Replicator 2 making strange grinding noise - extruder gear worn out?

[Zhall]

Hey 3DP Boards,

After realizing that Makerbot shut down it's group support forums to drive everything through their $100 support ticket system literally 3 hours after I posted... (obviously haven't visited them since they were closed)

http://3dprint.com/11478/makerbot-google-group/

Brian Esquivel, yes that's me... (I'm just as weird-ed out by it as you are)...

...I found this forum in hopes of finding help c:

My oldest machine (Primus), who recently got a new friend (Bulbi) (both replicator 2's) is having a grinding issue originating from what I believe is the print head.

https://www.youtube.com/watch?v=tKvQ...ature=youtu.be

I've opened it open and seen major wear on the extruder gear within the print head, and yes, the tension upgrade has been installed on both machines.

A quick stroll through Amazon led me to a listing that is out of stock?

Is this the offending piece of my machine, if so, where can I get another one?

Thanks! c:

[DragonXtreme]

Is this what you are looking for?

http://www.amazon.com/Stainless-Stee...der+drive+gear

Also several listings on Ebay for drive gears for the Rep 2's

[Zhall]

Is that indeed what needs replacing?

[DragonXtreme]

You said that you opened up the print head and saw major wear on it. Was just pointing out a source that had it in stock. It could be that the tension upgrade is not aligned correctly causing the noise. You could swap the gear from the newer machine to see if it makes a difference or at least compare the tooth depth between the two. It could also be the bearing and not the gear that is making the noise or even the drive servo. Unload the filament and run a load cycle without filament and see if the noise is still there. If it is look at the bearing or servo.

[Zhall]

Dragon,

I tried loading with the front fan and heat sync off so I could observe what was going on. There was no grinding during load/unload.

I tried printing without filament and the grinding persists, although it is not very frequent, only showing up on long paths that the extruder makes.

When I hold the side fan (not the main cooling fan) the grinding seems to get a lot quieter, my hypothesis is that that fan is rattling inside of it's case when not in use?

As for the bearing I haven't looked into that yet.

Edit: This only happens on large parts, I just did a whole build without it grinding once.

I noticed that if the filament touches the side of the extruder feed hole then the vibrating starts.

I think it is simply the fact that the guide tube doesn't stay in place during a big build, and the filament is vibrating against the walls of the extruder feed.