This post is designed to help others who have the problem of cracked or damaged extruder idlers on their Lulzbot Taz 5 or Mini 3D printers. Lulzbot released a service bulletin to address this issue earlier this year. These idlers may be develop fine cracks during the assembly process due to being stressed, and eventually end up breaking. The beauty of this is that because Lulzbot is open source, it is very easy to fix this yourself. We will walk you through step by step how to replace your idler on your Lulzbot Taz 5 of Mini 3D printer:

What you need:

  • Original Lulzbot Taz 5 or Mini idler with bearing assembly
  • Hex key set (included with all Lulzbot Taz and Mini printers)
  • ABS filament (You can also use a different higher tensile strength material like nylon)
  • New Printed Idler ( Both .stl and g.code can be found on this service bulletin)
  • We recommend trying this upgraded idler designed by Shawn Overton


You will need to have a new printed idler before you begin this tutorial. If your current idler is only cracked, you should still be able to use it to print a new one. Otherwise you will need to use a different printer, ask a friend to print one for you, or have one printed through 3D Hubs.


Step 1

First, you will need to remove the toolhead. Before this make sure to unplug or turn off the machine so it is totally powered down. You can do this by first removing any filament you have loaded. Then remove the single screw and washer which holds the tool head to the extruder mount. Set this aside for when you mount the tool head again with your new idler. Finally, unplug the single connection from the tool head to the printer.


Step 2

Next, you will have to remove the old idler by taking out the single screw and washer which mounts to the toolhead. Once you have the idler off, be sure to take out the bearing assembly as well as the nut located on the inside of the old idler in the nut trap.


Step 3

Keep in mind that your new printed idler may require additional filing or sanding to ensure the bearing can spin freely inside. You will now need to transfer both the bearing assembly, and nut, to your new idler. Slide the bearing assembly into the slots for a snug fit. Place the nut into the nut trap on the inside of the idler. 


Step 4

Secure the new idler to your Lulzbot Taz 5 or Mini tool head with the single screw. Hand tighten but be sure not to over tighten as this can create new stress cracks which will lead to breakage down the road.

Note: If you went with the upgraded idler we recommended above, you will need to adjust the tension on the filament clamp as it is slightly wider than the standard idler. Turn these slightly counter clockwise to loosen and compensate for this. If you are using the standard idler you will want the space from the inside washer to inside washer (when closed) to be 5mm.


Step 6

Secure the tool head back to the extruder mount on the printer with the single screw. Finally, plug the cord from the tool head back into the plug on the extruder mount. 

Step 7

Start your next 3D print!


We hope you find this useful. Stay tuned for more helpful tutorials coming soon! Print Your Mind 3D is your official Canadian sales partner for Lulzbot 3D printers and accessories


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