part vs. assembly
part vs. assembly
(OP)
when creating a top down assembly I am often confused as to which plane to sketch on. I could choose a plane from the assembly or the part. Normally they coincude but sometimes they dont. Will one cause a problem. If i draw a part feature on an assembly plane can the part exist outside the assembly. Will it cause a problem? What about if I change something in the assembly and then that causes the pieces to not line up properly? Also is it possible to create the part based on its location in juxtaposition to another part and them move it elsewhere and use mates to position it. Will the features referenced elsewhere in the assembly have a problem updating? Any input is appreciated.






RE: part vs. assembly
RE: part vs. assembly
If you design in such a way as to gain this independence with your models, you'll have a more robust and independent database of parts.
In the case you mentioned, I normally insert a new part into the assembly and build from there. When I'm finished with referrals to other parts within the assembly, I eliminate them and constrain them within the part's own sketches/features.
Jeff Mowry
www.industrialdesignhaus.com
Reality is no respecter of good intentions.
RE: part vs. assembly
RE: part vs. assembly
Also, note that if you do make edits in the new assembly, the part will update in the old assembly (if the parts are in the same directory).
This brings up document control issues. If the same part is truly the same part (no differences), feel free to use it in several assemblies. If you make any changes, you should change the file name (Save As. ..) so things don't get confused. When you open an assembly, the parts are called into the assembly by file name.
Between major revisions, I normally will open my "master" assembly (that holds all parts and sub-assemblies) for the project, create a new directory (such as 050103 for today's date, within a project directory such as Piston Engine 01), and hit File, Find References, Copy to copy all parts referenced in my "master" assembly into the new directory. I then close the assembly and open the assembly in the new directory to make any changes for the new revision.
This practice is very basic and leaves a good document control trail. It won't work in many scenarios, however, such as multiple people accessing the same parts on a server. In that case, you should consider PLM software or some other document control practices. It's also critical to have a regular back-up process so files cannot be lost in case of a hard drive failure, fire, etc.
Jeff Mowry
www.industrialdesignhaus.com
Reality is no respecter of good intentions.
RE: part vs. assembly
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RE: part vs. assembly
RE: part vs. assembly
Eng-Tips:-
Intelligent Work Forums For Engineering Professionals
RE: part vs. assembly
this piston has to be able to move. therefore, is it better to create in context and keep it locked in place (using converted goemetry "on edge" for example) or to create each part separately and then use mates?
Idealy i would like to have all parts in context for a true top down design yet still be able to move them as if they mated. Is there a solution that would allow for both? What if its driven off of a spreadsheet? they have to move but i want all the parts to update automatically by either editing a layout sketch in the assembly or changing values in the chart.
RE: part vs. assembly
RE: part vs. assembly
Regards,
Scott Baugh, CSWP
3DVision Technologies
www.3dvisiontech.com
www.scottjbaugh.com
FAQ731-376
FAQ559-716 - SW Fora Users
RE: part vs. assembly
Designing in context locks the part in place. although i can unlock the part and move it around, doing so will create errors in the sketch since part geometry, features, planes, etc. have refernces to the assembly.
Is there a way to have a part's dimensions driven from an assembly sketch yet let the part move as if it's independant?
Can this be done in conjunction with a spreadsheet and will it help or just complicate everything. It would be nice to be able to make several variations of the assembly just by changing some values but it is important that that the parts do not remain static.
Is there SW feature that i am not aware of or am I just going about this the wrong way.
RE: part vs. assembly
So, you can create a part in the context of one assembly, then move the parts into another assembly for movement. However, in doing so, you cannot edit the part in the context of the new, movable assembly because that creates logical problems. Each part can have dependent relations in one assembly only. I don't recommend doing this sort of thing, since the possibilities of error compound through the complications it presents (not best practice).
Is it possible to eliminate the dependent relations and keep the relevant parts within their native assembly or will you continually need to roll updates through several parts with their dependent relationships?
These are part of the growing pains in learning "best practices" along the way. Eventually, you'll come to a good set of planned actions before starting assemblies and even parts that will make this roll along much more smoothly--just takes a lot of practice and experience with understanding (difficult to convey in a "teaching" way or tutorial).
Jeff Mowry
www.industrialdesignhaus.com
Reality is no respecter of good intentions.
RE: part vs. assembly
Jeff Mowry
www.industrialdesignhaus.com
Reality is no respecter of good intentions.