I searched the forum for a thread like this but did not find it. Please point me to it if I missed it.
I’m coming up on about 950 print hours on my H2S/AMS 2 pro since getting it in September. Knock on wood, I have fewer failed prints than I can count on one hand, and two of those were my fault. I keep it well maintained and print 95% of the time with PLA, 5% PETG. I did a thorough cleaning and lubrication around the 500-hour mark, and now I’m getting ready for a bigger 1000-hour maintenance check, and am thinking of proactively stocking any parts and consumables that I might need, since I want to avoid downtime.
For those of you with 1000+ hours (or well beyond) on your H2 series machines:
What parts actually wore out or failed for you?
Were there any components you wish you had replaced proactively?
Did you run into issues with things like fans, extruder parts, sensors, belts, or electronics?
Any motion system components (rods, bearings, lead screws, etc.) that needed more than just cleaning and lube?
Appreciate any experience you can share, I am hoping to stock smart and avoid future downtime on this so-far very reliable workhorse.
I have an H2 and only purchased the obvious, the cleaning pads and the nozzle blocker and may be some other cheap stuff but I’m sure I will never use them…
I purchased a tons of parts for my P1S that has a couple of thousand hours and never used any…
I looked at the parts I’ve been through in 3 years with the P1S.
When I ordered the H2S I also ordered most of the hot end parts. TH board, filament sensors. These are parts that get mucked up when there’s a build up, or I screw the pooch.
Really haven’t worried too much about other things, other than nozzles.
From my experience with an H2D (dual‑nozzle, but still very close to the H2S in overall architecture), there are a few parts I would definitely want to have on hand to avoid downtime once things start to wear out or run hot on a regular basis:
Hotend cooling fan
Part cooling fan
Toolhead enhanced cooling fan (upgraded version, good backup)
MC board fan (if this fails, the entire machine stops)
Eddy sensors
Hotend heating assembly
TH board
Silicone sock for hotend (protects the heating block, easy to burn or contaminate)
Nozzle wiping pad (wears out, especially with frequent material changes or abrasives)
Purge wiper (same reason)
Cable chain (can break under mechanical stress over time)
PTFE tubes (can wear out more or less quickly depending on use, essential to have spares)
On my H2D, I have had the hotend cooling fan, part cooling fan, Eddy sensors, heating assembly, and TH board all fail at some point, and each one can stop you dead in your tracks when it goes. In particular, the fans feel somewhat undersized for sustained higher‑temperature printing and more demanding materials (ASA, ABS, PA, and especially reinforced or engineering‑grade filaments). As the overall thermal load around the toolhead increases, both the fans and the heating assembly seem more likely to fail or degrade over time.
The reason I specifically mention the TH board is that when I had to replace the hotend cooling fan (the one deepest inside the toolhead), I discovered that during factory assembly someone had effectively glued my Eddy sensor connectors in place. As a result, it was impossible to unplug them without destroying both the TH board and the Eddy sensors at the same time. Having spares for those parts turned out to be the difference between a quick repair and a completely dead machine.
Even though the H2S is a single‑nozzle system (unlike my dual‑nozzle H2D), I would still consider keeping at least one spare of each of those parts on the shelf. That way, when something eventually gives up, you can swap it immediately instead of waiting on shipping or support and having the printer sit idle.
My H2S has 1150 hours, the only things i did was cleaning, lubrication every 500 hours, a new ptfe from buffer to print head. In spare i have a belt for xy and tensioner, because i had a sound from the belt but solved it with a alignment of the tensioner.
Well… I’d like to thank everyone for the thoughtful advice.
Apparently my H2S was also following this thread, because the PSU started screaming the very next day. Perfect timing, like the printer said, “Oh, you’re talking about preventative maintenance? Hold my beer.”
Bambu support has already been awesome and a replacement PSU is on the way, so no complaints there.
So I guess we can add “power supply fan” to the unofficial long-hour watch list of:
small fans in hot places
parts you don’t think about
components that wait until you start a long print to fail
After some internet research, the MOSO 24V power supplies have a history of bad fans compared to the Mean Well power supplies that they apparently used to ship with. Still very impressed overall with ~1000 hours before the first real hardware issue isn’t bad at all. Just figured I’d share in case anyone else is building their “what could possibly go wrong” bingo card.