Intersection curve not updating on 3d sketch

[chipwitch]

Seems like an odd behavior to me... just looking for confirmation that Inventor should be able to do the following:

Two intersecting surfaces are used to project a line onto a 3d sketch using the "intersection curve" tool.  The curve is created successfully and indicates it is constrained to the underlying surface being projected as expected.  However, when the surface being projected is moved relative to the surface being projected to, the curve in the 3d sketch remains in the same position relative to the part's coordinate system.  Consider that the two surfaces are normal and remain normal to one another even after the projected surface is being shifted.  Ie the projected surface is being shifted parallel to the surface being projected to.

This is a part file.  Single body with 3 surfaces. Inventor Pro, 2015.  No errors are being thrown.

[chipwitch]

Attached is the file in question.  "3D Sketch7" near the bottom of the component list.  The problem occurs when I attempt to move "Srfc5" in the Z direction 1mm.

[johnsonshiue]

Hi! The file was created in 2015 and last saved in 2015. There is something interesting with 3D Sketch7. Although the project constraints exist in the curves, there is no source geometry the sketch curves are associated with. Do you know how to reproduce this behavior? The curves are not intersection curves. They would have an Intersection Curve node in the 3D Sketch. I suggest you delete the curves and recreate the Intersection Curve.

Please let me know if you can reproduce the behavior.

Many thanks!

[kelly.young]

@chipwitch it appears Sketch4, Sketch13 each have a sick point. Sketch4, 13, 14, 17 are under constrained. 

If you are going to make parts that are parametric to stretch to any size, make sure that it is Fully Constrained so that it won't break when trying to change dimensions. 

It appears that Srf5 height is controlled by Sketch 14 & 17 which are not linked to each other, nor fully defined.

So in Sketch14 if you want to change dimension d58 it won't reflect into Sketch17 as it's not constrained to any Projected Geometry.

I would go back through, tighten up all dimensions in the 2D Sketches and define everything to reasonable numbers.

For example 32.0220657 deg will be problematic in any manufacturing method.

It's not clear if that addressed your question, but would advise fixing that stuff and maybe create a screencast showing how the part is behaving badly.

Please select the Accept as Solution button if a post solves your issue or answers your question.

[chipwitch]

Hi and thanks for the reply.

Where do you see the file was created and last save in 2015?  It wasn't.  I only created it a couple days ago.  As for the geometry.  It most certainly IS there!  It is two of the surfaces.  One of them may have been moved 1mm in the z-axis.  I'm not sure if I had raised it yet in the file I attached, but it might be up 1mm. 

I explained how I created it.  It was pretty simple.  I created the two surfaces, then created a new 3d sketch.  I simply clicked on the "curves intersections" icon on the ribbon.  That's it.  Trying to move the surface resulted in the created curve NOT updating, prompting the OP.

[chipwitch]

Hi Kelly. Thanks.  I think you might be onto it.  I'm not at my workstation at the moment.  I'll check your suggestions in the morning and respond back.

ETA: Also, why would there be a "sick" point and the doctor not raise the issue?  I've actually had that occur quite a few times lately.  I wasn't aware there was still one in the part.  Could it be because the part was created as part of an assembly?  Some of the geometry like work planes would have been created from other parts in the assembly.

[kelly.young]

@chipwitch if a projected point has its link broken, the point reference can break making it pink (sick).

I don't know why the doctor doesn't get angry but probably because it has no affect on the model or dimensions in the sketch, it is just a disassociated point in no man's land with no dependent dimensions going to it. Probably a better explanation that this.

If you are referencing other parts and planes, are you creating adaptive parts and then breaking the links?

I admittedly do this but only to get prototype designs, not robust parametric models as it is easy to leave remnants of bad geometry like this.

Do you ever use Derive to reference other parts?

Just trying to find out the workflow and how you're ending up with the sick points.

Please select the Accept as Solution button if a post solves your issue or answers your question.

[johnsonshiue]

Hi Sherri,

I am sorry for my poor grammar. I meant the file was created and saved on Inventor 2015, not in the year of 2015. The 3D Sketch 7 seems to be corrupted. Like I mentioned earlier, there should be a browser node for 3D Intersection Curve but within 3D Sketch 7 there was no browser node. I am trying to figure out how to reproduce the behavior. Could you delete the 3D Sketch 7 and then repeat the workflow you did before? Does it still not update?

Many thanks!