More cooling. I used a 1 meter box fan to print Marvin at 100 micron. Not joking. The 40mm layer didn’t cut it.
Skip to main content
Those are great suggestions.
What material are you using? Reducing speed a bit more can help with some issues.
Regarding the Lulzbot Mini auto-leveling, I’ve seen it cause problems and try to print below the bed surface, so some troubleshooting might be in order there. Make sure the nozzle is clean when it levels (the wiping isn’t always sufficient if the temperature is too cool).
I’ve heated the nozzle, manually retracted the filament a bit, and wiped the nozzle with folded paper or a scrubby sponge, then continued as normal with some extra skirts, and it’s helped. You can also tweak the starting gcode temperatures for better wiping based on what material you’re using or have recently used.
I’ve tried printing Marvin at 50 microns on my TAZ 4/5, and I had some success in ABS, though the edges curled so the bottom curved surfaces were a bit rough. The top was beautiful! I have yet to try PLA. I expect I can improve my results using the suggestions others have made in this thread. At the time I tried, the specs for the TAZ 4 listed 70 microns as the limit.
Ok, thanks for the clarification Tamas!
The standard print speed for nGen is 50mm/s, so I lowered it to 25mm/s (just to be safe). I’m assuming that if it prints correctly that slowly, then I can slowly speed the printer up?
Thanks for the reply!
I’m pretty sure that my tension is correct, because filament has been extruding wonderfully on my Mini (when printing at .2mm). It’s incredible that you’ve dialed in your printer so much that you can print at 25 microns! Kudos to you!
Awesome!
I would love it if you posted your settings, so we could all get some standard settings that would work! 30 Microns is really low, but I wish you could luck!
Hmmm. This is an interesting suggestion! I haven’t tried changing my nozzle yet! Which nozzles would you recommend for the Lulzbot Mini?
Thanks for the suggestions!
I have heard from numerous people that I should increase the fan and decrease the print temperature, and that is exactly what I’ll be doing! Just for reference, I’m using Colorfabb nGen, which is pretty similar to XT, except for the lower melting temp.
Thanks for the reply!
I have heard that I need to up my cooling, and it sure seems like I should take this into account!
50 microns is really sensitive printing with FDM everything has impact on it. Temperature, speed, filament etc.
As I have just read you have a 0.5 nozzle on your machine? If yes change it to 0.3 to for 50 microns prints to get good result. also recommend to use 0.4 for normal prints its a bit better quality.
The rules:
0.5 nozzle 0.3-0.1mm layers
0.4 nozzle 0.25-0.1mm layers
0.35 nozzle 0.2-0.075mm layers
0.3 nozzle 0.2- 0.05mm layers
Ok! Which .3 nozzles do you recommend for the Mini? I have never tried changing my nozzle before!
Wow! Thanks for all the detailed responses everyone! I’m sure this will all help a lot!
For those of you asking, I am printing with Colorfabb’s nGen material.
So far, I have gathered the following list of suggestions. If you have anything new or different to add, (or you disagree with one of the suggestions) please let me know!
- Lower print temperature
- Lower print speed
- Up cooling a lot!
- Change nozzle size
- Check Auto-leveling procedure
- Up first layer to .2mm
Again, if you have anything else to add, please let me know! I am so grateful that 3D Hubs has such a friendly supportive community 
Nozzle:
As I have just checked you should have a Hexagon all-metal hot end with 0.5 nozzle by default witch uses 3mm filament (hmm this could be a problem but hope it will work otherwise you have to make an upgrade to 1.75mm filament, so new hotend and extruder and new rolls of filaments)
So just look for a store in the US who sells this kind of nozzles, so you will need 0.3, 0.35, 0.4 nozzles for !!!3mm!!! filament (make sure its for the 3mm not for 1.75mm version).
Just googled and found this store (they have the 0.3 out of stock but have 0.35 and 0.4)
http://www.makerfarm.com/index.php/hot-ends/hot-end-parts.html 2
T.
Well, my print wasn’t great, but it at least completed the print. I’ll put up a photo later this afternoon, but I did learn a lot!
Speed really, really matters. Faster areas have ripples. Overhangs are problematic, as is expected. I can probably drop the temperature a little more. I can probably increase cooling a bit. I’m printing in brown ABS, so cooling is a sensitive topic.
The parts that look good look REALLY good, and the rest looks messy. I’ll probably use 50-75 microns as my finest resolution, but this experiment will help me optimize my settings.
Ah, nGen. It can be a bit tricky, but can produce good results. Lulzbot is now recommending it as a beginner filament instead of HIPS (I just spoke to them at Denver Mini Maker Faire this past weekend).
I use a scrubby sponge at printing temperature to clean the nozzle, as acetone won’t clean off PLA (it does a good job with ABS, though). I’m not sure if there’s a suitable solvent for nGen.
Keep in mind that changing the nozzle with void the warranty on your extruder. That being said, they also recommend that you use a torque wrench to install the new nozzle, and do it at a specific temperature (185, IIRC).
I’d almost recommend buying a second extruder assembly, and switching the nozzle just on that one. Still, you should be able to get acceptable results with your stock nozzle.
Yeah, I totally see your point. Honestly, I don’t think its worth goofing up my extruder so I could get better 50 micron prints. Because at the moment, I CAN print at 50 microns with decent results. So, while I may invest in a new nozzle in the future, I think I’m good for now…