Projected Geometry on Feature Creation

[Anonymous]

This has happened to me a few times so I thought I would reach out and ask about it. However, I do not have an example ready and waiting for whomever may decide to help. Nevertheless, here's the problem:

Every now and then, I'll create a sketch on the face of an object and I have my settings such that inventor will autoproject the edges of the object face. So let's just say, for example, that I'm adding material around the outside of the object for whatever reason. My first inclination would likely be to create a close profile that extends from the edges of the object using the projected lines as one or more of my bounding edges (I've attached an image of this to make my visual clear).

On occasion, when I go to extrude that profile, inventor will show that there is no closed profile. Additionally, it will sometimes not show some of the projected edges once the feature command is activated. So when I'm in the sketch, the projected edges are there, but as soon as I hit extrude, a number of them may disappear and I will not have the profile I want.

Anyone else run in to this? I'm certain it's a bug but I'm wondering if there is a way to fix it. Any ideas?

Thanks,

[blair]

Double check your Inventor Application Options>Sketch>Auto Project on sketch creation is not turned on.

[Anonymous]

@Anonymous wrote:
Double check your Inventor Application Options>Sketch>Auto Project on sketch creation is not turned on.

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Don't I want that turned on?

My issue is that some of the projected lines vanish when I attempt an extrude. And when they do, it is often edges I need as a boundary for my profile.

[blair]

I generally leave the Auto-Project turned off, If I want something projected I will then use the Project Geometry.

[Anonymous]

I can get behind that. I generally don't create sketches on geometric faces. I typically keep it to origin planes if I can. However, I still feel this function should work for the few occasions in which I use it. And I'm still baffled that the lines will appear in the sketch but not in the feature.

[johnsonshiue]

Hi! I have heard similar complaints before. The behavior is indeed constrolled by Application Options -> Sketch -> Autoproject edges for sketch creation and editing. When the option is checked, the projected edges of the selected face will always be there on sketch creation or editing. If it is off, any unreferenced or unconsumed auto-projected edges will disappear. It is because Inventor assumes these projected edges are not needed. The exception here is if you manually project the edges or the loop, the projected edges/loop should stay.

Thanks!

[Anonymous]

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@johnsonshiue wrote:

Hi! I have heard similar complaints before. The behavior is indeed constrolled by Application Options -> Sketch -> Autoproject edges for sketch creation and editing. When the option is checked, the projected edges of the selected face will always be there on sketch creation or editing. If it is off, any unreferenced or unconsumed auto-projected edges will disappear. It is because Inventor assumes these projected edges are not needed. The exception here is if you manually project the edges or the loop, the projected edges/loop should stay.

Thanks!

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Thank you for your reply and the information therein. Is there a reason that the autoprojected edges should turn off when a feature command is activated? I've created an exmple of what I'm experiencing and attached images.

Notice that the projected edge is visible while editing the sketch but once a feature is called, the edges disappears and the profile is incomplete.

I've worked around this problem several times but I'm just wondering if there's a way to autoprojected edges and avoid this problem.

[johnsonshiue]

Hi! Do the line segments have coincident constraints to the projected edges? If yes, the behavior shown in the second image is wrong. It no, the behavior is consistent with my explanation. Could you attach the part here?

Thanks!

[Anonymous]

The problem with sending you the file associated with those images is that they're simply used to demonstrate my issue but the issue was not actually recreated.

Let me ask you this, should I encounter the problem again, what would you suggest as a solution? In the past, I've sketched lines overlapping the projected edges so that my profile boundary is correct.

And to make sure I understand your explainantion, you're saying that if an autoprojected edge has no new sketch lines constrained or connected to it, it will not appear when a feature is created?

If this thread lasts long enough, I'll post a part file when I encounter the problem. At the moment I do not have one available.

[johnsonshiue]

Hi! Indeed, with "Auto project" off, if the projected edges do not participate in dimension/constraint or they are not consumed by a feature, they will be gone on editing the feature.

Personally I think you might want to turn the option on all the time since you do want to see projected edges consistently. It is possible there could be workflows leading to behaviors other than I described before. Next time when it happens, please let me know asap.

Many thanks!

[Anonymous]

I think I may need to wait until I have a good example to properly convey my point. I do have Auto Project on.

I could keep at this but I feel like between those contributing we're just running in circles. I'll wait until it happens again.

Thank you for your time and consideration.