Stitch gaps from intersects and fillet (plus fillet disaster)

[Anonymous]

Yes, it's the dreaded gaps question again. I haven't used Alias seriously since 2010, and though 2015 has some very nice new tools, I still find it strange to see things like this above.

All surfaces are quite basic, max 5x5, and the trims are overbuilt and the fillet is just G1... yet still this happens. What am I missing? Any tips would be greatly appreciated.

Also, the massive hole at the bottom... I just have no idea where that comes from!

[Anonymous]

Ok, since nobody stepped up, I managed to figure out the first part of the answer to the gaps, at least: Construction options.

I still find it weird that Catia V5 settings, which many recommend, produce gaps with these very simple surfaces, but increasing the "maximum gap distance" fixed it... can't help to think that's cheating, though. 🙂

Still have no clue why the entire surface of that bottom fillet behaves like that, though... but will continue to investigate (but still hoping for some expert level answers and tips here)!

[duaxiong · Accepted solution]

For the Surface Fillet surfaces, Turn OFF Explicit Control.  This may make your data heavier, but it will measure more accurate.

For the other stuff, unless you have CV matched natural boundaries, everything is built to a tolerance...this means gaps of some sort most of the time.  You will need to increase your construction tolerances to overcome your Stitching tolerances, or just relax your Stiching tolerances.

[Anonymous]

I know some tools have explicit control, but I don't see it in Alias Design 2015 SP2:

[duaxiong]

It should be there right under Form Factor, but it's not surprising since you're running Design.

I do find it odd that it would be ON with no way of turning it OFF though.

Use Square instead.

[Anonymous]

It's very weird. The reason might be that the shelves I use are imported from Automotive. I have to reset the tool every time in order to turn explicit off.

I marked the question as answered, but I'd really like to know why the intersected trims get gaps in the shell with Catia V5 settings, but perhaps that discussion should be a proper topic on its own...

[duaxiong]

A fix then might be to create a new Surface Fillet instance in your shelf with your current version.

As for your settings, the Catia preset matches the tolerances for stitching in Catia; it does not set the tolerances for your Alias Stitching tool.

[Anonymous]

I just set the construction options in Alias to Catia V5 again, and I got gaps in my stitch (red arrows in above post). Then I switched to my custom lower tolerance, and they went away.

Can you explain what you mean, because to me, it seems to set the tolerance in Alias as well.

[duaxiong]

I think you are mis-reading what I wrote.  The Catia preset does not change Catia's settings...it simply MATCHES Catia's settings IN ALIAS to help your surfaces solidify IN CATIA.

Alias has it's own Stitching tool and it's tolerances are set independently of the Construction Preset.  This means switching from the Catia preset to your own preset does not change your Stitching tool's tolerance setting.