With the Lulzbot Mini 3D printer, an open source philosophy and a great user experience don’t have to be mutually exclusive. Thomas Sanladerer explains why.
Note: This review originally appeared on Thomas Sanladerer’s YouTube Channel and is subject to copyright. Text and images have been reproduced with the author’s permission.
I like how 3D printers are moving forward — and that’s doesn’t only refer to bigger, hotter and fast. So today we’re going to take a look at the Aleph Objects Lulzbot Mini.
Aleph Objects isn’t exactly a new player when it comes to 3D printers — in fact, they were already around when the hobbyist 3D printers were still mostly RepRap, as in “self-reproducing machines with mostly 3D-printed parts”.
The Lulzbot Mini still carries those genes — which you can clearly see in the fact that there are still custom 3D printed parts in here everywhere aside from standard parts and the frame, and I like that — functionally, they’re not any worse than molded parts, but with these printed parts, you also get the ability to modify them in whichever way you like and just reprint them.
Now, how does Aleph Objects manage to print this many parts for each 3D printer they sell? Well, for one, they do still have that world record printer farm of 109 Lulzbot TAZ printers doing their thing non-stop, so….
The other thing that Aleph Objects is really big at is being open-source and not only releasing the design files for their products, but also actively supporting the free/libre projects that their (and most other) printers are based on — everything about the Lulzbot printers is open, accessible and free for you or anyone to use and modify.
That spirit is getting somewhat lost with more and more printer manufacturers pushing into the market, but I think it’s still really important to share and make accessible how you solve the challenges you run across. So, yeah, right there, huge thumbs up for Aleph Objects already.
Lulzbot Mini Features
So to get to the actual printer and it’s features, the Mini is actually what I’d call a “compact class” printer with a slightly bigger than 15 cm or 6 inch cubed build area.
It’s got a heated bed based around a borosilicate sheet of glass, with PEI tape for adhesion, and a silicone heater. There’s an all-metal Hexagon hotend with a .5mm nozzle, which is also used for auto-tramming the bed, more on that later.
What else? Well, it’s based on a metal frame, uses IGUS bushings and drag chains and, overall, does look like a very, very well-made printer. And that pays off. The user experience I’ve had with the Mini has been as close to perfect as I’ve ever experienced.
It comes pre-assembled and pre-tested, which means that the entire setup process is basically just take it out of the box, plug it in and start printing. This is the first print I got out of it, using the included sample filament, printed on medium quality, and it does already look very decent.
Custom Cura Software
The two big big factors that work together for this to work that well, are for one, there’s a USB thumb drive included that contains the firmware’s source code, design files, a few 3D model and a branded version of Ultimaker’s Cura that is ready to rock out of the box, so you don’t have to go hunting around for the right software version.
It’s basically a skinned, green version of the classic Cura, and it includes profiles for ABS, HIPS and PLA, each in three quality grades. I’ve tried almost all of them and they just work. I wasn’t even tempted to start tweaking Cura’s settings after I had finished the first pound of filament with the Mini.
You can use also use the stock Cura 15.04, mind you, but not 15.06, that one doesn’t yet support any printers other than the Ultimakers. With stock 15.04, you also get the predefined printer profile and print settings, this time for ABS, PLA and PET with an additional “Ulti” quality setting.
But for both the stock and skinned Cura versions, you also can download a plethora of predefined profiles for the Mini for basically any material you could think of, and based on those profiles, you can also use Cura’s expert mode and tweak the settings as much as you want.
Overall, that’s a really nice tradeoff between ease of use — I mean, it doesn’t get any easier than Cura’s simple mode — and versatility. I do love Cura for it’s clean print results, speed and simplicity, but if you, for example, need a specific feature from Slic3r or any other “standard” slicer, there’s nothing stopping you from using those, either.
Bed Setup is Lots of Fun
Now, the other thing that makes this printer fun to use, and I was actually really enjoying printing things again, because it’s not this huge apparatus you have to operate to get a print out, that other thing is the entire bed setup.
I think I’ve mentioned it before, but I don’t see why you wouldn’t want some sort of auto tramming compensation thing going on and would rather fiddle with something like this, so I was pleasantly surprised when I found out how the Mini handles it.
Now, typically, you have some sort of sensor or probe or whatever that actively probes the bed in a few spots. If you look at the Lulzbot Mini’s carriage, there no such thing as a probe or sensor. So the way the bed is measured works like this. There’s four metal shims or washers at the corners of the bed that hold the bed down onto these Ninjaflex spacers. Then there’s the all-metal hotend that slams into, or more precisely, gently touches each of those shims. And that’s it!
When the hotend touches down, it closes a circuit between the hotend itself and the bed carriage, and that’s basically used as an endstop by the firmware. Because these are precision machined washers, the firmware knows exactly how far further down the bed is going to be, and uses the best fit between those four points to estimate where it should start printing.
Of course, having four mounting points isn’t ideal, but with a bed this small and the flexible spacers underneath the bed, this works so well that you’d be hard pressed to tell if the bed tramming was meticulously adjusted by hand or simply compensated for in software, like the Mini does.
Again, the fact is, it works, perfectly, each and every time, and it takes out the challenge of mounting the sensor with a specific offset and then adjusting that again in software — it’s just another spot that is made easier and more fool-proof, and that’s always a good thing, right?
So for this to work, the Mini comes with a specific start-up procedure, again, that’s also included in the Cura profiles. It first homes itself towards the top, then waits for the hotend to cool down far enough, and then… well, it cleans its nozzle.
Any small bit of plastic residue could cause issues with the autotramming procedure, but with that extra cleaning pass, I’ve not had that fail a single time. It uses a small replaceable strip of hard-foamy-type-stuff that does last for a good while — I’d say one side easily lasts for two kilograms of filament — then you can flip it over and use the other side. It also comes with five replacements, but if you ever need more, you can also buy them separately from Lulzbot.
Quality and Convenience
And this kind of convenience or, how do put this, the quality feel, reliability, the love of detail, that is apparent throughout the entire printer.
First off, drag chains. I love seeing them, I know they are ridiculously expensive to add, but make the entire wiring just so, so much more professional than just having a dangling bundle of wires. But Aleph Objects went one step further and are also using cable tubes (I don’t know if that’s really what they are called) for the wires anywhere they aren’t moving. Big plus for reliability and looks there.
Then there’s the Hexagon hotend. I hadn’t used that one before, but it works perfectly for ABS, HIPS and, most importantly, PLA, which are the three plastics I tested this printer with. Even at twice the speed of the stock 50 millimeters per second, it kept up nicely.
And then there’s the electronics compartment, and at this point, seeing all these pretty parts in here didn’t really surprise me. At the core of it all, there is an Ultimachine Mini Rambo, a Delta power supply, so an actual high-quality, brand-name unit. It’s nice to see that, as most other manufacturers are using no-name Meanwell clones. And there’s these huge ferrite cores on the mains input and on each motor output, which should take care of any stray electromagnetic interferences, those can cause some super hard to track issues, especially with the endstops.
One more thing that struck me during the unboxing was the handle or grip area. Because it’s not something a rookie manufacturer would even think about putting on there; it’s not a feature you can even put on the spec sheet, but it’s there and I love it! The exact same handle would also fit really well on the Printrbot Play in the same spot, and I might just print one for it. After all, the files for these parts are all out out there.
So those were basically all the things that the Mini has and does well, but there are a few minor things that could still be improved.
One is that it feels weird not to have an LCD control panel and SD reader at this price point. Again, you can easily add one, and I don’t typically use one myself because I prefer OctoPrint on a networked Raspberry Pi. So, coincidentally, two of these unused mounting holes match up perfectly with the ones on a B Plus model. Go figure….
The other thing is that, at least for my unit, the nozzle was set a good bit too low, so low that the first few millimeters of each print would get smooshed down too much and just bulge out to the sides. According to Aleph Object’s support team, that is on purpose to help with bed adhesion, which i find a bit hard to believe, since a) that nozzle was set much too low and I still get good adhesion when I raised the nozzle by .15 millimeters or almost half the layer thickness of the first layer; and b) bed adhesion is epic anyways with that PEI tape. PLA and HIPS stick just perfectly and peel off nicely when cold, while ABS did stick a bit too well and often required a fair amount of force to get off the bed.
And here’s another nice feature of the Mini: After a print, it drives the bed all the way to the back and then waits for it to cool before it moves it back towards you to indicate it’s now cool enough to touch and to remove the print. Which is much easier when it’s cold.
And one more note on size. Six inches is plenty. Of course, it’s not going to satisfy those users who are continuously going for those monstrously large parts, but it’s a nice tradeoff size that, most of the time, is going to be more than enough. It’s also much easier to handle when it comes to warping and such. And the small size also allows the Lulzbot Mini to move and accelerate faster, which means it will finish faster and give you cleaner results on the rim of a part with pointy corners.
Pricing and Conclusion
So, as far pricing goes, the Lulzbot Mini is 1.350 US dollars with free shipping, and if that seems expensive for you when compared to one of the much larger Prusa i3 kits, admittedly, it kind of is. But if you compare it to the somewhat similar Ultimaker 2 Go, well, then you’re in about the same ballpark.
I’d personally say that the Mini is very much worth it’s price, especially considering that you’re supporting something that’s truly open source, and getting a printer that is definitely a premium machine. And you can even buy it on Amazon with one-day shipping if you’re really desperate for it!
So those were my impressions on the Lulzbot Mini, what I’d like to know from you guys and girls is whether you personally care if a printer or any other product is respecting the Open Source spirit.