutations) by means of a layout and parameterization. The layout is defined in Pro/E as an upper-most level in the TDD within which you establish and control the major design characteristics for you program. Generally it consists of an illustration to help identify those major features, as well as data tables that actually drive the design. These tables are populated by parameters, defined to control your key characteristics. Individual parts, assemblies and skeletons are "declared" to the layout, which then allows the layout's global parameter values to drive their size, position, etc.
One commonly used analogy is that of an engine design. Primary characteristics like bore size, number of cylinders, displacement, valve positions, and so forth can be defined by the parameters mentioned in the table above.
As the design evolves, the layout provides a central location from which to alter all of the downstream components and subassemblies, thereby reducing the potential for mis-fits just because someone forgot that changing the cylinder bore size required a corresponding change in piston diameter (for example). Since access to modify the layout is generally restricted to the project lead, unauthorized "tweaking" of the primary design dimensions is avoided also. Which means that to change a part that is controlled by a global parameter, the modification needs to be done in the layout. So you maintain control of your connecting rod's pin to crank length, pin & journal diameters, even though the subcontractor who's working on that part design has the freedom to optimize the rest of the part's geometry.
Overall, a very powerful tool that can help to organize and control the most critical project characteristics and allow them to be communicated thruout your business to keep all players supplied with the most up to date data.
Ed Leitkowski