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Subassemblies fail in Main assembly

3dcad3dcad Member, OS Professional, Mentor Posts: 2,443 PRO
Does anyone else have problems where main assembly shows errors on subassy and not functioning correctly while looking at subassy everything is good?

This happens to me all the time with certain standard part assemblies (hinges) even though everything is good when building main assy - it may be broken when come back after a while. Subassy is linked so it comes from locked version.

Sometimes this happens for local subassemblies too, those times there is usually mate or two red in subassy and the fix is to suppress and unsuppress and it's good for a while. 

I have reported this multiple times and had that hinge doc checked by Onshape but still struggling to keep things together.

Left column subassembly - right same version in main assy.

Kind hard to fix while there's nothing to fix..


  • romeograhamromeograham Member Posts: 465 PRO
    I have had this happen as well @3dcad . The subassy's in my case are very simple (no moving parts), but still the errors show in the top level assembly.

    Intermittent and low-impact for me, but a time-waster. Looks to me like this issue would impact the top level assembly's function in your case.
  • sebastian_glanznersebastian_glanzner Member Posts: 184 PRO
    Try this: Surpress the group mates in the main addembly and then unsurpress them.

    I had a similar error and this worked for me in the past. 
  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,443 PRO
    edited October 2019
    For me it used to be only some rare cases but recently I have bump into this more often - even up to a stage where it's difficult to work anymore. Like today.

    In my case it's usually the hinge sub-assy that's claimed to be broken and in main that throws doors around screen and bits of hinge assy flying around. 

    The most annoying thing that reminds me of traditional cad is that everything is good when making the assy and when coming back later it's like this:
    (there should be 6 functioning door fronts)
    Sometimes it's enough to grab the door with LMB and just shake for a minute and suddenly it jumps to it's correct position and moves like it should - sometimes not.

    Edit: This assembly doesn't even show any errors! :anguished:
  • lanalana Onshape Employees Posts: 554
    Apologies for the annoying behavior. Usually such issues end up being caused by us saving incorrect state in cache. We are trying to cache  computed state on document close to make it open faster next time. We've been fixing this sort of issues, but they are difficult to chaise.  Please when you see them - report them to support. Share the document, if you can, notice the time of opening the document , if not reporting immediately. This would help us to address the bad cache issues. 
  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,443 PRO
    @lana I always go first to support. I have reported this many times but as fixes have been suppress/unsuppress type and same problem coming up time after time again I wanted to see if I'm the only one or if there is others with similar behavior.

    15 pages in total, most of them improvement requests
  • glen_dewsburyglen_dewsbury Member, OS Professional Posts: 154 PRO
    I have seen this behavior.
    Happens when 1 mate imposes over an other mate. Both can't be right.
    Grouping the parts in the  main assembly will cause mates in sub assembly to show as an error when viewed from main assy.
    For me it's when I'm in a rush and don't want to take time to finish mating sub assy components to get the proper behavior in the main.
  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,443 PRO
    They found something on the assemblies (on software). Hopefully gets it fixed.

    I don't do main assy groups. All these I'm talking about are completely fine at first but break by them self while no one is accessing the document.

    One thing I learned today is that planar and parallel mates are expensive and apparently can't be used to connect two (or more) moving parts move together. At least not without problems.
  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 1,471 PRO
    I haven't noticed changes propagating down the chain from sub to top. 

    I'll watch for it.....

  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,443 PRO
    edited November 2019
    What we are looking here is cabinet with 3x door assembly, door assy using linked hinge to provide realistic movement. Should be doable?
    Well at least it was when I modeled this back in 2017.

    Now Onshape claims that one of three door assemblies have problem with mates and throw that hinge piece flying around. But they come from same subassy - how is it even possible that two is good and one fails?

    When first accessed this tab, there was 2/3 fail but with just simply grabbing the door and shaking mouse with button pressed for 1-2 min it suddenly start moving and problem wen't away.

    Support has been very helpful and all over it but not being able to make the problem go away.

    It's a bug - there is no way to fix by modeling. A simple 12 part hinge just seems to be too much at the moment.

    But Onshape has the history, let's go back to here - and *zap* all good again  :|

  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,443 PRO
    And after couple of hours suppressing, refreshing, unsuppressing, banging head to table - it suddenly works out. Never left this tab nor otherwise accessed subassy / parts in other windows.

    Let me present you fully functioning cabinet with 3 doors moving flawlessly within realistic limits - without any errors.

    And can't make it fail anymore no matter how much I slam the doors.
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