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mid-plane mate

andre_brown101andre_brown101 Member Posts: 8
I have 2 parts in a subassembly.  they are symmetrically arranged and offset from the origin (forming a center plane) - I have placed a mate connector at its origin.  the parts are cylindrical in general form.
the 2 part subassembly is inserted into a top level assembly, and the cylindrical form of one part is mated to a housing part in the top level assembly via a cylindrical mate between the faces of the parts.  this works fine.
I need to mate the center plane (the mid point between the two cylindrical parts) to the origin mate connector in the top level assembly to position the subassmbly left-right.  however when I do a planar mate it constrains the wrong pair of axis (xy instead of xz) and then proceeds to break the cylindrical mate.
I am going crazy.  why can't I just mate planes in an assembly environment?  or at very least why can't I chose which pair of axis to use for the planar mate using mate connectors?


  • Options
    S1monS1mon Member Posts: 2,492 PRO
    Onshape's approach to mating and assemblies definitely takes some time to get used to. Once you do, you'll find that it's generally much more efficient than in say Creo or Solidworks. Things that take 3 mates in other systems will typically only take one in Onshape.

    The lack of assembly planes does sometimes seem like a huge mistake, but what you can do is add a mate connector in the assembly at the origin. When you create that, you can choose which axis is the primary axis of the MC. Depending on your assembly, picking X, Y or Z may make more sense. 

    Fix and Group mates are ok, but they are hard to repair if you accidentally move something out of position. I prefer to explicitly mate things to the origin MC as much as possible, or use functional mates (e.g. screw into screw hole) when appropriate. I also sometimes create "skeleton" sketches in master model part studio which I put in the assembly in order to hang parts off of that if it doesn't make sense to use the origin or a functional mate. 

    I highly recommend going through the training material in the learning center.

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