I fabricobbled a liquid nitrogen generator using a cryocooler at home using the same design as Ben at Applied Science [0]. It works very well, I've used it to make liquid nitrogen ice cream many times. It's just slow so I run it overnight.
Applied Science is fantastic channel if you haven't seen it. He's also on HN.
OP's design is much more impressive and hard to build than using a Stirling cryocooler like I did.