Filament idler grinding into the filament after a while

Hey guys.

Newbie here with a Taz Workhorse, PLA @ 200 extruder temperature.

So whats happening is after testing extrusion when changing the filament, the extruder grinds into the filament after a while (15-20minutes). Tried keeping the tension at a minimum, problem persists.

This obviously leads to a failed print. Tried two PLA filaments bought from Amazon ( Tesseract).

PS: I had to dismantle and put the tool head back together to clear a stuck filament - dont know if the problem is related.

Images below:

Hi Prabhu,

200°C is too cool for PLA on a TAZ Workhorse. The Workhorse comes with a “hardened steel” nozzle (vs. the more common brass nozzles on most 3D printers). The advantage of hardened steel is that the nozzles do not easily wear … this means you can print using filaments that have abrasive properties such as filaments with fillers or glow-in-the-dark filaments, etc. You would normally avoid using these on a printer that uses brass (or just be prepared to swap to a new nozzle more often.)

But the downside of hardened steel is that it does not transfer heat as efficiently as brass. Also, this printer uses 3mm filaments (vs. 1.75mm). This means that if you use the same temps that could be used on a 1.75mm filament printer using a brass nozzle… you wont heat the filament enough and the printer is fighting to force filament through that hasn’t melted to a soft enough state.

If you select one of the included PLA profiles in Cura LulzBot Edition (I think PolyMaker PolyLite PLA, Verbatim PLA, and IC3D PLA are all on the list). The Verbatim profile (in my version of Cura) is showing 205 … not warm enough. But IC3D and PolyLite PLA should both be using 230°C as the recommended temps and those should be good starting points.

I use a “Temperature Tower” to find the optimal temperature for a filament, but a good starting point for PLA … is 230°C.

A “Temperature Tower” is a part that has several sections … think of it like “floors” in a high-rise building. Each section is printed at a different temperature. There are loads of temperature towers are available for download. See

Download a temperature tower and follow the steps in Cura (outlined in that post) to tell Cura that you want to change temperatures at certain layer heights. Typically each level of the tower is printed about 5°C cooler than the layer below.

Inspect the finished part to determine which layer looks best. You can try to break it to see which layers have the best layer adhesion, etc.

You will likely find your best quality is at a temperature close to 230°C (when I do a temp tower, my 225 is nearly as good as 230… but 230 is just a little better).

It is a good idea to run a temperature tower each time you switch filament types or brands … sometimes filament behavior changes based on filament colors (based on additives the manufacturer used).

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BTW, once your hobb gear chews up the filament, you’ve probably got a lot of filament stuck in the teeth of the gear. You can use compressed air (e.g. a can of Dust-Off, etc.) to blow out the teeth. The dry filament wont be bonded to the metal (it was cold filament so it’s not melted onto the metal) … so it doesn’t take much to clear it.

I had similar issue on a Taz 6. The problem ended up being that the fans were installed incorrectly from the factory so they were not blowing ON the hot end. The labels on the fans should not be visible.