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Flowing Tutorial and tangent constraint issue

allen_stewart
allen_stewart Member Posts: 32 ✭
in Community Support

Hello All,

I am new to Onshape and Im following the text tutorial and I am having a little problem with the tangent constraint feature.

I have the large circle connect to the small circle using two lines.  As soon as I add the tangent constraints (like the tutorial shows) both circles become the same size.  Im guessing im doing something wrong but Im following the tutorial exactly step by step.

https://cad.onshape.com/help/#tutorial-sketch.htm%3FTocPath%3DTutorial%7C_____2

Thank you

Best Answer

Answers

  • rbaek
    rbaek Moderator, Onshape Employees, Developers Posts: 77 image
    allen_stewart said:

    Hello All,

    I am new to Onshape and Im following the text tutorial and I am having a little problem with the tangent constraint feature.

    I have the large circle connect to the small circle using two lines.  As soon as I add the tangent constraints (like the tutorial shows) both circles become the same size.  Im guessing im doing something wrong but Im following the tutorial exactly step by step.

    https://cad.onshape.com/help/#tutorial-sketch.htm%3FTocPath%3DTutorial%7C_____2

    Thank you

    Are either of the circles dimensioned/constrained already? I'm guessing what's happening is that since you haven't dimensioned or constrained either, applying the tangent constraint is trying to resize the circles to make the sketch solvable. Are there any other sketch entities in the same sketch, or are you only working with two circles?
  • allen_stewart
    allen_stewart Member Posts: 32 ✭
    Only working with the two circles and lines.  I was following the tutorial line by line and ran into this problem.  I will give your suggestion a try.  Thank you
  • allen_stewart
    allen_stewart Member Posts: 32 ✭
    thanks guys
  • andrew_troup
    andrew_troup Member, Mentor Posts: 1,585 ✭✭✭✭✭
    edited June 2015
    My first thought is that the lines might be constrained without you knowing it: perhaps both are horizontal, or they are parallel to each other. 
    In either case, establishing tangency with two circles would then force those circles to be the same diameter.

    To find out if they're constrained, edit the sketch, and tick the box for "show constraints"
  • matthew_mucker
    matthew_mucker Member Posts: 7 ✭✭
    I ran into the same problem. It's not a good sign when the beginner's tutorial doesn't work when followed step-by-step.

    Going through the tutorial a third time and dimensioning the circles first appears to work.

    Looks to me like the tutorial needs to be updated.
  • johan_blohm
    johan_blohm Member Posts: 2 ✭
    This is a very old thread but I'm running into the same problem when following the tutorial "5. Sketch Tools: Intermediate Sketching. I have tried to go back from scratch several times following the tutorial to the letter but the instructions doesn't add upp leaving you with an incomplete drawing. VERY frustrating!

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