I have tested some options and discovered that using GV’s (Global Variables) in an Assembly with Sub-Assemblies can be a mess, when not organized.
I designed a special model to test some things. The model is a roughly a flexible hose with flanges and fasteners, showing a straight position and a bended position in different Configurations. I choose to use SSP method because it is well organized by default. Since the SSP-part is driving almost everything, it first seemed logically to put all the GV’s in the Equations of the SSP-part.
All the Parts can pulll the GV from the SSP-part, and also the Main-Assy can pull the GV from the SSP-part.
However, the Main-Assy has patterns which are controlled by some GV’s. If the GV is defined in an Equation of the SSP-part, than the information has to be pulled from the Equation in the Main-Assy and be pushed back to Feature in the Main-Assy. This seems not robust enough to me. The other option is to split the GV’s in the SSP-part and in the Main-Assy. This will be fine until you want to control the GV’s with Configurations and a DT (DesignTable). Than you have 2 different DT’s in 2 different files! I decided to put all the GV’s in Equations of the Main-Assy. The model is included.
- - is this the best way to handle GV’s in an Assembly?
- - The labels do not scale nicely, do they need to parametrically controlled by the DT ?
- - Ideally, the size of fasteners has to be also controlled by the DT (working on it).
900-MainASSY.zip 3.5 MB
Looks like the best approach possible right now to me.
Have you used this on a large scale already?, first look seems like the approach to go with. - Had a lot of problems with huge saving times at piping/media assemblies with external references to the respective interfaces in the buildings.
Nevertheless changing the same dimension in numerous parts when modifying a design in monkey work style is no proper approach in any way either.
When driving this further i think the limits are where a CAD Configurator comes in.
Hi Alexander ,
I have not used it on large scale, the model was just an example.
Actually I have decided to leave this subject untouched for the time being, because I'm running out of ideas to create a nice parametric model.
The combination of fasteners, labels and all other dimensions and configurations is more difficult to manage than I thought.
Another dilemma thing:
If I manage the configurations for fasteners with a design table in the main-assy, than the fasteners have to be components in the main-assy. I'm afraid this will reduce main-assy rebuild performance very much.
SSK works fine, but it's also possible to link Global Variables directly both ways Top Level <-> Parts/Sub-assemblies.
Hi Vladimir ,
What do you mean with SSK ?
Yes you are right, most Global Variables can be linked to and from sub-assemblies and parts.
The fact that this is possible is really nice, but also difficult to manage.
Not all possible combinations of values in GV's wil create a usable model without errors.
I want to controll only "useful" combinations of GV's and their values in the Design Table.
See also my answer to Alexander.
Sorry - I mean SSP (Skeleton Sketch Part).
Beside Design Table, GV's and links between GV's can be also managed directly by Equation Manager.
Usually this is my way to go.