Assembly Tip and Time Saver 7

[3dlogix]

Problem:

You have a large assembly and you need to modify a part that is a parent for almost all the other parts in you assembly. Doing so will cause the other parts to fail and you may need to redefine them all.

Solution:

Determine which parts are children of the part that you wish to modify. Then redefine these parts and replace the assembly constraints with the FIX option.

Now go ahead and modify the part and then redefine each child to new or modified references. The FIX constrant will lock the parts in their last position, but relative to their origin CS and the assembly CS. So you will not see the FAIL REGEN window, and this is a big advantage, since you also keep the parts in their original locations.

Steve

http://www.3dlogix.com

 

[TORGON]

I find the "FIX" option a bit rough to use... It does work... But you loose the reason for having all those relationships in the first place... Meaning that when you change something... Everything is "fixed" in the old location... not normally what is intended...

I personally go through the trouble of freezing what I can and supressing what I can't... then what happens "most times" for me is once you redefine the first frozen object... all the rest "unfreeze" because of they are related to the first... and then I resume the rest... (I'm doing alot of piping right now and I have to do this ALL the time *sigh*)...

Of course this doesn't always work... but it does make sure that your model continues to update as you would expect it to...

(I just don't trust most others to go and fix the "Fixed" objects after changes... they'd probably think it did it automatically... as Pro/E is *cough* famous for)... Daniel Pro/E Specialist

http://www.torgon.com/

 

[3dlogix]

Daniel;

Your comments are correct, in that the FIX option does not always update the part locations as you may want to since your are only placing the part w-r-t the part default CSO and assembly default CSO.

I mentioned the FIX option because this allows you to keep the previous assembly constraints (like MATE and INSERT) but UNSELECTED. It is possible to have MATE, INSERT and FIX all together. So the FIX actually prevents items from being Packaged. And we all know the ramifications with Packaged parts.


Steve

http://www.3dlogix.com

 

[TORGON]

Ahh... that is a very good point... By unchecking the original constraint options you can go back and correct them later... Hard part is getting people to go back and fix them sadly...

I was only making my comment because some people may not be aware of the the ramifications to using "fix"... I know that people here (at the site I am at) have used it thinking that it actually "fixed" (corrected) the problem... and then later on were complaining that the models were not behaving correctly and blaming the software...

I never said it was a bad tip... Daniel Pro/E Specialist

http://www.torgon.com/

 

[3dlogix]

Don't worry Daniel, your tips and input are always welcome. I understand your "pain", I work with many ProE-people on-site at the client's, and the horror stories I hear and see.

ProE years under someone's belt doesn't mean anything, it's the quality of their experience. I am sure you see the same with your client's.

Steve

http://www.3dlogix.com

 

[im4cad]

I think the best way to handle large assemblies is using coordinate systems for assembling, so you can delete any part anytime and the other parts are not affected. If not, at least using as much as you can the default datums (or new ones) instead references from other parts help a lot.

im4cad

 

[darcyo]

the fix constraint sounds a lot like a method that i sometimes use. has anyone used the transform cordinate system method? this is good for fixing large modules in place relative to the entire model. for example, the placement of a bus powertrain module can be fixed indefinately against the bus as a whole, thus breaking top down associativity. anyway, here's how it works:
- analysis > measure > transform
- select two coords (one from a top level assy and one from the assy that you want to fix).
- write the transformation data to a file (from the analysis window)
- then within the top level assy, create a coord system > from file, and type in the name of the saved transformation data file.
- rename that coord, ex. 'powertrain_csys'
- the assemble the powertrain subassy to powertrain_csys.

if that made any sence, i hope it is useful. its a good way of breaking top down associativity between subassys that don't really need it.

 

[pascual]

I use a little trick to draw that could be of help. When I'm not sure if some part will be modified, I sketck a curve related to the part. In this way, when I modify the part I must redefine the curve but not the drawing. This could be applied to assemblies as well by appling the relations to this curves.

 

[gkc]

nice and valuable discussion, - but I think the PROEngineer facility skeletons need to be mentioned. By creating an assembly skeleton and then assembling parts and subassemblies which only reference the skeleton the problem of regenerating the assembly after changing or replacing a component disappears.
(I'm aware that part to part referencing can be valuable or even indispensable in some cases - so what I'm suggesting is not a "universal" solution)