in Eurem Browser.
Unless it has a chance to explode every time you use it, i don't think this fits the "engineering" theme very well.
If all you have is ENG, this seems the be, sadly, the 'best' way to 'farm' Expulsom, only thing you can craft that DOSN'T cost Expulsom
As a nice little touch the outer jaws of the weapon (tool?) are animated to open and close.
Just make sure you're careful when you sheathe the thing, don't want to do yourself a mischief.