Metal Shavings and Clogged Extruder

Hi all.

Love my Taz 4. I have the standard 0.35mm extruder head that came with my Taz 4. Recently the extruder has been getting clogged every two hours or so. I take off the nozzle and soak it overnight, make it super nice and clean, clean out the hobbed bolt, and then put it back on and it prints fine for a couple of hours but then I have to repeat the process.

In addition I’ve noticed that there are tiny, tiny metal shavings in the middle of the extruder assembly. Supplying a picture here. There are lots of shavings and they fall onto the bed. I’ve looked all around trying to figure out what is producing it but I can’t figure it out.

I’m printing with ABS and have replicated the clogged extruder head with the standard octopus print (It has consistently failed on the 2nd octopus that I print - the first one turns out super awesome).

Any suggestions?

In addition can someone suggest the best video for complete extruder head disassembly? There are lots of videos out there - I’m looking for the best one for the Budaschnozzle 2.0.



Hard to tell but they look more flake like. Perhaps they are plating flying off of something. Is the hobbled bolt plated?

If this has been happening and gets in the filament path, those could easily be the culprit with your clogging problem. I’d use a magnifying glass and scrutinize every piece of metal on the extruder and look for plating flaking or other wear.

I took apart the budaschnozzle tonight to try to discover the source of the metal flakes and shavings. I found it here:

This was above the budaschnozzle and part of the feeding mechanism. It is the end point of the hobbed bolt.

The picture is pretty clear. About half of the ball bears have disintegrated. Does anyone know how this could have happened? I’m thinking it was always in bad shape and has been steadily degrading. I’ve had the printer for less than a year and it sees fairly active use.

Also does anyone know if this part: is a replacement for this? If not is there another somewhere? I looked at the packing list of the budaschnozzle here and didn’t see this part. But I also didn’t see anything else that I thought would actually be the thing that I’m looking for.


We had that exact same bearing self-destruct as well. Metal shavings were the tell-tale sign something wasn’t right.

We have a local Lulzbot dealer who replaced them with a different bearing that appears to be far more robust.

Wow, those bearings shouldn’t do that under the relatively light loads they are under. I have bearings on extruders that see 6+ hrs/day for several years and they are going strong. Could have been a bad batch or perhaps the bearing was damaged.

I wonder how many other folks have had this problem.

Do you know what bearing your local lulzbot dealer replaced it with? I’d like to try this part.

This is a standard 608 bearing and you can get them almost everywhere. My local hardware store even carries them.

They are 8x22x7 mm

This is a nice one with a grease shield. I use these on my CNC router:

You can also get some from your local skateboard shop in a pinch

The bearings should not be doing that. Send in an email to with:

  • Order number

  • 3D printer serial number

  • Contact information

  • Shipping information

We’ll let you know whether we recommend just replacing the bearing or whether we’d recommend replacing the extruder/toolhead once we know more.

Sorry you are experiencing some down time.