Subassembly Hierarchy

[tmalinski]

I have a ton of components that seem like good candidates for sub-assemblies. Some of the sub-assemblies could actually be inserted into other sub-assemblies to make nested sub-assemblies. The nested sub-assembly would then be inserted into the main assembly. Does this sound like the best approach? or should I insert all of the sub-assemblies into the main assembly at one level? I think using nested sub-assemblies might give me the most control when using configurations showing positional changes of components. I have heard others say the best practice is to insert all of the screws at the main assembly. But if I have nested sub-assemblies wouldn't its screws be inserted at the sub-assembly level?

sorry if this is confusing.
Tom

Tom Malinski
Sr Design Engineer
OKay Industries
New Britain CT

 

[CorBlimeyLimey]

Assemblies and sub-assemblies should reflect the actual methods of manufacture, assembly or storage. If a sub-assy is built and/or stored as a separate process and part number than other sub-assys and top level assy, then that is the way it should be modelled.

 

[Theophilus]

I do the nested form all the time--with the requisite hardware/fasteners. (If it's a subassembly, it's a subassembly--fasteners are needed.)

I like to keep my top-level assembly light-weight, uncluttered, and agile. Few mates means few problems. Plus, this sort of thing is simpler to animate, depending on the complexity of the motion you need.



Jeff Mowry

http://www.industrialdesignhaus.com

Reason trumps all. And awe transcends reason.

 

[tmalinski]

Thanks Jeff, thats what I Thought

CBL In my case, I'm working on tooling die components and assemblies that are all part of one P/N. The tool is one of a kind, but is mage up of many sub-assemblies and components.

Tom Malinski
Sr Design Engineer
OKay Industries
New Britain CT

 

[AnnaWood]

Tom,

I use sub assemblies all the time in my dies.

Makes it easier to manage the die.

Keeps things modular for easy re-use and cloning, etc.

Makes it easier to send out partial releases when doing concurrent design.

Keeps the top level clean and the top level mate count lower.

Probably lots more things I am not thinking about at the moment.

I also organize my stuff into folders within the top level asm.

Feature driven patterns are your friend when used with hole wizard holes.

The old concept of having all the details in one top level asm for the BOM are just that, old concepts. Same goes for having all the die asm details in one multi-sheet drawing file.

Regards,

Anna Wood
SW 2007 SP2.2, WinXP
Dell Precision 380, Pentium D940, 4 Gigs RAM, FX3450

http://designsmarter.typepad.com/solidmuse

http://www.phxswug.com

 

[SolidAir]

Tom,

Something else to consider is whether you will be inserting any flexible sub-assemblies. They are only flexible one level up.

I myself prefer not to use sub-assemblies unless there is a good reason to (re-use, limit top level mates to under 300). The more sub-assemblies you have, the more models to manage. If you start making configurations and each sub-assembly has a configuration to match, then you increase the amount you have to manage.

One final thought fpor right now: sub-assemblies can also cause problems with making exploded views and auto-spacing.

SA

 

[tmalinski]

Thanks for your help, I'm leaning towards multiple sub-assemblies as our standard. I like the way they work for the most part and managing configurations seems to be a small price to pay for the organization and other benefits gained. I also don't often use flexible sub-assemblies any more.

Thanks
Tom..

Tom Malinski
Sr Design Engineer
OKay Industries
New Britain CT