If you sat 1000 monkeys down at 1000 3D-printer Makerbots, would you eventually end up with an A-bomb?

No, because they do not have access to weapons grade uranium, nor the eplosives to compress the urianium beyond critical mass.

Well, no. Makerbots only print plastic at this time.
None of the 3-D printing technologies mix materials in the way you’d need for an A-bomb.
And certainly none of them currently print uranium or other fissable material.
...You could print some parts, though, that’s for sure.

Yes, but not before they made the world’s largest 3d printed statue of David Hasselhoff.

No because before that happened they will have typed out a message reading ‘We will make an atom bomb one day that will destroy us all. Please stop us’ together with a stamp and an envelope addressed to the UN.

The chances are about the same as one monkey (or jelly) sitting down and writing a sillier question. ;-)

You most certainly will

Nope. The hottest 3D printer I know can only do Titanium – nowhere near what is needed for an A bomb.

3d printing plastic is old tech that just happens to be geek-chic right now for some reason. An A-bomb shell could be made out of plastic but no uranium = no boom. Monkeys would probably tear apart the makerbot before printing anything.