Extruder gears - terrible lifespan?

Hello, for the last 14 days, I’ve been experiencing slight underextrusion on all of my prints, which were completely fine before. Today, I found the cause - the extruder gears have worn out completely. They are completely ground down. How long are they supposed to last? My X1C has only about 1200 print hours, and this happened. That doesn’t seem like a lot to me.

Is 1200 print hours enough to consider it as wear from use or a reason for replacement under warranty?




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It really depends on the filament you are printing. Personally I consider this a wear item but you can see if they will replace it. Luckily replacements are not expensive.

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I’ve been exclusively using PETG and PLA for printing, yet I’ve noticed wear only on gears that aren’t in direct contact with the filament. If the wear were in the ‘filament grip’ area, I wouldn’t have brought up this issue.
I have already placed an order for spares but I don’t like the idea replacing it every 1200 hours.

Also I have uploaded few photos of the problem in the first post.

The pictures give good insight into the issue. Thanks for uploading them. If the filament grip area isn’t worn I’m curious as to how the the filament is under extruding? A don’t feel that a little bit of slop in the drive gears will cause that. It is concerning how many metal slivers are visible from the wear. That’s just begging to clog a nozzle. Is this the first time you have inspected/cleaned the gears in the 1200 hour span? I think I will start checking/cleaning the extruder ever couple hundred of hours of use on my machines.

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been wanting to try

I’ve replaced several set of these gears since I’ve had my 6 Bambu machines. They’ve each got ~4000 hours on them now, so I definitely keep various replacement parts on hand. The dust in there is troubling (I might try some lube), but the yellow gears have mostly been the issue for me where the teeth get worn and start skipping (see the flat spots in the images).



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Question: Is the Black Dust magnetic? Or can you pat parts of it off over a white cloth? Carbon dust from the carbon guides that found its way onto the tooth flakes? It will have magnetizable durst from the gears, the question is whether it still has carbon dirt from the carbon guides too…

Gear damage always happens - even with the most experienced companies. Since Gears are always a matter in themselves - usually always an even and an odd number of teeth to the next gear. The consequence: That smalles manufacturer scratch on one tooth quickly leads to all teeth by a total damage to all teeth. But seens the number is even and odd, the wear is afoidet to the max time window…

Well for sure it will have iron and rust in, the question was how much of the dirt holds on a magnet and how much of the dirt is folling of to a white cloth :wink:

Another very common problem is salt water during shipping across oceans and a shipping package that is not properly sealed… and rust surfaces then very quickly settle on tooth flakes, which then completely destroys gears very quickly in sea air. In fact, every steel part breaks down very quickly (Sometimes it doesn’t even take 24 hours in sea air) and if this was happen, 1200 hours were already a lot.

However: Gear damage always happens - even with the most experienced companies.

What error, if any, does the printer throw when it gets bad? Or it’s just a failed print on appearance.

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No errors, just underextrusion problems. Small at first, then increasing as the gear continues to wear. I could never hear anything (too noisy in my printer room), but could eventually feel it happening with my fingers on the toolhead.

So for unexplained underextrusion.

Take a peek at the extruder gears would be wise.

Thanks!

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After seeing those pictures above I had to check. My machine has 1100 hours, the extruder assy looks like its brand new on the inside. I mainly print ABS.

I agree; wearing out extruder gears has never been a problem on my other printers running Bondtech extruders.

Ive had no issues with wear on my gears after 6 month non stop printing, some with abrasive Nylon CF, PLA CF, PETG CF and glow in the dark filaments. There is a new aftermarket gear set that just came out on Ali and I ordered. They have angled helical gears for smoother meshing (might improve extrusion consistency) and nano coating to prevent wear. Have not tried it yet as its still on the way. Just wanted to show you guys in case anyone is interested.

Ive had both hits and misses with aftermarket Ali parts… Love the CHT quick change screw in hot ends, print on ludicrouse 100% of the time. Also tried aftermarket part cooling duct with 3 cooling nozzle, and after a lot of testing the cooling was worse then stock. Will do some calibration cubes with these when they arrive and report if it makes extrusion more consistent and walls more smooth or not.


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To me, dust like that is fretting corrosion. From ScienceDirect.com: " Fretting corrosion is defined as metal deterioration caused by repetitive slop at the interface between two surfaces in contact that were not intended to move in that fashion. Fretting corrosion is usually a combination of corrosion and abrasive wear."

It typically shows up in the interface between a shaft and bearing or bearing and housing. There is movement where there shouldn’t be. It’s one of the first things I look for when doing a PM on or repairing one of our packaging machines at work. That begs the question why in some and not in others. Things that come to mind are running in ludicrous mode which will put greater stress on things as the hot end is just barely able to put enough heat into the filament. Another is filament that has additives that require more force than plainer filaments. Again, this could more stress into the system. It’s also possible that some extruders are out of tolerance as far as alignment and fit of bearings in housings. And lastly, some filaments may release particulates that cause issues, maybe by messing with tolerances due to build up or chemically in some way that I don’t know.

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I recently spoke to Bambu about 2 of my p1p’s where I was suffering from extrusion problems. It was the gears and Bambu blamed me for it. They informed me I was not servicing my machines (enough). They refused to replace the gears on the 2 printers and I had no other option but to purchase new ones.

As soon as you see black dust forming on the teeth of the yellow gear you are meant to clean the gear assembly according to support.

@maximit which quick change Nozzle are you talking about ? The standard CHT from 02.-1.0 ? i have ordered the steel extruder gears too and the Nano coating one the older steel gears looks much better then the original one. @LUL3D your extruder looks terrible i print a lot too but never seen such an extruder. do you never clean the mainparts ? the worn is terrible for 4000h. do you have also noticed extruder cloging or just underextrision ?`!

I had under extrusion issues too after about 1600 hours of printing. There was quite a bit of filament dust in there and the gears themselves had a fair bit of white PLA stuck in the grippers.

On an old Bowden extruder I had unexpected and premature wear issues. Turns out that they use titanium dioxide to provide the colour and its particularly abrasive. So, I’d check a bit more often than usual if running through a lot of white rolls.

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Prusa solved it with their newest extruder gear setup. Give bambu a few generations and theyll have something similar.

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Hi StreetSport,

Well, I also noticed that they made changing the direct extruder easier on the MK4, but somehow Prusa was never really anything for me. Maybe because of my professional background - Develop it. If it works, move it to e.g. Poland to get the prices down. When it is so established, it will be adopted copied by Asia, so have the next technology step ready before it is copied… (except Japan - they are developing themselves and are at an extremely high level). So there’s constant wandering, when you oversleep you’re just gone. And may but just may Thaiwan will now ching this a litel by there next 3D printer due to expiriance since decades in adapting processes in Thaiwan, have achieved seriousness…

I have two requirements – one as a professional and one as a privat homeowner.

Professionally it will be T1 once they have spaghetti detection installed. Quick replacement of the entire direct extruder. Since it’s not a question of when things like the extruder gears break, it’s more a question of when they break… So a T1 for expensive filaments but small parts and more round than square. By a quick all over Direct extruder exchange.

Privately the requirements are massively diverent. Direct extruder change in not more than 4 minutes since not only extruder gears are breaking. Minimum spool size at least 2 kg, spaghetti monitoring and min. partsize of 300 x 300 mm. Full own monitoring: spaghetti, first layer, and so on. I’m working and don’t have time for the printer. Before I used the printer for small projects that printed in 24 hours and by a max. weighed of 250 g… Today I wait 1.5 weeks and it weighs goes up to 10 kg (in several screw-on parts) and will be mounted within in 1-2 hours. I rarely go to my private workshop anymore - I have to clear out the workshop machines :wink: So 1 kg goes quickly through this small exdruder gears. That day, after day, after day, after day…Filament prices are becoming more important than printer prices - so the spools are also becoming correspondingly larger.