Newbie quest to get a decent print from a brand new Lulzbot Mini using Inland PLA filament

Edit: I updated the title in the hopes that this thread chronicling what I have learned in the first week I have owned the Lulzbot Mini might be of help to other newbies who get frustrated and are not sure what to do.

The TL;DR of it is don’t buy cheap filament and expect much from it, don’t implicitly trust the manufacturer’s temperature ratings, don’t restrict yourself to just the Lulzbot forums for troubleshooting tips - there’s lots of stuff that applies to all (or at least most) 3D printers, don’t give up.


I just bought a Lulzbot Mini from MicroCenter yesterday. It is my first 3D printer. I was really impressed with the sample HIPS that came with the printer, the “Roctopus” printed perfectly.

Not wanting to waste the remainder of filament, I printed the included Open Hardware Logo key chain and a wire frame polyhedron I downloaded. Both printed reasonably well. Both broke easily due to model design flaws.

Once I used up the last 14 inches of HIPS, I followed the provided instructions for loading the Inland (MicroCenter’s house brand) PLA. The label on the spool does say “Made in China” so I didn’t expect much. It was the only thing they had in stock other than ABS that was 3mm. I wanted to see just what this printer was capable of, so the first thing I tried to print with the PLA using the provided beginner high quality settings was this model: http://www.thingiverse.com/thing:1363023. It was terrible.

First of all, the nozzle had accumulated and was dragging a blob of plastic for the first five layers or so. Strings of filament were bridging between the spike and the half dome. Most of the thin walls simply aren’t there. No small details are even present - text, the slots on the edge, etc. The half dome, all the bridging and overhang tests printed wonderfully, to my surprise. I started reading the documentation and found that the included 0.5mm nozzle size might be to blame for the lack of small details. The model had parts that were meant to be measured to two decimal places! Okay fine, don’t expect any higher precision than half a millimeter, which should be more than enough for anything I will want to do in the near future.

I also noticed that the filament would just start dropping out of the nozzle while the printer was idle and at printing temperature. I modified these settings based on what I read in forums to rectify the over extrusion and oozing problems: Filament Diameter: 2.9 (based on actual measurements), Retraction Speed: 15, Retraction Distance: 2mm, Hot End Temperature: 203. That seems to have stopped the oozing and stringing for the most part.

With the new settings, I printed 3DBenchy http://www.thingiverse.com/thing:763622 next. It printed beautifully.

I know there are probably printers out there that are capable of printing in the high precision required for the first PLA model I printed, and I don’t expect that from the Mini. I’m just trying to figure out what I should expect from this printer.

So my question is this: Is there an established benchmark model, something that would be used for dialing in settings for new filaments and troubleshooting, that the Lulzbot Mini - as it is out of the box - should be able to print in any compatible filament type? Maybe even something specifically tailored to the Mini’s capabilities?

As for standard models I think most people pick something they like or reflects the type of stuff they normally print.
Cropped and rotated Benchy. I really wish manufactures of cameras and computers would agree on how to define which way is up.

Your Benchy looks good. Every filament will have little tweaks you are going to want to do. Even some for each model. I have a couple simple, fast to print STLs I use for basic filament settings to make sure I get good layer adhesion, feed rates, etc… This is one of my favorites as it’s quick, even in 0.1mm layers, and tests a few different things. http://www.thingiverse.com/thing:1023717

I find if I can print that with a new filament, I can print most models. A few things need to be changed depending on the model sometimes, but that gets me in the ballpark. Models with little islands or really small models need more cooling or other tricks like printing more than one at a time. Otherwise they can overheat and deform. The small bits on your Benchy look good, so I think you’re good there. Sometimes I change various settings based on what the preview looks like.

Note that thin walls are a big problem in most slicers. Slic3r seems to work the best for those. Simplify3D, which I like for many things, completely fails on those. Cura is hit and miss.

Frankly, Benchy is a pretty tough print. That you got good quality there, makes me think you’re doing pretty well.

If you browse the forum here, you will find lots of recommended settings for various filaments and for various slicers. Cura and Simplify3D seem to be the most common, but others are around. Just keep in mind that 3D printing and slicing is still a bit of an art, not a science. You will likely need to adjust settings for some models, particularly more detailed complex models. And some of the models out there have errors and aren’t actually printable. Sometimes the slicer can fix them, sometimes not.

Sorry about the sideways picture, I took it directly from my phone to Imgur.

What I have in mind is a model that would showcase what the Lulzbot Mini is capable of out of the box, and if this model does not turn out right, then something is wrong or needs adjusting - like a 3d printer’s version of a testing and calibration page from an inkjet printer.

I just bought this printer two days ago and I’m trying to dial in the settings for the PLA I bought. The default basic settings for PLA in Cura didn’t work all that well (see description of blobs and strings in original post), so I have no “known good settings” to fall back on, so I’m trying to establish some.

Benchy is a good standard guide. Yours is pretty good. The stringing you are seeing between the columns indicates that your retraction setting is off. Other things to check are the writing on the stern and the writing on the bottom. If you can read both of those, you are pretty well dialed in. There is a bit of heat wobble on the thinner columns, the smoke stack, etc. That may be due to cooling. You may want to increase your fan a little bit, and potentially look at adding an opposite side fan.

Thanks for the input. I decided to do an experiment with the temperature based on what I have read in the forums, specifically “A Strategy for Obtaining Great Prints” by mhackney in which he suggests printing at the lowest temperature possible. I started with the printer idle and brought the hot end to 203. Filament was practically running out of the nozzle. I decreased the temperature by 5 degree increments until it stopped oozing. It was at 175 before that happened. By the way, I’m using Inland PLA (MicroCenter’s house brand). I decided to try to print the 9 spikes model from this http://www.thingiverse.com/thing:533472 to test the stringing. I set the temperature to 185 in the settings to make sure the layers adhered. I think I should have set it to 175 or lower because it looked like a spider made a home in there…

I started with the high quality eSun PLA profile and modified these settings:
Printing Temperature: 185
Diameter: 2.9 (based on actual measurements of the filament)

I left the retraction settings alone for this test. I wanted to see what effect the temperature had first. The default retraction settings are Speed: 10, Distance: 1.5. How much should I adjust these in order to cure my stringing problem?

Update: I just finished printing the second one with modified retraction settings, and it looks as bad if not worse than the first.

Temperature: 180
Retraction Speed: 30
Distance: 2

If the last one was spider webs, this one is downright furry!

I don’t do a lot of PLA, so I might be off some here… I get strings with PETG as well, and I got rid of most of them by increasing retraction amount and speed slowly until I got the results I wanted. Increasing the part cooling fan speed and lowering extruder temp can help some as well. If you print smaller tests to dial in the temp it takes a lot less time. I like to do that, then destructive testing to make sure the layers bond well and such.

Well another test with no real results. This one used the same settings as the furry one but the retraction speed was set back to 10 and the distance cranked up to 4.

I looks about the same as the one the spider made a home in.

The temperature might be the key. Anything less than 180 and I don’t get a good first layer, if it prints one at all. However, lowering the temperature produced the most significant improvement since I started tackling this problem.

Edit: two of you suggested fan speed modification so I will try that next. I will use the same settings as the spider web one which is the best of the three I have so far so I can isolate the fan speed variable.

It looks like you are on the correct path! We usually go through about 6 to 10 kilos of filament for a specific manufacturer before we settle on a finalized profile(s.) Depending on who makes the filament, there is a wide range of formulations. We have seen PLA print anywhere from 160c to 230c depending on who makes it. These different brands will also have different ideal speeds, cooling, layer heights, layer widths, tolerances, variances, etc. (You can see our manufacturer testing notes here: http://devel.lulzbot.com/filament/) This is why we included manufacturer’s in our profiles for Cura, as settings can/will vary so much between “PLA.”

One thing to note, your retract speed of 30mm/s might be a little high. We recommend 25mm/s or slower to help prevent skipping and damaging of the gears.

Good luck with getting that fine tuned!

Thanks for the encouragement. There are several settings related to cooling. Which would have the greatest effect and how much should I adjust it at a time?

I would probably want to determine ideal temp for this filament first. Harder to cool if you are printing at way to hot of a temperature. A Temp Tower can be of great help. Keep an eye on the height, and change the temp through the control box at the desired height. This will help find the minimum temp for adhesion, and maximum temp before heat creep issues.

Once you have that dialed in, play with the fan settings. Most PLA’s like a lot of cooling, and some even benefit from a desk fan pointing to the build volume.

If you want the quickest way to help get these “strings” cleared up, go ahead and print two of these objects at once. This will give time for cooling between layers, and help reduce the strings.

Well, I was already printing at 180, and at that temperature, it just sticks to the bed. Though it makes it a lot easier to remove from the bed.

This is only my fourth day with this printer, and this is my first ever printer. I’m beginning to wonder if I am simply chasing squirrels by trying to print stuff that is beyond this printer’s capability, or more likely, I got a bad batch of filament. The included HIPS filament printed beautifully with the included profile except when I tried to print the wire frame polyhedron (strings but nowhere near as bad as this PLA). Like I said earlier, I’m just trying to figure out what this printer is supposed to be capable of.

I have read mixed reviews about Inland filament. Some say it is great, others say to avoid it like the plague. Most consistently I read that Inland has quality control issues revolving around the diameter, which I have confirmed in my own roll. I re-measured and it is now in the 2.95 to 3.15mm range. How much variation is normal for a roll of filament? Could the variation I am seeing really make that much difference?

Update: I just had a minor victory. I just completed a test on the Village Plastics PLA profile vs the eSun PLA profile.

Update #2: I later compared the two profiles using Linux’s diff command - they are identical! I’m getting two very different results from the same @%#$ settings!!! The filament quality (or lack thereof in this case) may very well be to blame.

The one on the left is the Village Plastics, right is the eSun:

Diameter variance in a single roll of filament is not normal. Good quality filament from a reputable producer may vary in size from other filament brands, but it will generally be all one size, Push plastics ABS for example tends to come in right at 2.87mm, but the whole roll is going to be 2.87 +/- .005. If your roll is varying from 2.95 up to 3.15mm, that’s a crap roll and you should throw it away and yell at whoever sent it to you.

Piercet, thanks for the advice. What brands would you recommend for PLA and HIPS?

I was under the impression that eSun supplied the filaments to MicroCenter who rebranded them as Inland. But Lulzbot’s eSun profile definitely doesn’t work for it, as evidenced by the picture above. As I said before, I got much better results with the Village Plastics profile, which surprised me.

Okay, one more experiment. I decided to remove all variables and just test the quality of the filament itself. I used the default standard / medium PLA settings for Village Plastics (eSun profile was identical). I didn’t change anything. I used the little calibration piece I used before and made six of them printed individually. Logically, they should all turn out consistent if the filament is consistent, because the same settings are being used throughout the printing process. The results speak for themselves:

All six:

The following images are in the order they were printed.
#1:

#2:

#3:

#4:

#5 (the worst one):

#6:




Again I measured 3 places on the filament about 3 to 4 inches apart and got 3 different readings. Then I just ran the filament through my pinched fingers and that was the most telling; I felt waves and bumps all long the length of the filament. This Inland PLA really is to blame for my inconsistent results.

That’s a really poor roll. I can make my own filament with better tolerance than that.

I’ve had good luck with eSun and Makergeeks filament being consistent diameter and quality. I mostly use PETG and ABS, the only PLA I’ve used is eSun and I was quite happy with it.

As long as I am printing big stuff (Raspberry Pi case), it does fine. If I try to do fine stuff (spikes test), it strings like crazy.

First half of the Raspberry Pi case turned out well, the other half looked like it was spitting out too much plastic for half the print - SAME PRINT SETTINGS! I’m convinced that the filament I bought at MicroCenter is just garbage not even worthy of putting on a weed whacker. If PLA has such low melting and glass transition temperatures, how do people even manage to ship it in the back of a non-climate controlled trailer in the summer time? (Perhaps this is the source of my problems?)

“If your roll is varying from 2.95 up to 3.15mm, that’s a crap roll and you should throw it away and yell at whoever sent it to you.” - piercet

“That’s a really poor roll. I can make my own filament with better tolerance than that.” - ttabbal

Even Lulzbot’s testing personnel had the same problems with it:
“3mm Natural PLA
Prints easily at 170-195, oozes quite a bit” (emphasis added) - esun_filament_testing_notes.odt

According to multiple sources, Inland filament is just rebranded eSun…

I have purchased a roll of Colorfabb nGen Amphora 3300.

“This material prints reasonably well over a wide range of temperatures, making it a very forgiving material for new users or complex prints.” - Brent M., colorfab_n-gen_testing_notes.odt, 12-26-2015

Sounds just perfect for me. I went to college for computer programming and I still sometimes forget the principal of “Garbage In, Garbage Out”. Lesson learned - don’t buy cheap filament!

Update: I am finally getting passable results from that weed whacker line Inland tries to pass off as filament…

I was browsing through YouTube videos to find useful stuff for later, and came across this video about calibrating extrusion rate: https://www.youtube.com/watch?v=a1vH3ge-V3Q
“Everything from model strength to surface finish is affected by this one setting. In fact, I’d say 80% of the ugly prints we see are a direct result of an incorrect extrusion rate.”

I also found this forum post: https://forum.lulzbot.com/t/lulzbot-mini-cura-overextruding-15/1913/1
I remember my Raspberry Pi case I printed badly and I thought it looked like it was trying to lay down too much plastic at a time. So I started experimenting again.

I referred back to this forum post https://forum.lulzbot.com/t/a-strategy-for-obtaining-great-prints/1326/1 from which I took the idea to be consistent and take notes. So I chose the little model that I printed six of because it would print quickly and I could change things and get results (good or bad) quickly.

My discoveries so far:

  • I may have been measuring the filament wrong, so I removed it from the printer, cut a new end, and took it off the roll and measured every third coil for about 10 feet or so. I ended up with 7 measurements and the new average is 2.93mm.
  • Absolute minimum temperature that it will come out of the nozzle: 175 C (not good for printing, no strength, prone to jamming)
  • Good minimum printing temp: 180 C (decent strength and layer adhesion, no more jamming)

Test 1 Cura Settings (basically default PLA profile with these changes):
Layer Height: 0.2
Print Temp: 175 C
Bed Temp: 60 C
Diameter: 2.93
Flow: 60%
Results: Very weak, gaps in lines of filament - not solid, filament started getting chewed up by hobbed wheel

Test 2 Settings (same as Test 1 with these changes):
Increased Print Temp to 180 C
Increased Flow to 70%
Results: Not much different from test 1

Test 3 Settings (same as Test 2 with this change):
Increased Flow to 80%
Results: Strength greatly increased - actually had to work at tearing it apart

Test 4 (same as Test 3 with this change):
Increased Flow to 85%
Results: Stringing is just visible, very strong, bed adhesion also much more noticeable, printed the spike test from earlier and it was the best yet - I could almost read the text on the bottom!

Encouraged, I printed the some assembly required tetrahedron:

It went right together with no issues whatsoever!

Further encouraged, I printed the partly assembled version:

It works!

I’m currently attempting to print that adjustable wrench with the new extrusion and temperature settings… maybe this time the screw won’t fuse to the body. That awesome platform jack may actually be within reach!