Making Assembly Mates Stable
Making Assembly Mates Stable
(OP)
I am trying to create a moderately large assembly in SW2005 that allows for movements of parts and subassemblies but have had headaches trying to keep the mates from conflicting, breaking, or just disappearing (with parts and subassemblies at times). I have tried mating the moving components in the top assembly, mating them in subassemblies with flexible properties in the top assembly, and trying to use configurations in both sub and top assemblies. SW assemblies seem like a house of cards, one false (and sometimes inscrutable) move and the whole mate scheme blows up!
I am looking for ways to make larger assemblies with moving parts mate more reliably before struggling with SW brings to whole project down. Any help would be appreciated.
I am looking for ways to make larger assemblies with moving parts mate more reliably before struggling with SW brings to whole project down. Any help would be appreciated.






RE: Making Assembly Mates Stable
Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
http://sw.fcsuper.com/index.php
RE: Making Assembly Mates Stable
Sometimes I have to make a "cheat" configuration. For example, I will mate 1 half of the hinge to 1 part, and 2nd half of the hinge to the other part. This is for a simple hinge assembly. For more complex assemblies, flexibles are a headache.
SW07 SP2.0
Flores
RE: Making Assembly Mates Stable
Mate plane to plane
Stay away from angle mates
Save and save often
"Art without engineering is dreaming; Engineering without art is calculating."
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: Making Assembly Mates Stable
The biggest essential hint I stick with is to mate things one to another based on something that won't change in the part/subassembly. Hence, the suggestion to mate using planes above--your primary three planes don't change or disappear, so they'll be where you expect them no matter what you do to your part. You can apply this to other stable/non-changing geometry--whatever isn't subject to being altered along the way, and therefore crashing your mates. A prime example of weak things to mate with is surfaces, edges, sketch entities (unless used as a geometry-driving skeleton sketch), holes, etc.
In my experience, most of the trouble doesn't come from SolidWorks, per se, but from slight logical faults in building up geometry or assemblies. Of course, knowing how SolidWorks "works" is necessary to get the logic rules down properly--but can save huge amounts of time.
Jeff Mowry
www.industrialdesignhaus.com
Reason trumps all. And awe transcends reason.
RE: Making Assembly Mates Stable
Sorry, I know it's evil, but it hit me as funny in a weird way.
RE: Making Assembly Mates Stable
Jeff Mowry
www.industrialdesignhaus.com
Reason trumps all. And awe transcends reason.
RE: Making Assembly Mates Stable
Windows XP / Microsoft Wireless Optical Mouse 5000
SolidWorks 2007 SP1.0 / SpaceBall 5000
Lava Lamp
www.Tate3d.com
FAQ376
RE: Making Assembly Mates Stable
I do not need to animate the machine, just check part clearances, linkage interaction (double hinges, four bar, etc.) and actuator stroke requirements at different positions. Configurations may be the best approach, but that seems to have its limitations and I have some questions about that function also.
What I have learned:
1. Keep an eye on flexible subassemblies. I will see if reducing them will help.
2. Try mating to planes, especially ones defined off the 3 main sketch planes. However, many times that is hard to do and mates should simulate how parts actually align.
3. Still looking for the "Make Mate Stable" option. Send that one to SolidWorks, I hope they find it more than funny!
Bob Davis
RE: Making Assembly Mates Stable
Hope all is great. I am actually working with some large assemblies and here is a few things that have helped me with mates:
1) There is a Best Practices for Mates on the SolidWorks 2007 Help (e.g. avoid long "chains" and mate "loops" of components)
2) Avoid redundant mates
3) Do not mate to a component that has been patterned
4) Limit mates and flexible subassemblies take longer to solve
5) Try to mate everything to one or two base parts or a layout/skeleton sketch
6) If possible fully define the assembly as TateJ said "motion is over rated"
7) Submit an enhancement request for a make mates more stable option
Cheers,
Joseph
RE: Making Assembly Mates Stable
OK... here is an obvious tip to avoid mate issues, "use subassemblies" (it may seem obvious, but I have overlooked this one many times)
RE: Making Assembly Mates Stable
The problem with this is that SW tries to solve for the first, and then apply its solutions to the second cylinder, which isn't really at the same place it thought it was. SW rapidly goes south at this point.
The solution to this problem is to make a second, identical configuration in the hydraulic cylinder sub-assembly. By placing two distinct configurations of the hydraulic cylinder in the main assembly, SW must solve for both of them separately, even though the configurations are identical. This process solved a very aggravating persistent problem for us.
TJ McDermott
Formost Packaging Machines
RE: Making Assembly Mates Stable
An excellent tip... A star for you.
Regards,
Anna Wood
SW07 SP2.1, WinXP
Dell Precision 380, Pentium D940, 4 Gigs RAM, FX3450
WD Raptors, 1 Gb network connection
http://designsmarter.typepad.com/solidmuse
RE: Making Assembly Mates Stable
I'll take credit though, for spreading the idea far and wide. This is something that needs to be taught in the class provided by the VARs. It took TWO YEARS of flexible assembly frustration before we learned of it here in this forum.
TJ McDermott
Formost Packaging Machines
RE: Making Assembly Mates Stable
Thank you for spreading the idea. Another Star for you.
Bradley
SolidWorks Professional x64 2007 SP2.2
Intel(R) Pentium(R) D CPU
3.00 GHz, 3.93 GB of RAM
NVIDIA Quadro FX 3400