Bug snapped up from people that for some reason never bother filing bug reports themselves..
The assembler recipes for machine casings in experimental are exploitable.
Arc furnaces, fluid extractors, disassemblers and so on always use the crafting recipe when deciding what to give back.
So you can make a max machine hull in the assembler with 8 neutronium, spr. conducting wires and C2F2,
and then get back 9 neutronium by putting it in a fluid extractor.