Boolean union running on and on and on - on simple box

Unable to Boolean Union this structure which surrounds objects for 3D printing, its doing it, so it seems, but the timer remains showing after 4 or more minutes.

why ?

as such unable to send to print.

foiled at the last hurdle.

attaching it, had to zip it as this simple structure is massive. 34Mb.

I created a load of instance cutters to knock out the square holes, they wouldn’t, had to explode them, then Boolean difference, then made this cage up that is compulsory for this company, and dolled up a few edges to get it neat. squares had to be a certain size and box also so a few extra bits added to finish it. It surrounds with 1.5mm clearance the 3D items inside that mustn’t fall through the holes.
Sinterbox boolean timer (2.9 MB)


Simple answer: Do not try to boolean adjacent coplanar or overlapping surfaces, polysurfaces or extrusions. Booleans are not the right command to build this kind of geometry. Use rectangle curves for the rectangle cutouts and extrude them, then use rectangle curves and _PlanarSrf to create the larger faces. Do the same for the inner wall and just _Join to create a closed object.