Lots of issues with V25

Hoogmolen
Hoogmolen
in 3D Modeling

I'm unable to subtract or use union command in a particular drawing. Tgis drawing consist of a screw thread made by using helix and sweep. but unable to subtract or union the thread to a solid. Also i found out when using arraypolar within a solid object to subtract it does not allow to subtract the induvidual items from that solid(after exploding the array)

attached is the drawing with the issue. i'm trying to use the union command on the threads to stitch it to the solid. i tried the other way around aswel bij the command subtract but that does not work either in V24 and V25

Union Issue.dwg

Comments

  • Virgil
    Virgil

    Hello.

    Creating a continuous sweep like this leads to a 3D solid with some self-overlapping edges.
    This is not working, especially with ACIS kernel.

    An alternative is to create the thread from sevelar smaller solids and use UNION to join them into the final thread.

    In the end, the thread can be joined with the main part.
    See the attached drawing.

    Even in this case, when using DMAUDIT, there could be some modelling errors reported.

    You could also experiment with using a thread height smaller than the pitch, and see which approach is better for you.

    Union mod.dwg

  • Hoogmolen
    Hoogmolen

    Hello virgil, how would you make threads on a 3dmodel than, seems to me this should be a basic command fo a mechanical designer. i've tried the way you described but that way to intensive if i would need to design a special threaded bar or something like it. I used to work with autocad and ther this was not an issue.

  • Virgil
    Virgil

    Hello.

    In my testing, Autocad 2025 also failed to union the 2 solids.

    So, because solids with self overlapping edges are not useful, the first approach seems to be a solution for cases when the height of the profile is equal to the pitch of the thread.

    Another way of working would be like the second approach mentioned previously.

    When the height of the profile is smaller that the pitch, then the helix solid can be modeled in one piece.
    In this case, the procedure is somewhat faster than in the first case.

    I attached a model with this second approach.

    Union mod_2.dwg