Inventor 2017 Frame Generator Issues with two x trim

[YannickEnrico]

Hi guys

Yet another problem, and one I've been having for some years (read, earlier releases as well). I finally got around to test the behaviour of the problem and came to a conclusion.

After using trim twice in the same end of a Frame Generator part, G_L stops updating.

Is there any known workaround?

https://knowledge.autodesk.com/support/inventor-products/troubleshooting/caas/sfdcarticles/sfdcartic...

This was the only thing I found from Autodesk in regards to the problem.

Also, 2017.3 doesn't fix it. I found a topic stating that it should fix some problems in regards to the Frame Generator. 

I found some workarounds back from 2011 and 2012, but they don't seem to work anymore. 

Best regards

Yannick

[YannickEnrico]

Is there anything official stated about this?

[cbenner]

Verified in Inventor 2017.3

After the first trim operation, G_L shows the shortened length of the frame member.  After applying a second trim operation, G_L reverts to the original value of the un-trimmed member.

@YannickEnrico  I was able to make this work, however, by applying one trim, and then a notch for the second cut.  My geometry is slightly different from yours, but maybe try this and see if it works on yours?

[YannickEnrico]

Thanks for the suggestion.

I have never gotten Notch to update G_L.. Not in this version, nor through versions through 2012-2016.

I just attempted again in 2017.3, and the issue is the same. Notch doesn't update it - Doesn't matter whether I used a trim or not.

And two x trim still only updates on the first one, not the second one. 

[cbenner]

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@Anonymous wrote:

Thanks for the suggestion.

I have never gotten Notch to update G_L.. Not in this version, nor through versions through 2012-2016.

I just attempted again in 2017.3, and the issue is the same. Notch doesn't update it - Doesn't matter whether I used a trim or not.

And two x trim still only updates on the first one, not the second one. 

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Did you do the notch AFTER a trim, before, or by itself?

My experience has always been that a notch works best when used AFTER a trim... otherwise I see what you are seeing, G_L doesn't work.

[YannickEnrico]

For testing purposes, I tried the following work flows:

Trim -> Notch

Notch

Notch -> Notch

Notch -> Trim

Only the ones including a trim changed G_L, because Notch didn't in any workflow change G_L. 

However, both the first and last still output the wrong length

[Mark.Lancaster]

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@Anonymous wrote:

Thanks for the suggestion.

I have never gotten Notch to update G_L.. Not in this version, nor through versions through 2012-2016.

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Just wanted to comment on your statement..  Notch is considered a fit to the job. It will never update the G_L value.  Meaning in the manufacturing process, the member would be cut to a desired length (so you would trim your member to a certain point pass the notch) and then the person or persons performing the construction would grind the structure to the desired shape profile..

[YannickEnrico]

@Mark.Lancaster I think I've been told that before, but somehow forgotten. 

That explains why I can't get it to work. Doesn't explain how @cbenner seems to get it to work, though 😄

[cbenner]

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@Anonymous wrote:

@Mark.Lancaster I think I've been told that before, but somehow forgotten. 

That explains why I can't get it to work. Doesn't explain how @cbenner seems to get it to work, though 😄

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I should clarify that what I end up with doing: Trim > Notch, is the cut length of the trim.  The notch does not modify G_L, just like @Mark.Lancaster said.  I wasn't clear on this, sorry.  The cut length comes form the trim, and our steel guy knows to grind the notch FROM the cut length.

[YannickEnrico]

@cbenner - Ah, that does indeed make sense. 

Thinking about it, I suppose it makes sense to some degree that it only creates cut length for one trim, because usually you would cut it at an angle. 

Outputting the dimension I want, means you'll lack profiles unless you make three cuts rather than two....