1.75 mm filament with a LulzBot Mini

There are two threads on the Forum about printing 1.75 mm filament on a LulzBot TAZ with a LulzBot Hexagon Hot End (see https://forum.lulzbot.com/t/can-the-taz-5-use-1-75mm-dia-filament/1488/1 and https://forum.lulzbot.com/t/taz-5-and-1-75mm-filament/1407/1).

Wanted to share my experience printing with 1.75 mm filament on a LulzBot Mini… So far so good :smiley:

A few notes:

Hi, the manual I just read online says:

“To print with 1.75mm filament you will need to purchase a 1.75mm compatible Hexagon hot end or any other compatible hot end.”

But everywhere else I’ve read says you just change a setting in Advanced Settings.

Which is correct?

My Mini is still in the box & will be operational soon.

Thanks, kj

How are you able to use the same hotend? I thought it had a 3mm bore where the filament went in? Did you add a spacer or something?

I’d also be curious to see how this affects maximum print speed. I would think the same geared extruder motor could push a lot more plastic if it was moving 3mm filament vs 1.75

While you can use 1.75mm filament, it’s not going to be 100% reliable at all printing speeds and layer heights. If you want that level of reliability, a Hexagon hot end sized for 1.75 mm is going to be preferred.

I print with both, depending on what I’m doing. Do keep in mind that using 1.75 mm filament in any hot end sized for 3 mm filament, your results will vary.


I had try a ABS 1.75 mm on my lulzbot Mini, just changing the setting for the nozzle diameter and the first print was perfect, but later on i haven’t been able to do it again because the filamment isn’t sticking to the bed, i will change the Pei sheet and will see.

I’ve finally managed to get consistent and good prints out of my Lulzbot mini using various kinds of 1.75mm filament. Printing at normal speed and just changing the filament to 1.75mm. This was my process of trial and error until I got it working

PLA - Applied olive oil to the first 5 inches or so, prints just fine. Nothing further needed. PLA is rigid enough to be pushed through the extruder.
ColorFabb XT - Prints were 50/50 if they’d succeed, half the time it was just kinking up under the bolt. Oiled first five inches, raised temperature to 240, and bed at 70. Prints usually worked.
ABS- At first never worked. I tried oiling the first five inches and got one out of five prints to work. Tried various temperatures and they all failed. ABS is too flexible to print without some slight modification. Taking some advice from another thread on here (https://forum.lulzbot.com/viewtopic.php?f=36&t=1793&start=40), I bought some 1.75mm Bowden tube (https://www.amazon.com/gp/product/B01D1G7LRO/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1). I slipped it in the extruder from the top and pushed it down until it wouldn’t go any deeper, then marked it with a thin line where it was above the filament hole. From the line I cut it at a 45 degree angle upward and pushed it back in using the tweezers that came with the printer so the taller end was opposite the hobbed bolt. Tried printing in ABS at normal settings, just changing the filament size to 1.75mm, and it printed beautifully. Attempted an hour long print and it finished without issue. Adding the small bit of Bowden tube also increased my success rate with ColorFabb XT.