In January this year I impulsively bought a second 3D printer just like I bought my first 3D printer 2 years ago. Both machines hit that magic price point of $500 which turned out to be my impulse trigger. In the two years of owning the first printer, I've had the opportunity to learn so much about the process spurring my second purchase.
Below are the two printers, the Cocoon Create (right) bought in 2016 with printed z-brace upgrades, and the new Creality CR-10s (left) purchased at the beginning of 2018. The Cocoon Create is effectively a rebranded Wanhao Duplicator i3.
Overall both printers are quite similar with a Cartesian motion system, and the ability to print the same materials at the same resolution. The big difference is the build volume, 0.0072m² vs 0.036m², the volume of the CR-10s is 5 times bigger than that of the Cocoon Create. The table below is a brief summary of the key features:
Whilst overall very similar on paper, my experience has taught me that it's often the little details that can make a big impact on print quality and user experience.
Direct Drive Vs Bowden
One key point of difference between the two machines is how the filament is fed. The Cocoon Create has the filament extruder motor at the hot end (direct drive) whereas the CR-10s filament extruder is mounted off to one side of the X-axis beam and feeds the filament through a PTFE tube (bowden) to the hot end.
By removing the significant weight of the filament extruder (approx. 250g) from the hot end, it is possible to achieve faster and more accurate prints. This is because the machine no longer has to whip a large mass side to side along the X-axis as it prints, which would otherwise cause the machine to wobble and vibrate. This effect is typically exacerbated with taller prints.
The downside of this setup is reduced feed accuracy over the length of the Bowden tube due to play, and the increased severity of filament failure which can require replacement of the entire feed tube.
Ultimately a direct drive would not be suitable for the CR-10s given it's height and construction, and the disadvantages can be easily managed for a better overall outcome.
The Cocoon Create printer has a frame made from formed sheet metal. It's a fairly simple design with the various structural pieces consisting of formed angle sections. The Creality CR-10s is assembled from 20x20 and 20x40 aluminium extrusion sections which are very rigid over short distances. The dimensional accuracy inherent in the extruded section and butt join assembly results in greater dimensional accuracy of the machine translating to better print accuracy.
Both machines are constructed in a similar fashion with a flat base and perpendicular tower. This method of construction isn't the most rigid and there is the potential for the tower to be skew. As can be seen on the Cocoon Create, a simple set of files downloaded from Thingiverse enables two lengths of threaded rod to be mounted to the machine which dramatically increases the rigidity of the frame and allows the squareness of the tower to be adjusted. It's one of the first upgrades i'll be doing to the CR-10s.
A level print bed is the single most critical part of a print setup. The Cocoon Create uses an aluminium plate with a print mat whereas the CR-10s has a slightly thicker aluminium plate with a removable glass plate on top. Having an easily removable build surface makes for easier to servicing and removal of prints. The aluminium surfaces of both machines aren't completely flat and have a tendency to warp with the heated bed cycling resulting in the need for constant re-levelling. The supplied glass with the CR-10s also isn't particularly flat, so like many other CR-10s owners, I have replaced the surface with a 300mm x 300mm Ikea mirror tile (not pictured).
I printed the same part on each machine with the same settings and material for comparison. The CR-10s print is straight out of the box with no calibration, and the Cocoon Create has the benefit of Z-braces (but not much else). They were both printed using the same natural PLA filament at 0.2mm layer height.
Both prints retain a good level of detail, with the CR-10s having greater consistency and better performance where there are overhangs, possibly due to better cooling.
The value proposition of printers has increased hugely in 2 years with the price per print volume going from $69,444/m² to $13,694/m². The increased print volume opens up so much potential making it a great time to jump in. At this price point however, 3D printing is still far from the print-and-forget functionality of the more expensive machines. It might seem counter-intuitive but the knowledge that can be gained from tinkering with a machine is immensely useful for a deeper understanding of the FDM process, and it's why I'd recommend anyone interested to cut their teeth on a DIY machine first.
The near future possibilities are tremendous, you only need to see the Creality CR-10 user group to get a taste; from printing TPU onto clothing to adding engraving lasers and printing lithopanes. All made possible because of the community and open framework that fosters creativity and collaboration.