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Toroidal Bend Issue

Re: Toroidal Bend Issue

5.0.0.0

Re: Toroidal Bend Issue

Definitely worth having PTC look at it 🙂

 

I'm still running C2 and C3 so I couldn't see it if I wanted.

 

And yes, I am running these by choice.

Not sure C5 would work in an environment where C2 and C3 need to continue to work properly.

Re: Toroidal Bend Issue

Just to be sure, you also altered the accuracy_lower_bound setting?

About part accuracy settings in Creo

Re: Toroidal Bend Issue

Thanks for the reply pausob.

Yes, that is at the max allowed of 0.0001.

Re: Toroidal Bend Issue

I go here when I have to:

default_abs_accuracy .00005
enable_absolute_accuracy yes

 

ac.PNG

 

 

 

 

Re: Toroidal Bend Issue

I think I have done one toroidal bend in my career and it happen to be for a tire tread also...more than 20 years ago...so I am of no help there.

But on occasion, accuracy will throw you a curve ball and something will not regenerate with a superfine accuracy and will regenerate with a much coarser accuracy. It only takes a minute or 2 to try a few values and may help.


Steve Williams
Pro/E Version 15/16 (Circa 1995/1996)

Re: Toroidal Bend Issue

Thanks, I have tried about 30 accuracy settings, and switched between Relative and Absolute, even though there is no import geometry.

 

Re: Toroidal Bend Issue

What am I missing about import geometry?

 

I am assuming that you have tried this with simpler geometry and it works just fine, right?

Re: Toroidal Bend Issue

Relative accuracy should be adequate for any developed part.

Absolute is best suited for when geometry/objects are being imported.

 

At this point, I am trying everything.

 

I also verified all intersections would not overlap as a result of the bend by making all surfaces normal to each other on the tread.  I have not yet received a response from Support, so I have engaged a resource partner to swat the hive as it were.

 

I am really starting to believe this is a complexity limitation on the surfaces for CREO.  There is a threshold I have to have surpassed that the feature stops working.  I have developed dozens of tires with toroidal bends.  This is the most complex tread so far with many small elements, relatively.  Passenger car tires are far more complex, therefore PTC should be able to address this either from a license level or configuration change.

 

If the features work up to a point, then license should not be a factor, imo.

Re: Toroidal Bend Issue

Funny, that's the first time in 30 years I've heard that 🙂

 

You do know what default Creo sheet metal (even empty!) also open with absolute accuracy enabled and set, right?

 

I just had to ask so I didn't have to go and try it.

I do this with physical threads (not treads, threads) and helical sweeps.

They are the most stubborn thing you can do in Creo.  There is very little you can make infinitely parametric When it comes to developing these types of threads that require a lot of rounds.

When I need to tweak it, something fails 90% of the time.

However, there are even more occasions when it will not generate the helical sweet at all.

I find myself reordering the entire design just to get the helix to work.

 

That is definitely not your issue as the process for Toroidal Bend is fairly well defined and straight forward.

 

So let me give you one other option with your last reply...

What if you reduced the height of your tread (assuming this made it work)... and using "offset" to get the final height?  The Offset feature may just help point you to the piece of geometry that is actually failing the full gambit.

 

I wonder if Toroidal Bend is ever really used for tire tread definition by tire developers.

I could see a massive patterning effort to get there, however.

 

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