Sketch constraint is broken

Sketch constraint is broken

Anonymous
Not applicable
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Message 1 of 9

Sketch constraint is broken

Anonymous
Not applicable

Hi,

I encountered a trouble of sketch.

Please look at the following Youtube.

 

http://youtu.be/aJ1hkaUanY0

 

Is there a workaround?

Thanks,

KG.

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973 Views
8 Replies
Replies (8)
Message 2 of 9

promm
Alumni
Alumni

Aaa_sekkei,

 

After reviewing your video I tried to reproduce and I am getting different results.  Please try two different workflows for me and let me know if you still have the same results.

1. Constrain the circle to the center of the origin, then add the radius dimension to the Arc.

Arc Dim.png

 

 

2.  Instead of drawing the Arc past the circle then trimming, start on the circle for your first point.  If a tangent constraint is needed add after the Arc is created.

 

Arc Dim 2.png

 

Cheers,

 

Mike Prom

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Message 3 of 9

Anonymous
Not applicable

Hi Mike,

Thank you for your reply.

 

Your figure is seems to center of the two arcs do not match.(It is a groove for guiding the pin)

I need that the two center are the same position.

When the arc center is matched, constraint is broken by parameter change again.

 

For this reason, I think that without a fragile sketch, use a Boolean cut by robust model.

I hope that the sketch is robust.

 

Thank you.

KG.

 

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Message 4 of 9

Anonymous
Not applicable

My colleagues have created in Inevntor.
That can be perfectly controlled by parameters.

 

Thanks,

 

KG.

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Message 5 of 9

schneik-adsk
Community Manager
Community Manager

Here is one approach that works while we look at the error.  I used a construction line to control the distance using a linear aligned dimension.

 

sketchexample.png

 

 

Kevin Schneider
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Message 6 of 9

sanjay_jayabal
Autodesk
Autodesk

Hi,

 

Here is what I did. If this reflects what you are trying to do, I am happy to post my Fusion file.

 

1. Create a circle.

2. Create 3-point Arc starting from a point on the circle.

3. Create a tangent constraint between the arc and the circle.

4. Create a center-point arc as you did in your video (same center as the first arc and starting point of the arc from the center of the circle).

5. Add the dimension to both arcs.

6. Modifying their dimensions, properly resized the circle.  (Note: I did notice that changing the dimension of the outer arc updated the circle size only every other time.  That is, the size didn't refresh on the screen visually until the dim was changed again.  However, my geometric constraints were maintained and didn't break)

 

best regards,

Sanjay Jayabal.

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Message 7 of 9

sanjay_jayabal
Autodesk
Autodesk

One other thing I did to workaround the visual refresh problem (that makes it look like the constraint is broken) is to trim the circle to a semi-circle.  Hope this helps.

 

Screen Shot 2015-06-29 at 1.03.53 PM.png

 

Best regards,

Sanjay Jayabal.

Message 8 of 9

Anonymous
Not applicable

Hi Kevin,

 

Thank you for your good idea.

I seems 

 

Thank you.

 

KG.

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Message 9 of 9

Anonymous
Not applicable

Hi Sanjay,

 

Thank you for your good idea.

I can draw a good sketch by using some of the ideas.

 

Thank you.

 

KG.

 

 

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