I'd been waiting. I'd saved up the necessary materials to make two Clockwork Power Limbs. And then I made them. And then... they ended up in a single stack and when I tried to equip them one just disappeared. Can something be done about this?
Sadly this is an old bug, if you're lucky you can unstack them with alt + click, if not well... :/ the workaround is to equip the first one before making the second. It's on the todo list...