LulzBot Mini Review: Compact, Powerful Yet Easy to Use
One of our most frequently asked questions here on the blog is: what is the ideal beginner 3D printer? While there will probably never be a single right answer to this question we try our best by reviewing printers that look like they have the potential to be great beginner machines.
One machine that looks promising in this respect, is the LulzBot Mini. This 3D printer has received rave reviews by 3D Hubs and Make: Magazine. Enough reason for us to get hold of machine to see if it really lives up to expectations.
What you will learn in this blog post:
- My experience in getting to the first print (hint: it is really easy)
- How the LulzBot Mini handles different material types
- What is great and not so great about the LulzBot Mini
- Why the LulzBot Mini is suited for beginners in 3D printing
Quick Summary for the Busy Reader:
The LulzBot Mini is the entry level machine of the LulzBot line of 3D printers. In our tests, the printer performed strongly on print quality and scored high marks due to its automatic print bed leveling feature. Points are being deducted for noise when printing and the lack of on-board controls.
- Plug and play printer
- Good print quality
- Automatic print bed leveling & great print bed adhesion
- Handles a wide range of filaments
- Community & support forums
- Noisy in operation
- No printing in untethered mode
- 3D printed printer components may need replacement over time
Aleph Objects - The Company Behind the LulzBot
The LulzBot Mini and its bigger brothers from the LulzBot line of printers are designed and produced by Aleph Objects Inc. The Loveland, Colorado, USA based company is one of the 3D printer manufacturers that is staunchly committed to the open-source movement.
This means that the hardware and software created by Aleph Objects is free to be copied or modified by all users. All software source-code, plans and material lists for each one of the LulzBot 3D printers are made available online for free. In return, Aleph Objects benefits from the improvements that the community comes up with. These are fed back into product development and incorporated into the next generation machines.
Founded in 2011 by Jeff Moe, Aleph Objects today has more than 80 employees and was on track to generate 12 million USD in sales for 2015.
LulzBot 3D printer farm. Photo © 3dprintingindustry.com
LulzBot Mini Specifications
The LulzBot Mini is a moving-bed design printer, with a direct drive extruder, a full-metal hot end, and a heated print bed. The powder coated aluminum chassis has a medium-sized foot print 43 x 34 x 38 cm that makes for a build volume of 3650 cm3. The printer has an open frame design, making it relatively light and portable with a total weight of 8.55 kg.
The machine feeds on 2.85mm filament and its open format filament system combined with its operating temperature range of up to 300°C allows it to print a wide range of materials. The build plate is made of Borosilicate glass covered with PEI print surface and reaches a maximum temperature of 120°C.
LulzBot Mini 3D Printer. Photo © Lulzbot
Connection to the PC is via USB, there Mini does not have any on-board controls or SD card slots. An interesting detail is the wipe pad at the back of the build plate which the printer uses to wipe the nozzle before starting a new print. Also noteworthy is the fact that, in true RepRap spirit, quite a few parts of the machine are actually 3D printed.
The LulzBot Mini retails for $1250, a price which is certainly towards the upper end of the scale for an entry level printer.
Here is an overview of the complete LulzBot Mini specs:
Price as tested:
Nozzle - Operating Temperature:
Heated Bed - Operating Temperature:
435 x 340 x 385 mm
17.1 x 13.4 x 15.2 in
152 x 152 x 158 mm
6 x 6 x 6.2 in
180°C - 300°C
50°C - 120°C
Cura LulzBot Edition or Slic3r
Cura LulzBot Edition or Slic3r
Windows, Mac OS X, GNU/Linux
Unboxing & Setup
The LulzBot arrived in a cardboard box with plenty of foam padding to protect it from damage during shipment. Shipped with the printer is a quick-start guide, the power and USB cable, and a handy poster explaining the key parts and features of the machine. Further, you receive a print removal knife, a flathead bristle brush, a dental pick, tweezers, a 2mm Allen wrench and five replacement wiping pads.
The LulzBot Mini ships with plenty of foam padding
The quick-start guide walks you through the steps to get the printer up and running: you first remove any remaining packaging foam then install the Cura software (more on the software below) and configure it. In the Configuration Wizard you simply select the radio button next to LulzBot Mini and you are done.
You then plug in the power cable, the USB cable and power up the machine. As a first print, LulzBot recommends that you print the rocktopus, LulzBot's mascot in the form of an octopus.
The rocktopus is supposed to load automatically the first time you run the software. This was not the case for me such that I downloaded it here. With all the necessary preparation in place it was time to heat up the print head and get down to melting some filament!
Printing the rocktopus - LulzBot's mascot
Here are a few more impressions of the LulzBot and some of its 3D printed components:
Loading the Filament
The LulzBot Mini ships with a tiny bit of HIPS filament left over in the tool head from quality control. You need to remove this before proceeding to your first print. In order to do so, you heat the hot end to 240°C using the Printer Interface window. You then release the hinged idler by compressing the springs that hold it in place. This releases the filament which can now be pulled out of the tool head.
To install a new filament spool, the filament holder is flipped into an upright position which secures it to the frame of the printer. You then simply slide the filament spool onto the filament holder and push the filament into the feed hole until a small amount of molten material comes out of the tip of the nozzle. The filament is then secured by snapping the hinged idler back into position.
Changing filament on the LulzBot is easy, you sometimes just have to fumble a bit to get the filament into the feed hole. You can't really see the feed hole well as it is somewhat hidden behind the hobbed bolt idler.
Changing filament: the filament feed hole is a bit hidden behind the hobbed bolt idler.
Note: the Lulzbot Mini ships without any filament. You need to order this separately when buying your printer. Interestingly, Lulzbot recommends HIPS filament. This is somewhat surprising as HIPS is not that commonly used as primary printing material. Being soluble in limonene, HIPS is typically used as wash-away support material rather than a stand-alone material for complete prints.
For beginners I'd recommend to start with PLA as HIPS can create issues with layer adhesion and cracking. But, I am getting ahead of myself, more on materials is coming below.
Build Platform Leveling
The LulzBot makes print bed leveling a breeze since the automated bed-leveling sequence takes care of it for you. When launching a print, the printer will first start heating the print head to 160°C, then wipe the nozzle clean before probing the bed-leveling sensors. Once that's completed the tool head moves into a holding position waiting for the print head to hit the desired printing temperature. At the moment that's reached, printing begins.
The nozzle homing in on one of the bed-leveling sensors during the automated bed-leveling sequence.
The total start-up sequence takes around four minutes. As great as the automated bed-leveling is, it also get a bit annoying over time as the printer always rigorously follows its routine. If you need to stop a print during the first layers and want to relaunch it immediately afterwards, it can't be done. The machine will first cool down, wipe the nozzle, re-probe the bed-leveling sensors before setting off on a new print.
Host Software & Slicer - Cura LulzBot Edition
In line with their open-source philosophy, Aleph Objects has chosen open-source Cura as their host and slicing software. You do however get a LulzBot flavoured version called the Cura LulzBot Edition.
I downloaded the latest version of the software from here. I installed it without any issues other than the fact that the interface came in German. Now, this is probably due to the fact that I run a German version of Windows. I'd still have liked the option to switch it to English rather than the software making that decision for me. As a side comment, the German translation of the different slicer settings is not complete as some are still shown in English.
Any user of Cura will recognize the familiar settings, the interface just appears in the brand specific lemon-green tinge and the software is pre-configured for the LulzBot range of 3D printers.
There is not that much to be said about the Cura LulzBot Edition. It works with the same advantages and drawbacks as the regular Cura. For a beginner it is certainly helpful to start off using the Quick Print settings. Once you get a bit more experience though, it pays to switch to Full Settings which give you more control but also require a bit more knowledge. If you really want to dig into the advanced settings, I'd recommend that you download the user manual which describes each slicer setting in quite some detail.
Cura - LulzBot edition (click to enlarge)
For the more advanced users it might be interesting to know that I also ran the LulzBot Mini using the Simplify3D software (a premium, closed-source slicer and host software package). This worked perfectly fine, the Mini's startup sequence with wiping, preheating and auto-leveling was included out-of-the-box. There was no need to manually paste this into the g-code.
All in all, the LulzBot comes pretty much plug and play. It was a real pleasure to unbox and set up the machine. Without a doubt even a untrained beginner can be up and running in a few minutes only. The quick-starter guide is well illustrated and provides clear step by step instructions, I fail to see how one could go wrong by sticking to it.
The machine control panel within Simplify3D (click to enlarge)
LulzBot Mini - The First Prints
At the time when I started working with the Mini, Halloween was approaching. Thus, I decided to throw it in at the deep end and see how it performed. Let me explain: I typically start off by testing a printer with PLA, a material that is comparatively easy to use. In this case, I had a spool of glow-in-the-dark ABS laying around which I had tried unsuccessfully on another printer before.
I was very quickly impressed by how well the LulzBot handled the ABS. It churned out print after print without the slightest hiccup. The prints stuck to the bed, not a single one came lose nor did I experience any warping.
See for yourself:
Skull - 3D printed with glow ABS
Here are a few more impressions of the first prints that I ran:
LulzBot Mini - Printing Performance
To gauge all aspects of the Mini's printing performance, I used the test protocol from the Make 3D Printer Shootout. Printing the same probes on different printers allows me to compare performance between different machines.
All tests were run using PLA, at a print speed of 40mm/sec and at a layer resolution of 0.2mm. The probes are then evaluated on a scale of 1 to 5 with 5 being the maximum score.
Here is how the LulzBot Mini performed on these models:
The dimensional accuracy probe measures how much backlash a printer produces. The probe consists of six super-imposed discs, each with a decreasing diameter. Once the print is completed, the diameter of the second disc from the bottom is measured. This has a target diameter of 20 mm, the Mini's probe showed deviations of no more than 0.2 mm. Score: 4/5.
The bridging performance test is designed to probe a 3D printer's ability to surmount distances without support material. The probe has five distances to be bridged, ranging from 20 mm to 60 mm.
The LulzBot dropped a couple of perimeters on the 4th and 5th bridge. A good but not a perfect result. Score: 4/5.
The overhang performance test simply measures the angle at which the printer starts struggling with completing overhangs. The probe has four angles at 30°, 45°, 60° and 70°. The LulzBot managed the 30°, 45°, 60° and 70° angles to perfection, without any drooping perimeters. Score: 5/5.
Negative Space Tolerances
The negative space tolerance test is a measure of a printer's ability to create fine negative (or empty) spaces making sure that two separate parts of a model don't fuse together where they aren't supposed to. The probe is a block with 5 pins, each with a decreasing negative space around it ranging from 0.6 mm to 0.2 mm. The number of pins that can be removed at the end of the print determines the score.The Mini displayed an average performance, only 3 out of the 5 pins could be removed. Score: 3/5.
Fine Positive Space Features Performance
The fine positive space features test essentially gauges a 3D printer's retraction performance. The probe is a plate with 6 conical spires that thin out towards the top.
The LulzBot managed to complete the spires but with some connecting filament strands. Score: 3/5.
Mechanical Resonance Test
Two of the test probes measure the mechanical resonance in the XY gantry and the Z axis respectively. As resonance is difficult to measure quantitatively, this is a binary test which means that the test probe is either assigned a „pass“ or „fail“.
Mechanical Resonance in XY
The XY-resonance probe turned out fine: there is no noticeable rippling at the corners nor at the inset of the print wall. Score: 2/pass.
Mechanical Resonance in Z
The CraftBot mastered the Z-resonance probe without any issues. The result shows a uniform layer pattern that does not change anywhere along the entire height of the probe. Score: 2/pass.
Articulated Makey Robot
The articulated Makey is an extremely challenging print that combines many elements of the above performance tests into a single probe. The articulated limbs have a gap of just over 0.3mm while the arms have overhangs of 65°, a challenging print for any 3D printer.
The robot produced by the LulzBot Mini turned out good but not perfect: the limbs did show some signs of having fused with the body of the robot. While I managed to pry all of them loose, this seems to confirm that the machine has some issues with handling negative spaces.
Head and body surface: some ringing is visible around the large "M" on the front of the robot's body. The head also has a couple of smaller blemished as the printer did not manage to completely close the top of the dome and also left a small gap in one of the eye sockets.
Curved head surface: Score: 3/5.
Body surface: Score: 4/5.
Here are a few more impressions of the Mini in action:
Using Materials other than ABS
Obviously, I printed a lot more than just the Make test probes on the LulzBot. I tried to print a mix of practical and decorative prints, in a variety of materials, to learn more about the strengths and weaknesses of the machine.
Printing with PLA
As described above, contrary to my usual way of proceeding I only started using PLA after I had used ABS. As expected, the LulzBot handles PLA well, a moderate print bed temperature of 50°C makes sure that prints stick fine.
I did run into an issue though that is indirectly related to PLA. Read more on that further down.
Printing with CorkFill
CorkFill is a PLA/PHA filament compounded with cork dust, produced by ColorFabb. Following the manufacturer's advice to increase the flow rate by +5% and having tweaked retraction a bit, I was able to get prints with a really nice surface finish. I experienced absolutely none of the nozzle clogging that can come with printing wood based filaments.
Printing with nGen
Just as I was testing the LulzBot, ColorFabb come out with a new co-polyester called nGen. I was able to secure a sample just before the product launched put it to the test.
I got some really great results using nGen which is both testament to the print quality of the LulzBot and the ease of use of nGen. I found that nGen worked well when printed at 235°C, the print bed at 75°C and at a speed of 40mm/s. Read a more detailed review of nGen here.
Printing with NinjaFlex
With the LulzBot Mini having a direct drive extruder, I was keen to see how well it would handle flexible filaments. While the printer managed the first few layers well, all my attempts to print with flex filament failed at some point. Even at very low printing speeds, the filament would buckle eventually, thereby preventing the extruder from being fed properly.
Note: in October 2015, LulzBot brought an new extruder to the market. The so-called FlexyStruder is specifically designed to enable the Mini to work with flexible filaments such as NinjaFlex and SemiFlex. The FlexyStruder tool head has a thicker extruder body and a 0.6mm nozzle allowing for fast and reliable prints with flexible filament.
The optional FlexyStruder tool head makes the LulzBot fit for printing with flexible filament.
A Couple of Other Observations
Wear & Tear on 3D Printed Parts
One thing I noticed after using the Lulzbot for a while was a fine layer of of dust around the top of the tool head. Taking a closer look, I realized that this were material particles stemming from the drive gear. As you can see from the below picture, the edges of the drive gear wear out over time and the drive gear will need replacing at some point.
The drive gear showing signs of age.
Towards the end of my test, after many hours of printing, I also noticed that the block which holds the idler retainer screws had cracked in two places. While the printer was still working fine, this also needed fixing since this part plays a critical role in putting tension on the filament in order for it to be fed into the extruder properly.
The upper part of the tool head developed some cracks after many hours of printing.
Now, fixing these issues is not that difficult since the LulzBot is an open-source printer which means that all the production parts can be downloaded and re-printed. Still, the 3D printed parts are the weakest components of an otherwise solidly build machine.
A clean metal surface on the nozzle is critical for the automated bed-leveling process to be successful. Therefore, the printer always first wipes the nozzle on the wipe pad before proceeding to probe the four bed leveling sensors located on the edges of the build plate.
I had a couple of cases where the bed leveling failed quite badly: when autoleveling, the nozzle did not seem to recognize when it hit the bed-leveling sensor and kept pushing downwards, bending the print bed. Searching for a solution in the LulzBot forum, I came across a few threads where users complained about this very issue.
The forum did also provide the solution: the problem stems from a nozzle that is not properly cleaned during the wiping process. The solution lies in increasing the cleaning temperature of the nozzle. I simply edited one line of gcode whereby I increased the temperature from 160°C to 170°C. This settled the issue.
Thinking about when these failures had occurred, it was each time when I was printing with PLA. Due to PLA's lower printing temperature, the relative temperature during the nozzle wiping process is also lower. In other words, it is not sufficient to properly clean the nozzle which then fails to make contact with the bed-leveling sensor. So this is a problem that can get solved with a simple tweak but judging by the Lulzbot forum this is something that quite a few people are struggling with.
That being said, during all the time where I worked with the Mini, I had not one single failed print due to delamination which proves that the combination of the print bed leveling and the heated print bed works perfectly. A huge plus for the machine!
- A complete package: the Lulzbot Mini is a complete package that delivers straight out of the box. The printer is very much plug and play, something many manufacturers claim but few really deliver.
- Ability to handle a large variety of materials: one aspect of the LulzBot that I really love is the fact that it works so well with a wide variety of filaments. The operating temperature range of both the hot end and the print bed is wide enough to cover materials from PLA to Polycarbonate. Another big plus is the open format filament system which guarantees you the freedom to explore materials from all kinds of different manufacturers and doesn't lock you into having to buy your replacement filament from a single source.
- Print bed-leveling: despite that snag that I ran into with the auto-leveling print bed, this still is a very strong feature of the printer. Anyone with a bit of 3D printing experience knows that a good print starts with a perfectly level build plate. God knows, I have spend countless hours trying to level print beds manually on various printers. With the LulzBot Mini that is all taken care of, an advantage not to be underestimated, especially for beginners.
- A strong manufacturer & community: Aleph Objects is a company with a track record and one that's likely to be around for the foreseeable future. LulzBot machines have performed consistently in various 3D printer tests over the years and the company keeps on developing and upgrading their product line. Further, there is a strong LulzBot community. Just go and take a peek into the forums, you'll find many fellow LulzBot owners that are very willing to help with any questions or problems that you may have.
- Noise levels: the LulzBot Mini is quite a noisy printer. Like many of the 'desktop' 3D printers, you don't really want it to be sitting on your desk, printing, while you are trying to concentrate on something else. Given that you cannot print in untethered mode, the printer must be closely located to your PC and you have to deal with the noise.
- Build volume: as its name indicates, the Mini is limited in size which also means that it has a build volume that's not huge. I had to scale down a few prints in order to fit them on the print bed. Still, unless you plan to continuously print very large items, the build volume is an acceptable trade-off in view of everything else you get with this machine.
- Wear & tear of 3D printed parts: on the machine I tested, some of the 3D printed parts showed signs of wear. Now, the good news is that you can print your own spare parts but then you also need to be comfortable with dissembling the printer to fit them. It would certainly help if the 3D printed parts were made from a material other than ABS; nylon which more durable seems like a better alternative.
With the LulzBot Mini, Aleph Objects had made a very solid extension to their product line. While the company may historically have been known to produce machines that appeal to hardcore Makers, the Mini is a 3D printer that will appeal to beginners and Makers alike.
With its ease of operation, reliable print results and flexibility in filament choice, the LulzBot Mini makes for a great 3D printer. If you are looking for buy your first 3D printer, the LulzBot Mini should be on top of your prospect list.
LulzBot Mini Review - Summary
A well-designed, entry level machine for the 3D printing enthusiasts who can afford to spend a bit more money. Quick to install and reliable to operate, the LulzBot Mini appeals to a wide audience from hobbyists and designers to schools and libraries. Comes with the flexibility of an open-source machine and processes a great range of filaments.
While not error-free, the automatic print bed leveling eliminates a lot of the first layer woes, a distinct plus. The lack of on-board controls and the noise levels are the only drawbacks of the machine.
If there are any fellow LulzBot Mini users reading this, I'd be very interested to hear your thoughts and opinions. Feel free to leave a comment below!