Boolean difference not working

I’m trying to carve (booleandifference) out a notch using a block I created. Instead of subtracting the block from the rod, it’s welding the two together. The same process worked fine on the other end of the rod. Any advice appreciated. thanks

LeftFender7,9,13,41.3dm (1.3 MB)

Have you tried “boolean two objects”?

You pick the two objects (first, second) then it shows you a preview of the two unioned. If that’s not what you want left click and it will show you the next option (I don’t remember the specific order, but it will do difference, A+B, A-B, etc. it will keep going around the circle of choices with each left click until you decide what you want (if any) then you right click (enter) to accept.

I think I’ve discovered the problem is that I’ve got open edges/open polygons. That keeps it from working.

Of course. That’ll do it every time. Glad you found it.

solved ?

_showEdges to find naked Edges
_properties (should show closed solid Polysurface)
_dir (should show normals, they should point outwards)

avoid surfaces that are (nearly) co-planar / locally the same - see screenshot.

if boolean difference fails and rhino show s text-dots - mark a single text dot and read the info / secondary text in the property-window