Fully Define Everything or Not? 1

[BodyBagger]

Hello all,
I am just curious but how many of you fully define every part in an assembly (washers, bolts, etc?) Or do you allow the circular items to spin freely? Does having everything fully defined have any benefits or does it hinder things? Your thoughts and practices would be appreciated.

BB

 

[Overworked1]

I tend to leave fasteners underdefined (able to spin). Virtually all other components I will completely mate in place. I can tell when things are slow at my company by looking back at assemblies I have done and seeing the fasteners fully mated.

Aaron
SolidWorks (x64)/PDMWorks 09 3.0
CADKey 99 R1.0 (Yes, still using it!)

 

[CorBlimeyLimey]

Having all parts fully mated helps when trying to find which parts aren't ... if that makes sense?

Having all parts fully mated will decrease rebuild performance in large assys.

I usually allow symmetrical fasteners to rotate, but always fully mate non-symmetrical and product parts.

 

[MadMango]

CBL, at my last user group meeting we were told the exact opposite, that having all parts fully mated will increase large assembly performance. This was due to the software not having to define the extra DOF. I currently don't work on large assys (maybe 200 parts), but have started to fully define all hardware models, but haven't notice a pro or con yet.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of these Forums?

 

[drawoh]

BodyBagger,

I fully make everyhthing. I can scan quickly down through the assembly browser and satisfy myself that all my critical components are completely mated.

The assembly on my screen at the moment has 1726 components, 387 top level components and 526 top level mates. If your stuff is simpler, you can be a little more flexible.

I have just experimented with some flexible assemblies, and it all has been fairly successful. This will affect some of my mating practise in the future.

JHG

 

[Eltron]

I leave mine underdefined as well.

Dan

http://www.eltronresearch.com

Dan's Blog

 

[ShaggyPE]

I used to fully constrain hardware... now I am in the mode of not putting in the parallel mate to clock them. I made that decision based on this article.

http://www.fcsuper.com/swblog/?p=140

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist

 

[ShaggyPE]

The primary reason I liked fully mating the hardware like the others have mentiond was so I could quickly scan the tree to see if something was loose. A way around that is to put your hardware in a folder. That way, if it isn't in the folder, it should be fully constrained.

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist

 

[MadMango]

Well, those are fairly convincing numbers...

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of these Forums?

 

[CorBlimeyLimey]

MadMango ... I was trying to say that more mates would worsen performance (ie make it slower).

You were told that having more mates to solve would improve performance? Or am I misinterpreting again?

 

[ShaggyPE]

CBL,
I used to hear things like that too. Along the lines of "undefined location" results in extra thinking for SW.

I was really pleased to see the article.

-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist

 

[Updraft]

I like the idea of the Folders - something I don't take enough advantage of.

One area that I believe (because I haven't performed timed comparisons) is that subassemblies are underutilized. Mating components into their appropriate subassy means all you have to do is maintain that subassy and mate it.

I have been on a tear lately with one of our latest products to drag fasteners applied in the top level assy into the subassy they are attaching. Such a sweet ability in SWX!

Sometimes I make a subassy of a fastener set, i.e., bolt, washer(s), nut and then insert that subassy using the derived pattern from a hole wizard set of holes. NICE!!

Some folks object to this technique due to the default affects on a BOM, but a little knowledge of BOMs reveals easy ways to make these subassemblies or their components show the way you want.

- - -Updraft

 

[BodyBagger]

After seeing the input here, I am no longer fully defining hardware.

BB