Rusty extruder filament feeder teeth - NOT gear teeth
Hi,
I am well aware that the teeth on the drive and idler gears can rust as is documented in https://help.prusa3d.com/article/3EMxwPQU0B-bondtech-extruder-gears ? But I have significant rust build up on the part of the gears which grip and feed the filament.
However, the teeth on the filament feeder part of these gears on my Mk3 have gone rusty and I am not sure why. Please refer to the attached images. The questions I have are:
1) Why did it happen? The printer was not used for approx 5 weeks but that should not be enough time for it to rust and what would cause it to rust.
2) Has anyone else experienced this?
3) Do I need to replace the gears?
I first noticed it when I tried to load filament and it wouldn't load so I unloaded the filament and noticed rust in the filament. I've cleaned off the surface rust off the idler gear but not completely off the drive gear, that's not really possible unless I strip the extruder. The printer is working fine now but it squeaks. I know I'll need to realign the extruder gears which - should- get rid of the sound but I thought I'd ask the forum to see if it is common and if I should replace the stock gears with an alternative.
Thanks for any feedback.
Re: Rusty extruder filament feeder teeth - NOT gear teeth
Are you certain this is rust and not degraded filament grindings? Is the metal itself eaten away?
Take some of it and heat with a flame. Rust won't be affect much by the flame, but degraded filament grindings will burn.
If it is filament grindings, then you probably have idler tension a bit too light and it ground some filament some time in the past.
Rust is very unlikely, especially to be at that location and both gears. The only mechanism I that would promote it there is some awfully wet filament over a prolonged period. Your nozzle would be sputtering away were that the case.
Re: Rusty extruder filament feeder teeth - NOT gear teeth
Thanks for your reply, yes - I did think that it was odd that the rusting was only in the filament feed area. I'll test as suggested if the build up occurs again. I've already removed most of it.
Aside from the colour of the deposit, there was the smell, which smelt like rust but then again burnt material can have a pungency to it as well so thanks for the suggestion.