Cracked piece above my extruder. (The idler?)

I went to replace my filament, and saw that this piece is cracked in half. I have a few questions regarding this.

I have an .stl of the piece, and it appears that it will hold in place while I can print a replacement piece, but I only print in PLA so this is all I have on hand.

Is PLA sufficient for this piece, or will it cause problems since it is close to the heat?
What kind of infill should I use for this piece?
If PLA won’t work for this, is there a replacement piece I can purchase from Aleph Objects, or do I need to find someone to print it for me in ABS?

Thanks for any help!


Did you mean to attach a picture or something? Not sure what “piece” is referring to.

If the printer is still under the Warranty period they may send a replacement ABS part as they had an issue with that part breaking. They now have an model for a replacement part that resolves the problem that might have lead to your breakage.

This same thing happened to me.
These parts are made from ABS (85% infill), which I feel is harder to print than some other Filament types like PLA.
It may require some experimentation (failed prints) to get ABS to print well - it did for me.
I always have to “enclose” my Taz with a cardboard box and Dollar Tree Foamboard to keep it warm enough.
Just remember to allow the electronics to vent to the outside.
Even a poorly printed part like the Extruder Idler Arm should work well enough until you get a “perfect one” printed.
I was able to use ABS pipe cement from HD to glue mine together long enough to print a replacement.
The glued part was pretty strong and I kept it in case I ever need it again.
PM me if you decide you can’t do it yourself and I do my best to help.

Best regards,


I will check on the warranty first because it is probably within that.

If this is a Taz 5, you might consider doing the “Combo Upgrade” at this point. The re-designed parts are much stronger and it was a fairly easy upgrade. It consists of adding a third fan (great for PLA), replacing the main extruder parts, and setting it up to do auto-levelling.

Best regards,

Mine cracked after only a few prints. I printed a replacement in PETG - seems to be fine so far after about 15 prints. Any issues that someone would see with using PETG for this part?

I assume we’re talking about the extruder idler. I went through a few of them and finally designed a heavier duty one that’s a direct replacement. I also changed the latch so that it grips and supports the idler better.

There is a new heavy duty one on the Lulzbot site too. I see no problem with using PETG, it is very strong. I wouldn’t use PLA as it is more brittle than ABS. I actually used nGen to make the prototype and I’m still using it. I did print some in ColorFabb XT and HT, but haven’t had to change it out because the nGen hasn’t broke yet like I thought it would. :slight_smile:

Is the pin that hinges the idler arm to the print mechanism seated in a sleeve or retaining nut?

My part broke as well and I was able to slide the pin, but I don’t recall seeing if I could take it all of the way out so I could use it in a replacement.

Luckily, enough of a detent remained in the recess for the idler wheel to stay in place, but I still need to print out a replacement

There was a that I had happened to see earlier.

This one is from February: