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Stablizing mates in large assemblies.

r2d2

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I'm in a pickle trying to get SW to work. I'm trying to start a business with a machine I am"building" in SW and am spending most of my time getting the software to work. SW could kill my business opportunity and financial situation. Here is the main problem:


The model is a relatively large assembly that has parts and subassemblies that need to move to check clearances. I've tried many different ways of mating the components (mating individual parts in,or bringing subassemblies into the main assembly, trying configurations to define positions) but in the end the assembly acts like a house of cards - one wrong move (which is usually a time consuming mystery to figure out) and mates break or conflict all over the place. SW will even delete mates and parts, or remate in wrong configurations all by itself.


How can I make my assembly mates more reliable, expecially the ones that change when a new position is required? Is there a good way to go about this or is SW just going to be too difficult or incapable of good results?
 
When you insert a part or an assembly into another assembly you need three mates (or one concentric and one distance mate) to fix it. When you add new mates and receive a message "this mate is over defining the assembly. Consider deleting some of the over defining mates" that means you did something wrong, this over defining mates could perhaps break your assembly. Otherwise, no such thing happened to me (deleting mates or parts all by itself)!
 
I have had times when this has been a problem and it stemed form having different configuration. some times Solid works pops out and error when a mate or featrue is suppressed in such a way that it shouldn't effect the rest of the part. For some reason it does. I have foung if you take such mates or featrues and place them into a file and then suppress the file then solid works does not see the mates or featrues and thus no error messages. To do this select the mates or features you want to suppress, (you can put many mates or features in one file if you want,) and right click and select add to folder. this will drop all the selected mates or features in to a folder which will allow you to suppress or unsupress all the featrues in the file at one time.
 
It sounds like you may be working on a project that's more complex than your experience with solidworks allows. Maybe a class might help you resolve some of these issues, community colleges often offer low cost classes.
 
I am not a specialist in SW. I don't design very large assembly, but I encoutered this problems ( not all ). I suggest you to test first the subensembly. Make yor subensembly RIGID and test the large assembly. And so on. If you are a sketch ( or more ) linked to another part(s) in an assembly,is a good ideea to break this links. A wrong position of a part can cause a wrong REBUILD and... cascade. another way ( it's my favorite ) is to supress AUTOMATIC REBUILD in the testing time. Of course, I supresssome mate(s) wich makes my assembly FULLY DEFINED.


I test the clearence. after that I UNsupress mate(s), the assembly move to initial position and... Do - LOOP .


Good luck ( I know: my english is poorley )
 
1.) Check when establishing mates is two square looking icons (underneath
the standard mate selections) for aligned or anti-aligned. Occasionally
I will add mates and what looked good a minute ago will all of a sudden
look like an exploded diagram until I click on the "non-activated" icon.

2.) What I've done is establish the mates in a "default" position of my parts in an assembly which should work in any position. Then I make new configurations based on different positions of the assembly. For example, one assembly using a cylinder in an extended position gets one configuration and another configuration in the retracted position. Then in the exteneded configuration I add the mates needed to restrain extended position and label them something like "extend Dist" or "extend coincident". Then I create the specific mates needed for the retracted position configuration and label them as "retract coincident" or "retract dist". The labeling of the mates will help any troubleshooting if needed in the future for starters.
 

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