Boolean Diff fail and MergeAllfaces deletes some surfaces

why wont Boolean Difference work on the RHS red bar, was ok on the left.

Then I try for a tidy up, run MergeAllFaces and end up with surfaces vanishing inside middle area.

why ?

how do I merge co planar faces in this ?

It must be good to go for 3D printing.

Boolean Difference fails and MergeAlFaces nukes faces.3dm (4.2 MB)


on V7 i get this:
(saved as V5)
both polysurfaces stay / become a solid polysurfaces with 572 edges, no naked edges.

in v7 its

Boolean Difference_02_rh5.3dm (4.1 MB)

you have an internal non manifold surface here-

extract it, run cap, run showedges to check for naked edges and then do your boolean again… works fine here.

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exploded it, I see I have two faces abutting when I should have trimmed out of one or both what was not needed , thanks for that.
Q1. What is the command to run to find such co planar faces as such had happened ?

With Jims fillets taking me through more than one layer, my original plan of fillet between layers and boolean union the layers together would have fused together such co planar faces.

Q2.What then is sufficient to remove such leaving only faces that form the solid ?

I decided to trim my way through this item, joining surfaces as I went, to accomodate Jims fillets, but somehow didnt trim those two.

It has been very mentally taxing as you can see. a definite candidate for 3D printing and not metal milling , being ‘for show’ and not function.

here is what that face should have been
Boolean failure co planar faces fixed.3dm (2.1 MB)


the commands I always use as I’m prepping for 3d printing or cnc are:
selopenpolysrf this will highlight any polysurfaces that are not closed.
Selbad this will highlight any issues with parts of a model that cause them to be “bad” which could mean a lot of things but it a 100% trigger to go looking closer at the part.
Showedges (naked) this will show any edges that are naked (unjoined) or non manifold (sticking up like a fin)
check which will bring up a dialog with lots of info about the part any any potential issues

generally speaking, if you use showedges and see any pink, you have to go digging into why.

that’s how I found your problem when I looked at it, and it only took about 5 seconds to find the issue.

Thanks, now copied to my list of useful commands.


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