3D Slicing On The LulzBot Mini With Cura

Looking for an easy-to-use 3D slicing program with basic and expert features?

For the last week, I have been testing and, frankly, playing with the LulzBot Mini 3D printer. It is a joy to use and one of the reasons is their decision to use the open source Cura slicing software. I mentioned this relatively new software in my list of 3D slicing programs, but I want to dig in on this one a bit further.

Note: I did a quick review of the LulzBot Mini (which retails for approximately $1,350), but I also posted about 3D Printers Under $1,000 Fully Assembled, too. I'm headed over to visit New Matter very soon and hope to report back with details on their new 3D printer called the MOD-t.

When people are first introduced to 3D printing, they wonder why it is called printing at all. It is confusing since printing, for ages and ages, has been a two dimensional (2D) process, not 3D. But if you think about how an inkjet or LaserJet printer “lays” down one “layer” of ink on the page, you only have to go up or down from there – adding more layers of ABS plastic (see my post on ABS, PLA, and other materials used in 3D printing). If you look at it from that perspective, you can see how the 3D printer pioneers chose a comparison that made sense to them.

So, if you take an object and decide to 3D print it, you have to do it in layers, or, in slices. 3D slicing software is required to move your 3D object to a 3D printer so that it can “print” each layer. The program I have been using with the LulzBot Mini is Cura. Since it is open-source software, LulzBot wisely opted to create its own customized version of it, called Cura LulzBot Edition to work specifically on their printers. They created a terrific custom user manual as a PDF.

Cura is the brainchild of the Ultimaker 3D printer team and works with many 3D printers, not just Ultimaker and not just LulzBot.

Out of the box (well, there is not really a box), Cura works super well. I’m going to assume that the full version (not the forked version created by LulzBot) will work the same or better, but I’m sticking to what I am currently using. If you are new to 3D printing, it is as close to plug-and-play as I have experienced. If you need advanced features, this program is tremendous.

Some of the basic features, which you often will not need to tweak, but if you do:

  • Quality: layer height, shell thickness
  • Fill density
  • Print speed and temperature
  • Support type
  • Oh, and Quick Print options – from the main screen you can pick Low, Normal, or High Quality (increasingly longer print times, of course), which is nice.

Advanced features:

  • Quality: Initial layer thickness, initial layer line width, dual extrusion overlap
  • Speed: overall travel speed, infill speed, outer shell speed
  • Cooling: You can specify the minimal layer time, in seconds.

Then, you have an even more intense level: Expert configuration settings. You have options to turn the cooling fan on at a certain print height, or minimum and maximum fan settings. There are options to change the brim and the raft margins – raft is the layer of material under your object that increased surface area (before the advent of heated beds). Brim is similar and places a single layer of filament to keep the object on the bed, to keep the corners from lifting. But the point is there are many granular settings to help you optimize your prints.

Many slicers require you to “reslice” if you make any changes. Cura does it automatically, very quickly, and there is no reslice button.

Over at the Create Education blog, Steve Cox explains some of the finer points to how you might decide to use Cura to break apart a print job to reduce support. Support is a secondary material that helps stabilize overhanging parts of your print job from underneath. As Steve points out, you can have a lot of support waste if you just let the slicing program add support.

To get even deeper into the finer points of Cura, one of my favorite quick reads is on 3D Hubs: Tips and hints when using the CURA slicer.