3D Printing Basics: Basic Skills for 3D Printing

The most basic skill in 3D printing is leveling the bed. It is impossible to make high-quality 3D prints with a bed that is not level.

We don't level the bed in relation to the floor, or to the surface the printer rests upon. The bed is leveled in relation to the hot end that does the printing. There is a wide variety of printers in use, but most low-cost printers use knobs or wheels at the four corners of the print bed for leveling.

This first video covers a lot of the issues that cause problems for beginners to 3D printing, including leveling the bed, setting the height of the nozzle above the surface (Z offset), and print bed surfaces and bed preparation.

Slicer software prepares an object for printing on your printer. You use the slicer to take an .STL file (a 3D representation of an object) and turn it into a set of instructions in G-code. The G-code tells the printer what to print and how to print it. The G-code is customized for both your printer and for your preferences. You open the file in the slicer, make some choices, "slice" the object into layers, and export the G-code file for your printer.

 

Slicer software can be very sophisticated, but much of this is covered by the instructions that are included with many objects, either in a "readme" file packaged with the file(s) needed for printing the object. In Thingiverse and other object repositories, there is often a set of instructions for printing in the model description.
 

A few important slicer settings to look at:

• Object's position on the print bed - Make sure that the entire object is on the print bed. You can rotate it and place it diagonally, if needed. You can also reposition the object to place one side or another upwards, depending on what you think is best. Some objects that will be put to work, like a handle for a gardening tool, may be stronger when printed in a particular position.
• Infill - Most 3d-printed objects are not totally solid inside. The percentage of infill is up to you. More infill generally equals more strength, but it uses more filament and the resulting object is heavier. Match the infill percentage to what you think the object needs in terms of lightness vs. strength vs. cost of filament.
• Layer thickness - Thicker layers mean faster printing, but thinner layers allow for great object detail.
• Nozzle temperature & bed temperature - Often specified in instructions packaged with the object. You can also check the side of your filament spool or the filament website for recommended temperatures. The nozzle temperature has to be high enough for the filament layers to bond to one another, but not too hot. The bed temperature keeps the filament from cooling too quickly and possibly shrinking or changing shape.
• Supports - Overhangs and bridges are parts of an object that don't have anything beneath them—like a dragon's outstretched wings. Without some form of support, these parts could deform or collapse while the filament is hot, especially in the first layer or two of that part of the model. Supports are printed as part of the object and are removed when printing is finished and your model is removed from the print bed.
• Fan/Cooling - Some filaments print better with cooling fans, others need only a little, and some print best with no cooling. Fan speed (as a percentage) is often part of instructions. Some slicer software allows a different setting for the first layers, if desired. Little or no cooling for the first few layers may help keep your model from breaking loose from the bed during printing.