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Fancy Constraints?

ryan_henningryan_henning Member Posts: 6
edited February 2016 in Using Onshape
There are a few constraints I'd like to be able to add. Perhaps it's already possible and I just don't know how! Will you all help me? (I'm new to CAD, so this is all new to me. But I'm having a great time building my model in OnShape!)

1. I'd like to be able to set the diameter of a circle equal to the length of a line.
2. I'd like to be able to set the length of a line equal to some ratio of the length of another line. E.g. Line 1 is always half the length of Line 2.
3. Combining the two above. I'd like to set the diameter of a circle equal to some ratio of the length of another line.

Are those things possible? Thanks!


  • Options
    3dcad3dcad Member, OS Professional, Mentor Posts: 2,470 PRO
    1. Draw construct line inside circle and set that line equal to other lines
    2. Create variable before sketch and set line1 lenght = #var_linelenght, line2 lenght = #var_linelenght / 2
    3. Just use variable as value for diameter

  • Options
    ryan_henningryan_henning Member Posts: 6

    Thanks! Variables, that makes sense.
  • Options
    NeilCookeNeilCooke Moderator, Onshape Employees Posts: 5,441
    if you wanted to get half the length of the line without using variables you could sketch a construction line from the endpoint to the midpoint of the line then use an equal constraint on that. To get a third of the length, draw three end to end construction lines, set them equal length, and connect the ends of the chain to the endpoints of your original line.
    Senior Director, Technical Services, EMEAI
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