Having a difficult time Constraining 2D sketches.

[Anonymous]

Also, I'm having a hard time completely constraining copy 2D sketches.  Can someone give me an insight on what Inventor requires to constrain a 2D sketch?

Thank you.

[Anonymous]

I added an example,  one of my issues.  If you notice the angle cut on the back side, when you go to edit sketch, the sketch is not completely "blue", or fully constrained.  What do I need to do?

Thanks.

[JDMather]

While in sketch right click and select Show all Degrees of Freedom.

This shows that you need to add 2 coincident constraints between the line shown in this image on the right and the projected vertical line or 1 coincident and 1 vertical.
These constraints should have been added automatically by Inventor when you sketched (and actually the sketched lines aren't needed - but I would probalby add them as you did, and also - you could have used a Chamfer with no sketch)

[Anonymous]

Ok, great that helps alot.  That's what I thought about, Inventor should have done.   But it still shows one degree of freedom in the top left corner, by the .300 dimension.  I'm not able to more the line in any direction.  Also, how did you insert the pic?

Thanks.

[JDMather]

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@Anonymous wrote:

....  But it still shows one degree of freedom in the top left corner, by the .300 dimension. Thanks.

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Attach the file here.

[Anonymous]

Well, I deleted all of the lines, and started over.  And now everything appears to be Ok.  Here is the model.

Thanks.

[Anonymous]

Ok, having another issue, how do I fully constrain a circle to the origin?   I thought if I selected the origin for my starting point, and dimension the od, it would be fully defined.

Thanks.

[JDMather]

Is your origin Center Point projected into the sketch (should be automatic if Inventor is set up correctly.

Attach your file here.

read this

http://home.pct.edu/~jmather/skillsusa%20university.pdf

[Anonymous]

Here's the file, it's very basic, for now.

Thanks.

[JDMather]

Uhmm the circle is not at the origin?

Drag the center of the circle to the green dot to the lower right of the circle.

This is the projected origin center point.

I recommend that as a beginner you go to the Origin folder in the browser.
Expand the origin folder.

Right click on Center  Point and select Visibility.

[Anonymous]

I left the circle off of the origin for a reason.   Even when I chose the origin for my start point, and after I dimension the circle, it will stay green.   I also have the origin visibility, I just don't understand why I'm having issues.

Thanks.

[JDMather]

Attach the file here.

[Anonymous]

Here we go.

Thanks.

[JDMather]

Somehow you got the center of the circle directly over the origin without constraining it.
Click and drag is not selecting the circle center - but is selecting the projected point, which of course won't move.
Simply add a coincident constraint and click there twice.

As you get more familiar with sketching this won't happen - it will automatically constrain.

[Anonymous]

Got it, Thanks again.  I've noticed that alot of things are not automaticly constraining, as for solidworks would.  Also, I tried adding a coincident constrain, but I was choosing the outside diameter, and not the center of the circle. 

Thanks.

[JDMather]

SWx will cross-sketch constrain without projecting geometry.

There is a way to set Inventor to "sort of" do this - but I don't like the way it works, so just get used to having to Project Geometry from one sketch to another.

As much as possible (or practical) tie your sketches to the origin rather than to existing geometry (in Inventor or SolidWorks).