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Grouping sketch elements

Discussion in 'Using Alibre Design' started by salex319, Sep 10, 2019.

  1. salex319

    salex319 Member

    Newbie using Atom3D 2019. I'm completely mystified about how to move multiple elements in a 2D sketch. I've seen tutorials where you simply select multiple elements, two circles for example, and then click on one and they both move together. That doesn't work for me. In the image below I drew two "objects." Before adding the dimensions if I selected all the elements in one of the objects and tried to drag it somewhere it would simply move a single element of the object thus changing the object. Yet when I added the dimension on the one on the left I am able to move the entire object up and down. Likewise the object on the right couldn't be dragged anywhere as a whole. And when I added the dimension it's being constrained by something and I don't know what. I can't change the 14 to anything else. These objects are extruded fine too so they seem to be properly closed objects. What am I missing?

    upload_2019-9-10_12-58-51.png
     
  2. Lew_Merrick

    Lew_Merrick Alibre Super User

    I may well be (way) out of line here as I know nothing about Atom3D, but my guess is that you need to Constrain things to get them to Move together.
     
  3. salex319

    salex319 Member

    It may be that a variety of constraints may be necessary to keep elements properly related when moving an object but I hope not since figuring out which constraints are necessary could be very time consuming. I experimented with constraints with that in mind but couldn't figure out what combination would work. Also the element on the right has no constraints but I can't move it vertically by changing the indicated dimension. There's apparently an implied constraint of some kind. In any case I was hoping someone who knows might reply so that I could stop guessing.
     
  4. oldfox

    oldfox Alibre Super User

    Dimensions ARE constraints. Are you grabbing the circle with your mouse or the center dot of the circle? I think that if you 'select all' and grab
    the dot, the entire thing can be moved to your pleasure, without constraints.
     
  5. salex319

    salex319 Member

    I thought that what you say is how things are supposed to work. But if I start with a new design and draw a rectangle which I then extrude to some depth. Then on the surface of that object I draw a circle and intersecting rectangle. Then I trim the interior lines. If I select that entire object and then click on the center of the circle and try to move the object only the circle moves. Or if I click on a line only the line moves. I can however then dimension the center of the circle to an edge or something and move the entire object around. It's frustrating because I watch tutorials and see things done which I can't do. Perhaps someone can confirm that Atom3D simply works differently - if that's the case.
     
  6. idslk

    idslk Alibre Super User

    Hello salex319,
    that means you have not constraint the line to the other elements of the figure.
    Each element of a figure like your "keyhole", has to have certain positions to each other.
    This is done with constraints.
    If the circle in your sample "knows" where he is located in respect to the line you want to move, he will move accordingly.
    The following picture shows a "keyhole" with referencelines and constraints. This keyhole can be moved completely by dragging it with the mouse. If you add an dimension for the distance of a circle to the X-Axis, you will have left only the freedom to move the elements along the Y-Axis...
    upload_2019-9-11_9-32-11.png
    upload_2019-9-11_9-43-4.png

    If the distances of the sketch to the coordinate system are constrain, the sketch elements will change the color to show you that the sketch is now fully constrained.

    The appended file is not made with Atom3D. Hopefully you can read and edit it.

    Regards
    Stefan
     

    Attached Files:

  7. Max

    Max Administrator Staff Member

    How to move figures together
    If you want to lasso select multiple items and move them together, assuming constraints and dimensions will allow it, hold down the SHIFT key while you drag the figures around. If you do not hold down SHIFT, your drag action will only affect the figure you are actually clicking on, versus the group.

    In some cases, dimensions and constraints you have placed may give the same effect, even if you only drag one figure - if the other figures are constrained to it, they may well follow it around.

    Driving vs. Driven dims
    Regarding your "I can't edit the 14", dimensions in (14) parenthesis are "driven dimensions" meaning that the value of the dimension has already been defined, perhaps through constraints. You can't define the same thing twice - so driven dimensions merely show you what the value is, but they are not editable. Think of them as a realtime distance/angle update. You'll also notice that driven dimensions can and will change on their own when you make changes to the model.

    Simple example:
    We've created 3 lines. We've set up a Horizontal constraint between the end nodes of lines A and B. As a result, they will move vertically together.

    Now, when we dimension line A to line 1, we've defined the distance for not only line A but also, through our constraint, for line B. If we try to make a dimension between line B and Line 1, that dimension really already exists. As a result, a Driven Dimension will be created instead, which cannot be edited, but which does allow you to view the current value. If you change the dim between line A and line 1, line B's driven dimension will update. To actually change line B's offset from line 1, you would need to delete the horizontal constraints between the nodes of A and B, and then delete the driven dimension - now you can place a real dimension.

    upload_2019-9-11_5-39-29.png

    Bonus Tip
    When you end a figure on another figure, for example you end a line on the endpoint of another line, an invisible coincident constraint is created. 99% of the time, this is what you want. But sometimes you may want to break it. To do this, Select Tool > hold down CTRL > select and drag the node - you will break apart the 2 connected lines.

    In your case, perhaps the (14) dimension is Driven because the midpoint of that keyway is actually on the origin, and you might need to "break it off" using this method so it is free to move about.
     
    Last edited: Sep 11, 2019
  8. salex319

    salex319 Member

    Thank you all for your inputs. Thanks especially to Max who solved the primary question in the first paragraph with the magic word "shift." The shift key to drag multiple items is what I didn't know and it works beautifully.
     

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