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Sketches and Points confusion

ts_2ts_2 Member Posts: 22
I'm trying to made a sketch with a bunch of dimensions.  After a bunch of working on it and getting it to work.  My sketch looks enclosed... but it does not appear shaded as a solid sketch.   How can I weld the points?    If I attempt to move my entire sketch by selecting all,, upon moving, lines start breaking apart showing me not all edges are connected.  
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Answers

  • colemancoleman OS Professional Posts: 242 PRO
    @Ts  can you make this a public document and provide a link so forum members can take a closer look?  Screenshots are great but the power of OS is making your document public so the community can help!   
  • brucebartlettbrucebartlett Member, OS Professional, Mentor, User Group Leader Posts: 2,037 PRO
    edited May 2015
    Don't know if this will help, but you can show all the constraints by checking the show constraints check box on the sketch dialogue. 
    Engineer ı Product Designer ı Onshape Consulting Partner
    Twitter: @onshapetricks  & @babart1977   
  • ts_2ts_2 Member Posts: 22
    I've sort of trashed my scene and the dimensions to create the sketch.  I'm a noob at cad modeling.  Once All my dimensions where set, I deleted them because they were just a headache.  I know I'm not doing everything correctly. but  Now all my lines are just separate segment lines, and while Its workable, I've Hosed the ability to control anything.  I can't move the whole sketch without things flying apart.  Feels like some kind of bug.  It would be nice to actually WELD points to other points.   

    It would be nice if I could just create a brand new sketch, while using my Hosed one as a reference, allowing me to snap points and things to other sketches in the background and retrace the whole thing.
  • ts_2ts_2 Member Posts: 22
    I made my file public, its a Lightsaber handle.   The confusing part is.  I made a bunch of random Dimensions to keep things from flying apart.  Some make no sense.   But the root problem is still that most of the edges in the sketch of handle of the lightsaber aren;t really connected to each other.   I really wish I could select all vertex, and just weld them, so they move as a contiguous shape  

    https://cad.onshape.com/documents/5b28f02b27d04b67b1c31d16/w/bccca3dd219f489992ed1adc/e/053a891fe7a14738baf40c60

  • traveler_hauptmantraveler_hauptman Member, OS Professional, Mentor, Developers Posts: 419 PRO
    @Ts With this type of cad a math solver is used to determine what the user intends the sketch to mean and how to use it for creating other geometry.

    The quick way to say it is that the solver is allowed to move any sketch geometry unless you specifically tell it something else. You tell the sketch solver what you want to do using constraints. Dimensions are one of the constraints and must be left in, even if it makes the sketch visually difficult to understand, so that the solver knows what you want to do.

    There is a way to weld the endpoints of segments together and in fact it is one of the most often used constraints.

    This  this help page gives you a starting place to learn about this type of CAD modeling in general.

    This help page has some info specifically on constraints.

    Time spent on tutorials is well spent. 
  • r_paulr_paul Member Posts: 22 ✭✭
    edited May 2015
    @Ts 

    I have made a copy of your Public file and in doing so have found the problem your sketch is presenting has a lot to do with the fact your sketch, particularly the "v" grooves, had no Coincident constraints applied.  It's a matter of technique, you will become better at with practice.  This issue is readily fixed by selecting the points and then selecting the Coincident constraint from the menu.

    With you job I first turned on the Origin and constrained the vertical "centre" line to it and dimensioned it vertically as well.  Next I constrained the lines which defined the "v" grooves to be equal in size and their top and root points I also constrained to be vertically inline.

    The very top line also needed to be constrained Horizontally.

    Then to fully constrain the sketch I placed the additional dimensions.

    One little comment here the Coincident constraint is analogous to your "welding the point together" comment.  That's exactly what it does; joins points (and other geometry) together so they behave as one.

    In the new Part Studio in the linked public document below you can see the end result;

    https://cad.onshape.com/documents/8da798d6fb454fbf94f2ec30/w/d1ee762ea675479bb9acb93b/e/7451af7dec6a44c79a18e195

    Traveler_Hauptman has provided it will help.

    Yell out if you want to know more.....
  • ts_2ts_2 Member Posts: 22
    Thanks much guys for the help and tips.  I'll have to digest some of this slowly and keep practicing.
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