This section is a demo section where I show export to STL, import to Cura, export to Gcode and start a print. While doing this I discuss the following, usually based on a failed 3D-print I have brough:
A raft attaches your print to the build plate, improves stability and makes sure the bottom layer of your build goes smoothly even if it is irregular in shape. Unless I am absolutely sure I don’t need to, I always use it. If your model is well grounded to the build plate but has a complex bottom layer you could consider using only a narrow raft.
Cura or other slicing software can make printing supports automatically. It is really better to design models in such a way that they don’t need support, or make the required support yourself as part of designing the model. However, when that is inconvenient and you need support use the built-in possibility.
0.4mm is the standard size of the printer in the library. That’s medium big, so prints OK fast and with a medium resolution. Print head size can matter when you design small details on your models - a 1.0mm thick wall, for example, will print no different than a 0.8mm thick wall. A 0.3mm thick wall will not print at all. Keep print head size in mind both when designing thin structures or small details, and when resizing finished models in your slicing software!
The thicker the layer, the faster the print. However, thicker layers also produce less detailed prints. I almost always use 0.15mm layer height, which is quite thick.
Less infill means faster, cheaper prints. You can get by with surprisingly little. Even on high-tension parts like slingshots I never use more than 25%, and I usually go with 5% for non-high-tension parts.
Unless you go with 100% infill the thickness of your shell is important. As always, thinner is faster and cheaper, but too thin gets too flimsy. I usually use 1mm for high-tension parts (in practice 0.8mm-0.9mm because of print head size and layer height) and whatever Cura suggests for other parts (in theory 0.7mm, which in practice means down to 0.4mm).
I firmly belive 3D printing can come to have a positive environmental effect on how we make things. It is easy to make complex, hollow parts (that can use less material and be lighter), personified things should last longer than mass-produced ones, and we might avoid shipping raw material and partially finished produts back and forth for manufacture. That is not how it is at the moment. Some of the problems include:
Without belabouring the point, some quick tips:
https://sustainabilityworkshop.autodesk.com/blog/environmental-impacts-3d-printing has more on these issues.
This section is specific to the Ultimaker 2+ printer the library currently has.
You start the filament changing process by selecting it in the menu. It is very easy, but also documented on https://ultimaker.com/en/resources/21476-how-to-insert-filament It is important that the new filament is undamaged! Damaged filament can break off and get stuck in the feed tube. This is easy but time comsuming to fix.
https://ultimaker.com/en/resources/18767-unboxing has a “troubleshooter” section. However, talk to the library if you have serious issues.
Designing models is an iterative process. You often go several rounds with test prints before you are happy with what you have made.
Several models either require you to design supports, or make use of in-built support functions in the slicing software. A lack of sufficient supports usually botches the print.
Frequently, unanticipated problems stem from too delicate parts not attuned to print head size. If your walls are thinner than your print head they will not print. And if they just print they might be too thin for stability. Design more durable parts, change print head size or get access to another printer :-)
Imagine you print two spires side by side. As the print head travels back and forth between them it will be trailed by remains of filament, making the build less accurate. Additionally, if one fails (e.g. because the raft fails to attach the print to the build plate) it will usually cause the other one to fail as well. Though it takes more time it is usually better to print one part at a time.
I have had Cura turn fine STL files into Gcode files where some of the layers are skewed on a couple of occasions. If that happens, simply make a new Gcode in exactly the same way. Chances are, the next file will be fine.