I seem to have been lucky enough to have discovered a market outlet for several items I produce on my FF, to the point where I'm starting to get really nervous about having a sudden equipment failure (and subsequently a bunch of unhappy customers if there is a delay awaiting replacement parts). My FF is almost a year old and over the past month or so has been running 12-15 hours a day. My extrude/travel speeds are always kept at 45/70 and I use PLA exclusively. So I'm hoping to get some advice on what sort of parts I should keep around as they're most likely going to be the ones that break first? I already keep an extra y, x, and z belt around as by appearance I assume they'll be the first to go. Nozzles, thermo couples, and heating cartridges were just replaced one month ago. Any other advice would be appreciated!