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Mating failure

morgan_maymorgan_may Member Posts: 4

Apologies if this is a repost of my same question. My wifi cut out and I'm not sure if it posted or not

I'm having issues mating parts together. When mating cylinders to cylinders or planes to planes in the above assembly, the base part features don't seem to be selectable. The two additional parts seem to be able to mate together just fine, but I can't get anything to select from the largest segment. 

I'm assuming I'm doing something wrong or there's an easy fix, but I can't seem to find anything online that looks related to my issue.

In the larger main part, there are a lot of fairly complex features being used, I had to split and then merge a few bodies, lots or mirrored and revolved features. I'm hoping those aren't the issues as I couldn't see any other way to make the parts, but any help or support on this would be greatly appreciated. (the final build will be epic)


  • john_mcclaryjohn_mcclary Member, Developers Posts: 3,636 PRO
    I'm not sure what your issue is, it appears to be mated to me.

    By base features do you mean the construction planes?
    Onshape does not read into the part studio and grab construction geometry. Like default planes, axis, sketches, etc. Unless you explicitly create or import them into the assembly, by using mate connectors, sketches, etc. So, you will need to create the construction geometry in the part studio and associate it with the part (in the case of a mate connector) in order for it to a appear in the assembly.

    How you construct geometry in Onshape is irrelevant. When a part is imported into another part studio or assembly, it is treated no differently than a dumb solid you may have imported from another CAD system. Which makes all parts behave the same no matter where they were sourced, or what method was used to create them. The only real exception to that is the additional properties that are gained by using the "Hole" feature for calling out screw threads in drawings.
  • eric_pestyeric_pesty Member Posts: 220 PRO
    I would really recommend you look at some of the training on assemblies and mating as Onshape is different works differently from other CAD systems in this respect and it would make your life a lot easier...

    It would make things simpler if you added a couple explicit mate connectors in the part studio but here's how you can mate this with way fewer mates:


    Note, the "wheel slice" part isn't shared (only with a link) so I can't have it in the copy I made but it would basically just need one fasten mate to the fixed part (or it could itself be fixed and the two top parts mated to it.

    Another comment I would add is that it would be a lot easier to design something like this if these different parts were designed in a single part studio!
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