Combine Error - Why!?

[Beyondforce]

Hey Guys,

I hope you could help me to crack this one:

Cheers / Ben
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[michallach81 · Accepted solution]

Try to offset narrow edge of canopy so it don't match outer surface of bigger part, it should help.

[Beyondforce]

Thanks Michal, it worked. I wonder if there is a logical explanation to why I couldn't just combined them.
Anyway, now I know for next time 😉

Ben.

[michallach81]

Most likely is caused by inaccuracy. When some entities are not specified by the user but are a result of some computation, they are approximated. Take a look at this example:

As you can see I've built two different surfaces with use of the same trimmed edge. They don't match. On the other hand, two different surfaces but build on the edge (spline in this case) but specified by the user, match perfectly.

Your case is similar. Best idea is to avoid coincident faces when combine.

[Beyondforce]

Personally it doesn't make sense. If you combine 2 bodies, why does it matter how they are touching each other!?
But in the future, I will stay away from coincident faces.

[wilkhui]

Hi Ben - looks like you hit what's known in the geometry office as Deadly Sin 3: Near-coincidence (take a look at page 23 of this document which was written for Inventor but is mostly applicable to Fusion).

Of course, it's always possible that you've just hit a bug.

Can you share your design so that we can investigate?

[michallach81]

Hi @wilkhui, do you have more "white papers" to share? When I try to help others, some of my explanations are just speculations based on common knowledge, it would be nice to have some insight in how modeling is build in Fusion.

[wilkhui]

Hey Michal - here's @jakefowler's AU class that went with that pdf: MA2843: Get Smart with Autodesk® Inventor® Modeling

There is tonnes of information on the internet, normally I turn to AU classes or YouTube videos myself (yes, I still watch these things, you almost certainly know the software much better than I do).

Have a look through the list of Fusion 360 AU Classes, pick the ones you're interested in and grab a beer . Then, if you have time, do the same with the Inventor AU Classes. If somehow you still have time then go for a walk, play some sports, etc. You won't have time left after that, but if you do, search around for the AU presenters who you liked the most, they've probably uploaded more stuff or have blogs that you can follow etc.

[Beyondforce]

I followed @michallach81 idea and the problem is gone now. I have made a lot of changes since then, so the file won't help you anymore. But if it will happen again, I'll contact you.

Thanks.

[wilkhui]

Good news - hope it continues to go well!