Lip on curvy lid

[alanambrose]

Hi,

I want to add a simple lip and clearance on a lid. Something like the attached pdf.

Except ... the part is more curvy than an oblong - see jpg. Hmm ipt is too big to post but can be found here:

https://www.dropbox.com/s/u4dapm757c3l5xv/Exported%20lid%201.ipt

When I try to thicken/offset any edge of this part I get a 'did not produce a meaningful result'. This is AI 2013 btw.

Any creative ideas? Fusion? Rhino?

TIA, Alan

[CCarreiras]

Hi!

What's the dimensions you need for that Lip?

[JDMather]

I noticed a lack of symmetry in this area that I would question.

[alanambrose]

Yes, that bit's a bit tricky and is the result of a loft and a couple of extrusions intersecting. Seems to have trouble with even the simplest part of the curve though.

Alan

[alanambrose]

1mm x 1mm and I was planning to make a 0.5mm clearance 'solid' to cut out some clearance - much like the example rectangle.

Regards, Alan

[alanambrose]

It is, of course, actually symmetrical but it is more complex than would be optimal.

Alan

[JDMather]

---

@alanambrose wrote:

Yes, that bit's a bit tricky and is the result of a loft and a couple of extrusions intersecting. Seems to have trouble with even the simplest part of the curve though.

Alan

---

When I see something like this - I question all of the geometry construction techniques.
Can you attach the original file (from your picture it looked to me like you are doing too much work).

Find the red End of Part marker in the browser.
(End of Folded on sheet metal parts EOF)
Drag the red EOP to the top of the browser hiding all features.

Save the file with the EOP in a rolled up state.

Right click on the file name and select Send to Compressed (zipped) Folder.

Attach the resulting *.zip file here.

[alanambrose]

Hi JD,

>>> I question all of the geometry construction techniques.

I know it's a tradition to tell nearly everybody with a question - "you're an idiot, don't do it like this". But it doesn't actually help the questioner get any closer to an answer.

Fact is, with AI (and SW etc is the same) - at some points they just give up with 'ahhhhh, eeeeee, I can't do that, I can't figure it out'. Sometimes because there's a problem with the geometry but oftentimes the algorithms just can't deal with anything remotely complex. (The lack of error reporting is inexcusable - and I have also written software algorithms for many decades. It is perfectly possible to report good errors - but it does take more work.) That's not the point I'm trying to make here though.

I bet Rhino will make short work of this task - and I have a Rhino guy looking at it. I appreciate AI isn't Rhino and shouldn't be.

The question is - "given AI isn't reporting back what is going wrong, what's the best guess at what the problem is, and how do I get relatively quickly to an acceptable solution"?

If you know the answer or have some guesses, great. If not, "I question all of the geometry construction techniques", isn't helpful to me. I appreciate it may may you feel good for a bit though.

Regards, Alan

[JDMather]

Of couse if you hang around here a bit you would find out that I would spend hours on your part finding a solution.

Without the file - it would all be a guess.

[alanambrose]

Hi JD,

That's a kind offer, but I can't release the whole part out publically unfortunately. I did do some experiments with a lip on a test part made from 3D splines and it did give up in the same way at some point. My theory is simply that it's the sharp convex corners that cause the algorithms to give up.

Rather than take up lots of your time, let me see whether the Rhino solution works. I'm interested if anyone goes (and at what point they go to) fusion, alias, rhino etc when the work gets too curvy. If you have not guessed already this is a human body related part and so pretty much all the curves are necessary.

Kind Regards,

Alan

[wilkhui]

Hi Alan,

Would you be able to send me the parts to avoid making your files public? My address is inderjeet [dot] wilkhu [at] autodesk [dot] com

Thanks,

Indy

[alanambrose]

Hi Indy,

Yes I'm happy to if you can confirm that the part won't be used for anything other that internal Autodesk purposes.

Regards, Alan

[wilkhui]

Hi Alan,

Thanks, yes, I'll treat the parts in confidence and won't share them outside of Autodesk.

Looking forward to your email,

Indy