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Multi-part studios in assemblies

3dcad3dcad Member, OS Professional, Mentor Posts: 2,475 PRO
Onshape has worked hard on multipart studio and it feels pretty good these days.

But what happens in real situations when we begin to take them into assemblies?

Have you had questionable situations where you don't know what happens or situations where happened things you certainly didn't expect?

I have one main concern that hasn't been addressed in current build. If I use pattern or mirror and Ons creates multiple similar parts, how do I make them to be the very same part (same partid in documentation, one part in BOM)?
Assembly shows each part as their own in insert dialog, if I choose to import whole studio; My car would have 4 different tires even though they should be just one part x4.

Few days ago I was playing with a model and wanted to create assembly in early stage to see the functionality then I wen't back to ps and edited parts. I edited some cut out which divided un-intensionally the main part in two separate parts. This caused my assembly to break since it lost one part that had mates to other parts. Onshape created new id for second piece of original part and only original id was left into assembly.

This was caused by me not choosing all the needed regions for cutout and one small piece was left behind which then created a new part and stole the id from my main piece. I didn't expect it to brake my assembly but it did.
This was fixed by removing the small piece.

But what if that was my intension to divide a part into many parts? If I modeled a car from one piece and took it to assembly add tires to see the shape. Then go back to ps and separate doors and glasses to their own parts, would you expect to see the 'car' still in the assembly?
Only one part would stay in assy and it might not be the one where the tires were mated. It's easy to insert the new parts, but what happens to mates?

  
//rami

Comments

  • andrew_troupandrew_troup Member, Mentor Posts: 1,584 ✭✭✭✭✭
    @3dcad: are you using assembly mates to capture motion (eg wheels turning) or are you also using them for relationships which are static? 
  • brucebartlettbrucebartlett Member, OS Professional, Mentor, User Group Leader Posts: 2,140 PRO
    @3dcad right from early days with Onshape I have had this issue, one of my first designs was a 4 cornered trolley which had parts mirrored to each corner, duplicating some gussets up to 12 times. Onshape has come a long way since then and now has a lot more tools but this is still not solved for me.

    Every time I do a mirror or pattern of parts in a part studio I end up with more parts not instance's of the original part. Sometime's this is exactly what I want, but more often than not I just want instances of the original part in which case I can move over to the assembly to create my instances of which currently I can only do by mating. Now I have too move back to the part studio to add more parts/features but I am not seeing my full design. Ie. if it was the car I'd only see 1 of the 4 wheels in the part studio. I can use the part studio pattern or mirror but don't like to as I end up with duplicate parts, it's also confusing for others coming into the part studio and understanding which are the driving parts.

    A Pattern and Mirror in Assemblies will go part of the way to solving this and I think we will at least see patterns in the near future.

    I have thought that I would like to see part instances in the part studio but not completely sure on this. I see you can not add a Part Studio to a drawing and I'd Imagine that Part Studio's also will not have BOM functionality, it's very quick to add a complete part studio to an assembly and perform a group mate however you could mount a pretty good argument for complete parts studio to going into Drawings and to have BOM's. 

    I have tried deriving a part out of a Part Studio and back in but it's very sensibly not allowed because of circular references therefore this is not a workaround for part instances in Part Studio's and still would not give you patterning and mirrors. 

    At the end of this I think my biggest concern after patterns and mirrors are added to the assembly will be being able not see my complete design in a part studio without part duplicates and having to use a combination of Assemblies and Part Studio for a rigid part. Maybe we could have some form of ghost parts, parts which are instances in Part Studio's but immediately obvious which part is the driver. 
    Engineer ı Product Designer ı Onshape Consulting Partner
    Twitter: @onshapetricks  & @babart1977   
  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,475 PRO
    @andrew_troup I'm testing real situation where I would first use a lot of group mates and as the model begins to get it's shape then add functionality by separating parts and connecting with mates to get doors open and wheels turning. I'm not modeling a car, it was just example that everyone can understand.

    @brucebartlett You raise many good points and I agree with all of them. It is not easy for Onshape to come up with clear workflow between multi-part studios and assemblies. But as it is work in progress and we get updates every few weeks with appropiate feedback they can narrow down these anomalies one by one.
    //rami
  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,475 PRO
    Just as reminder for new people, there is improvement request open for voting:
    https://forum.onshape.com/discussion/1445/assembly-level-pattern
     
    //rami
  • andrew_troupandrew_troup Member, Mentor Posts: 1,584 ✭✭✭✭✭
    It seems to me (as a minimum) that when they arrive, Assembly patterns should be implemented to (should the user wish, on shifting parts from a Studio) automatically be generated, adopting the settings, including seed instance(s), of any pattern(s) in the Part Studio.

    And this link would need to remain intact, so that changes to the PS could be propagated by the user with minimal fuss to the Assembly.

    This part doesn't seem to me unduly hard. 

    @3dcad raises some interesting challenges to do with mates breaking when the parts get modified - but to some extent that's a problem with trad MCAD - i guess the main diff is that in trad CAD you can see things turning to custard as you make the changes, if you are editing parts from within the assembly.

    But at least in Onshape there are a lot fewer mates to be repaired, and not the same potential for "rivers of blood" arising from relatively small edits,. because the heavy lifting of orienting a part in Onshape is not shared between multiple mates.
    What's more, generally it's much easier in Onshape to lock down each degree of freedom only once, greatly reducing the incidence of conflicts.

    What I personally have more concern about, by way of future essential functionality, is configurations (both PS and Assy)

    I'm having a lot of trouble getting my head around how the collaboration capabilities and (even more to the point) the archaeological-strength history record we presently enjoy might be kept usably simple, once we have different "versions of reality" both historically and in the present, in the form of configurations.
  • joris_kofmanjoris_kofman Member Posts: 59 ✭✭
     it's very quick to add a complete part studio to an assembly and perform a group mate however you could mount a pretty good argument for complete parts studio to going into Drawings and to have BOM's.

    The main problem with this is that the assembly will not be updated with part positions (relative to each other), so you have to delete all parts of the assembly and insert them again to get the positions right. Doing this breaks all ties to dimensions in the drawing module, and whatever mates are in the assembly studio.
    It seems to me that one should be able to bypass this part. What I think we need is the ability to group parts in the part studio so all the static assembly work can be done simply by drawing the parts, doing patterns etc. and then grouping (sort of like creating a composite part).
    In the assemblies you would then only need to add the mates that drive the movement that you want.

    If we could just do a grouping in the part studio we would save a lot of work by saving a lot of mates that simply fix one part in relation to another. And you introduce many fewer features that can break, because they are in essence not needed.

    Every time I do a mirror or pattern of parts in a part studio I end up with more parts not instance's of the original part. Sometime's this is exactly what I want, but more often than not I just want instances of the original part in which case I can move over to the assembly to create my instances of which currently I can only do by mating
    Is a mirror without creating of the mirror body not simply a transformation? In this case should you not be able to use the transform feature (using mate connectors if need be) and still have your whole design in the part studio, and not have to do the assembly part at all. Of course this would be even easier if there was an option in the mirror feature that allowed the mirror feature to only do a transform operation.

    @andrew_troup in what situation do you actually at the moment need a part pattern in the assembly studio?
  • andrew_troupandrew_troup Member, Mentor Posts: 1,584 ✭✭✭✭✭
    edited November 2015
     it's very quick to add a complete part studio to an assembly and perform a group mate however you could mount a pretty good argument for complete parts studio to going into Drawings and to have BOM's.

    The main problem with this is that the assembly will not be updated with part positions (relative to each other), so you have to delete all parts of the assembly and insert them again to get the positions right. Doing this breaks all ties to dimensions in the drawing module, and whatever mates are in the assembly studio. .................................. 
    My understanding  is that assemblies should update group mated part locations in an assembly when they're relocated in the Part Studio.

    I asked this exact question in this post
    https://forum.onshape.com/discussion/comment/8828/#Comment_8828
    and the post from @jakeramsleyimmediately below mine affirms my understanding. In a subsequent post, he proves it.

    It would be good to get to the bottom of why it doesn't seem to be working that way, at least for some users.



    @andrew_troup in what situation do you actually at the moment need a part pattern in the assembly studio?
    In the example mentioned by @3dcad, if we cannot do this, but have to rely on importing all the patterned parts from the PS into the assembly, we have this problem :
     a single part (say a wheel on a car) becomes four parts in an assembly (and any BoM based on that assembly), instead of remaining four instances of the same part.
  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,475 PRO
    At current stage I'm bit confused if Onshape is pushing us to build all static stuff in ps and only motion in asm? Or are they going in direction where parts are built in ps but asm is The place for final design?

    I would prefer having more assembly tools and automation for derived parts in ps rather than forcing everything going through assembly.
    But if there is going to be assembly patterns and other stuff like that, drawings + bom support only for assy and no enhancements to derived parts then it would push us towards 'traditional' style.

    I'm thinking the time after cross document references and other standard features are implemented and beta testing finished ie. normal workflow in future when Onshape is real alternative to SolidWorks and others.

    It would be very nice if we could build static models in ps and easily derive standard parts in and use the model in drawings etc. without forcing to create assembly if it only makes updating difficult without any benefits.
    To be honest I would like to even derive subassemblies with motion into ps and make ps being the place for finished model; assembly mode would be just for creating motion between parts. What do you think of this?
    //rami
  • joris_kofmanjoris_kofman Member Posts: 59 ✭✭
    3dcad said:
    It would be very nice if we could build static models in ps and easily derive standard parts in and use the model in drawings etc. without forcing to create assembly if it only makes updating difficult without any benefits.
    To be honest I would like to even derive subassemblies with motion into ps and make ps being the place for finished model; assembly mode would be just for creating motion between parts. What do you think of this?
    You read my mind. For some designs assemblies add no real functionality, so we should be able to go directly from PS to drawing. But we may need to be able to specify a subset of the parts to be on each sheet in a easy way.
    And we need the ability to place bolts, washers etc so we can complete the designs and create bills of materials.

    I think in some cases you would need to go back into a part studio to create a part that relates to an assembly with motion in it.


  • andrew_troupandrew_troup Member, Mentor Posts: 1,584 ✭✭✭✭✭
    edited November 2015
    @3dcad : interesting idea, to demote/degrade assemblies to purely an editing interface, and have what's currently called "Part Studio" be effectively the place where models begin and end, perhaps a "Modelling Studio". There are many obvious advantages.

    If we follow where that leads : I wonder if there's any remaining merit in assembly being a separate tab :
    as other forum participants (starting, IIRC, with @billy) have suggested, it might be better to do EVERYTHING in the PS.

    I have resisted the idea up till now, (and I still would want to see a modal switch between "Part Modelling" and "Motion Control" modes), but I'm gradually warming to it.  
    My main concern remains this: when parts have entities whose location is projected from other parts, how does this work when there is relative motion?

    And to give a possible answer to my own question: in the aforementioned bi-Modal  Modelling Studio, when in "Part Modelling" mode, all parts would revert to the positions in which they were statically modelled, and all interpart relations would reflect that static relativity. Switching to "Motion Control" mode, the parts would snap to where they were last left when previously working in that mode.
  • _Ðave__Ðave_ Member, Developers Posts: 712 ✭✭✭✭
    Kudo to you all, this sounds brilliant if not genius. But I don't think the old school SW guys will approve. I suppose for them they could always have an assembly tab if they desire.
  • brucebartlettbrucebartlett Member, OS Professional, Mentor, User Group Leader Posts: 2,140 PRO
    Just been working on one of my designs, which I am getting ready for production, I have structured with the intent of having full BOM's and complete drawings. In this doc I have the main part studio, in here are all my construction sketches and parts linked together, I have chosen not to do any patterning of mirroring but where parts are repeated just leave the space blank, in some cases the sketch tells the story of what is missing. Out of this main part studio I then build 5 or 6 sub assemblies (all rigid weldments) from the parts in the main part studio as well as other imported parts/stand alone parts, then add the sub-assemblies (some multiple times) to my top assembly which has also motion.

    In this case I would not want to use the part studio at all for my drawings or BOM's, but act as my my design area to build and link parts together. In this project the main thing I was missing (apart from complete Drawings and BOM's) was the ability to configure my top assembly into different finished product variants and lock motion to a rigid position for my drawing. 
    Engineer ı Product Designer ı Onshape Consulting Partner
    Twitter: @onshapetricks  & @babart1977   
  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,475 PRO
    @3dcad : interesting idea, to demote/degrade assemblies to purely an editing interface, and have what's currently called "Part Studio" be effectively the place where models begin and end, perhaps a "Modelling Studio". There are many obvious advantages.
    ...
    .. in the aforementioned bi-Modal  Modelling Studio, when in "Part Modelling" mode, all parts would revert to the positions in which they were statically modelled, and all interpart relations would reflect that static relativity. Switching to "Motion Control" mode, the parts would snap to where they were last left when previously working in that mode.
    Exactly! I think you see the same light that I saw when I first read @billy 's thoughts about combining part&assembly studios.
    Before that I didn't have courage to even think different workflow than traditional mcad way and all I could suggest was to make that way work better (patterns in assembly).

    DaVicki said:
    Kudo to you all, this sounds brilliant if not genius. But I don't think the old school SW guys will approve. I suppose for them they could always have an assembly tab if they desire.

    I'm sure Onshape has prepared to be a game changer in many areas and this would be a huge step forward if they could make if work flawlessly. 
    --

    @scott_harris;
    Can we get any comments from Onshape?

    //rami
  • scott_harrisscott_harris Moderator, Onshape Employees, csevp Posts: 66
    Great discussion guys. We debated this very issue for months when first architecting Onshape and the idea of the unified part studio/assembly has merit. We chose to make part studios completely deterministic so it would never fail to generate the parts defined by the parametric features.  Each part studio has one parametric history and the part studio defines the shapes of the parts.   The assembly was designed to take parts generated by part studios and constrain them variationally, giving both motion and more importantly positions that can not be easily modeled parametrically.   It also is designed to scale to very large assemblies, have structure (sub-assemblies), instancing, and motion.    By separating the two (I know it seems old school), we have built in robustness.   

    As we expand the system to support linked documents and editing part studios in the assembly context, the strength of this architecture will become even more clear.   Editing in assembly context has been a major problem in traditional cad systems, because inherently the parametric histories of the parts and the assemblies are intertwined but not synchronized, and this is not robust.

    With respect to patterns, we totally get it and are adding capabilities which will solve the instantiation issues as quickly as possible.

    /Scott
    Scott Harris / Onshape, Inc.
  • brucebartlettbrucebartlett Member, OS Professional, Mentor, User Group Leader Posts: 2,140 PRO
    Thanks @scott_harris for the insights. As I build more stuff in Onshape, I really do think you have got it right with Part Studio and Assemblies. I've just done a fabricated product main parts designed and linked in 1 part studio and then split up into different rigid sub assy's and the a top flexible assy. This gives great flexibility to supply assy's/drawings for specific component of the design and change the structure without things falling part. I'm really enjoying the results, you just have to get your head around the way Onshape work's respect to multi-body design (keep as much as you can in the main part studio), assembly with groups mates and inherently flexible sub assemblies.

    Engineer ı Product Designer ı Onshape Consulting Partner
    Twitter: @onshapetricks  & @babart1977   
  • 3dcad3dcad Member, OS Professional, Mentor Posts: 2,475 PRO
    @scott_harris
    Thanks for taking time to comment. I knew this must have been discussed and that there has been something why you didn't go with only one workspace. It is good to know where the ship is going so we can put in the requests that support 'the bigger plan' (like asm patterns).
    Robust is exactly what we need and if it needs separate assemblies - then we just push you making it awesome.

    Looking forward to future updates!
    //rami
  • andrew_troupandrew_troup Member, Mentor Posts: 1,584 ✭✭✭✭✭
    @scott_harris
    Thanks for such a clear and informative laying out of the issues. 
    I'm easily persuaded to re-invigorate my preference, up until now, for the separate PS and Assembly paradigm

    ...  but even for someone who wasn't, I do think the points you raise are (objectively) persuasive.
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