I am the proud owner of a Lulzbot Mini, and it has served me wonderfully for about a year. However, I have come across two flaws that I would like to run by you…
My first problem came when I tried to print at 50 Microns. On the Lulzbot Mini spec sheet, it says it is capable of printing down to 50 microns. However, I have had a few difficulties printing at 50 Microns. So far to improve my results, I have slowed down the printer, decreased the flow rate, increased the Z-Offset by .1 (the first layers were squished) upped the first layer height to .1mm, and given the print a ridiculous number of skirt lines (to prime the extruder). If anybody has any suggestions on how to further improve my results, I would be happy to learn! My main issue is that the extruder STILL takes a long time to start extruding anything, and when it does start extruding, the first layer is STILL squished into the bed. For the record, my bed is level (the Mini auto-levels), and my extruder isn’t jammed or clogged.
My second problem came when I tried to print Marvin. My Lulzbot Mini is generally pretty good with “torture tests” but for some reason it has a REALLY hard time with Marvin! (Picture Below)
The main problem with Marvin is his eyes and eyebrows. The lines on the eyebrows aren’t NEARLY as crisp as the other Marvin’s I have seen. The same thing goes for the eyes too. There are weird blobs hanging off of the eyes and eyebrows. Does anybody have any suggestions on how to improve my Marvin? (By the way the leg broke off, but that wasn’t part of the problem).
Any help on either of these issues would be greatly appreciated! I LOVE my Lulzbot, but being able to print at 50 microns was one of the reasons I bought the machine. In general the print quality is decent, but for some reason my machine really struggles with Marvin. Again, any help would be greatly appreciated!
I have already lowered my temperature, and increased the cooling to 100%. I also increased my first layer height to .2. Should this work? I haven’t tested a new Marvin with these new settings yet…
I am currently using nGen material (which is made by Colorfabb). As for cleaning the nozzle, is their a certain material you recommend? Should I use the isopropyl alcohol that I use to wipe down the bed? Other than that, though, I think the Auto-Leveling is working pretty good! And any minor miscalculations should have been fixed by the Z-Offset adjustments.
I as well will be trying most of the other suggestions made in this forum. Hopefully I can improve my results!
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?
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!
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!
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.
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.
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
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)
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…
