Multibody- Combine order operation

[admaiora]

Hi,

I have this issue, quite often.

Imagine huge multibody (300/400 bodies).

Teorically you could join every body with every body, even the bodies not touching, (the only limits should be tolerances issues).

Let exclude the tolerance issue, normal  bodies.

If you want to combine all in one body you can struggle with errores, but if you try to combine them in another order you can success.

I can success (struggling) manually, but what about a simplify in the upper aassembly? The app will combine in cronological order and will fail very probably.

Can you me clarify how think Inventor in these cases? Thanks!

[Gabriel_Watson]

Do you have more info on what works? For example, I would try combining elements in an order that slowly increases the overall bounding box, so that new additions don't get "injected" into an area that has already been populated.

[admaiora]

Hi Gabriel.

I use that approache,

"try to join this grup of solids, with that" > nope

"Try with that so"  >>ok

And so on the interpolation.

Finally i get ussually 1 solid >> supersuccess

or 2 or 3 bodies.

I would like to understand how to improve this flow that is quite random to me, there is no reason to fail, but fail, then not fail

[Gabriel_Watson]

Do you repair all bodies prior to combining? I find that can usually help. Also, use the recommended CTRL+F7 and Rebuild All to ensure no corruption or rendering glitch.

[admaiora]

I don't have available repair bodies/find errors.

[admaiora]

I think the instability may be that the bodies are from a derived assy/parts.

[admaiora]

Nope, it's geometric. The same result with a clean step.

So the questions are 2:

- if there are geometric issues, why is it possibile to join them to some body and not join to others?

-Is there a way to find the specific geometricl issue?

[johnsonshiue]

Hi Matteo,

I could be wrong but if I understand how it works correctly, when multiple solid bodies are Boolean together, the modeler dictates the order (I don't think Inventor can dictate that). It sounds like a geometry specific Boolean issue. Likely there are tolerant edges on the model. I suggest you unstitch the imported solid bodies and restitch them in very tight tolerance (0.00001mm).

Many thanks!

[admaiora]

Omg.

No sure, how to unstich e restich the bodies?

[johnsonshiue]

Hi Matteo,

I would select the base features in the browser -> right-click -> Repair Bodies. Then unstitch one solid body at a time and stitch the surfaces back to a solid at 0.00001mm gap tolerance.

Many thanks!