"Combine" solids fails, "interference" fails, can't complete my piece!

[dunderhead]

I have four really complex solids and I'm struggling putting them together. I tend to get a "problem combining geometry" error message (below), where I'm guessing that by the "validate" tool is meant the "interference" tool.

I found out that when I want to join A and B together and I land in such trouble, there's a useful new math identity:

   A U B = A U (B \ A)

that is, I modify B by cutting with A before joining with A. But this time around, I completely stumped: the two bodies shown in excerpt below (one selected, the other not) do intersect, I'm sure, but I can't join them!  Worryingly (?), "Interference" reports no interference.

This is a real puzzler, how do I debug this? Almost reached the summit!!

-dh

COMBINE

---------------

Error: Combine9:
Error: There was a problem combining geometry together.
Check the inputs with the Validate tool, and avoid having faces and edges that are nearly coincident. If attempting a Join/Cut/Intersect, try to ensure that the bodies have an overlap.

[dunderhead · Accepted solution]

I think I diagnosed the problem: a case of numerical instability in the core CAD engine. (I've been driving it hard!) By nudging one part around by microns, I received (a) the same, (b) new (attached) or (c) lucky case, no error messages. In case (c) I was able to visualize the intersection using the "interference" tool. So solution to combining A and B: insert a move command for say A in the timeline before the combine command. Then put tiny offsets into the move command until the combine command computes. The lucky number was 50 microns in my case.

-dh

Error: Combine10:
Error: edge split at one end: maybe coincident geometries in input body

[wilkhui]

Hi dh, would you be able to share your model with me? My address is inderjeet [dot] wilkhu [at] autodesk [dot] com.

Cheers,

Indy