Join 18 polysurfaces (planks on an ancient ship)

I am looking for a good way to join/merge 18 poly-surfaces (representing planks on an ancient ship). I have tried the different options presented on the forum/internet, but I still have problems join all the poly-surfaces. The boolean union option for example fails with most poly-surfaces and I am not sure why.

Cogship_question.3dm (2.9 MB)

Kind regards,


Hi Sander - there the BU works (V6) if the tolerance is set to .001 on all but the top two planks - (your file tolerance of .01 meters is pretty large for this scale, I’d go to .001 at most). At that point it will be a matter of hand surgery - Intersect the individual surfaces and using the resulting curves to trim surfaces, then rejoin. (1.9 MB)

@Sander_Vos - see if the attached is what you need - getting the top three planks sorted is a pit of a pain as the edges and surfaces are nearly coincident in places.


Sander, I’m curious why you need to combine the planks into one object rather than leave them as distinct objects. If you will be doing stability or other analysis you could create an analysis surface by joining together just the outer surface of each plank.

How about just ‘group’ them?:panda_face:

My guess is he’s headed towards a 3d print…


That would make sense.

Maybe the model will be printed in 3d some day, but that is not certain yet.
The reason for joining all the planking is that I need the inside of the planking as a cutting surface for further reconstructions. Otherwise I would have to cut objects 36 times (2*18 planks).