A brief introduction to 3D printing!
FDM is Fused Deposition Modeling 3D printing , one of the various methods for additive manufacturing. We use a spool of filament that is plastic based, there are different kinds of filaments one can feed to the printer. Some of them are: PLA ( based in cornstarch) , ABS ( petroleum based), conductive, flexible, nylon, TPU, hemp, stone, wood, fluorecent e.t.c We are using a nozzle of 0.4mm which is the stardand nozzle , but the machine comes with multiple nozzles.
STEP 1: There are 3 ways to obtain a 3D model :
- 3D model it with any of program (rhinoceros, solidworks,blender, openscad, fusion360….)
- Scan it
- Download it. ( thingiverse and other platforms online)
The 3D mesh needs to be in STL (stereolithography) or OBJ format in order to open it to the program for the 3D printer.
STEP 2: Install Cura on your computer and under ¨settings¨ select the printer you are going to use. (in this case we are using and Ultimaker 2+) Cura is a SLICER, which means that it is a software that will translate the 3D mesh into mechanical movement by creating the GCODE. The 3D printer does not read a 3D model but only x,y,z coordinates send to it through the Gcode for the mechanical movement. The Slicer software, it can be CURA or any other (octoprint, repetier e.t.c) is translating the 3D geometry into coordinates for the printer to move.
STEP 3: QUALITY Define you nozzle , material and then choose if you want a Fast print (0.15mm), normal Print(0.1mm) or High quality print(0.06mm) The quality is defined by the thickness of each layer, which also implies that the higher the quality of the print is, the more layers are generated and the more time it will take to print.
STEP 4: SUPPORT MATERIAL: We use support material for objects that need to have some additional parts to be printed and afterwards removed in order to secure the correct print. These are geometries that either have overhang, or that have a big angle (overhang angle) or they are ¨bridges¨with more than 4cm distance. Support material is automatically generated at Cura and there are 2 options, either to put touching the build platform ( starting from the bottom) or everywhere (also connected to parts in between the geometry )
STEP 5: RAFT- BRIM -SKIRT In order to avoid warping we use a base layer that is printed firstly either under the 3D model or surrounding it. This is a safety base that needs to be removed afterwards. The RAFT is printing a whole base underneath, the BRIM is creating outlines and you can choose the number you want , we suggest 3)
STEP 6: INFILL. Infill is the percentage of mass of the print. How empty or solid the object will be. This means that if you have a 3D modeled cube you can print in hollow or you can print is solid by changing the percentage of infill. Normal prints use 20% infill but if you are doing functional pieces it is recommended to use 100%. You can also select the type of infill ( lines, trianges, squares e.t.c) by clicking on the gear icon next to it.
STEP 7: SHELL The Shell defines the number of external walls your object will have. If you are printing something hollow you can use 4-5 wall line counts to reinforce it. Otherwise use the default setting of 3 wall lines
STEP 8: MACHINE
- calibrate build platform
- load filament and let extrude for 1 minute
- add either hair spray on the glass of the build platform ( by taking the glass out of the machine, spraying and then putting back) or use blue painters tape
- save the gcode generated from Cura at the removable SD card
- launch the file and wait there until the first layer is done to make sure everything is going ok
NOTES: In case you are using flexible filament we suggest to use a 0.6mm or 0.8mm nozzle and the printing speed should be lowered to 30 according to the parameters written on the spool box.