1. Things you need to know to start 3D printing at Milwaukee Makerspace
3D Printing Basics
Things you need to know
to start 3D printing at
Milwaukee Makerspace

2. The view from 10,000 feet... How the printers work
The process from design to print
Model repositories
Software
Filament

3. How 3D Printers Work Parts of a 3D printer
Print bed (with or without heater)
Extruder (melts plastic filament and squeezes it out of a nozzle like a hot-melt glue gun)
Frame – supports other parts, may include enclosure
Stepper motors, usually 4 or 5 including extruder, provide force to move parts of the printer
Controller board- the brain of the printer
Power supply – duh!
Guide rails or linear guides and bearings – provide smooth, linear motion
Belts and lead screws – used with motors to move parts of the printer

4. Parts of a 3D Printer

5. Parts of a 3D Printer

6. Parts of an Extruder Cold-end or just “extruder”
Motor mount- attaches the motor to the extruder carriage
Stepper motor- pull the filament off the spool and pushes it down into the hot-end
Connectors for cables
Hot-end
Heat-sink- keeps filament solid at entrance to the heat break
Hot-end cooling fan- keeps the heat-sink cool
Heat break- separates the high and low temperature areas of the hot-end assembly
Heater block- transfers heat from the heater cartridge to the nozzle
Heater cartridge- provides heat to melt the filament
Thermistor- reads the temperature of the heater block
Nozzle- provides a small hole for molten filament to exit the hot-end and build up the print
Print cooling fan (optional)
Improves print quality of PLA prints, especially fine details

7. Parts of an Extruder The hot-end heatsink is behind the hot-end
cooling fan

8. Process Overview Design -> Print
Download a model to print
grabcad.com
And others

9. Process Overview Design -> Print
Create a model to print: Design in CAD (mechanical parts)
Fusion360
OnShape
FreeCAD
SolidWorks
DesignSpark Mechanical
OpenSCAD
TinkerCAD
Many others (but avoid SketchUp!)
Create a model to print: Design in Modeling Software (organic forms)
Blender
Sculptris
StructureSynth
Many others

10. Process Overview Design -> Print
Design your object in CAD
Export STL, OBJ, or AMF file
Open slicer program
Import STL, OBJ, or AMF file
Tweak settings for the print, printer, and filament
Export GCODE file
Print it!

11. CAD Model -> Print: How?
A computer program called a “slicer” is used to convert the STL file exported from CAD into instructions called GCODE
GCODE tells the printer where and how fast to move the nozzle and how much plastic to squeeze out.
GCODE -> printer
computer running “host” software using USB to connect to printer
SD card, if the printer has an SD card slot

12. GCODE -> Printer
Host Software – running on a PC provides a panel to monitor and control the printer through a USB connection on printers that don’t have LCD panels with rotary encoders and SD card readers.
Pronterface
Repetier Host
Octoprint
Slicer/host combo
Simplify3D
Slic3r
Cura
Or printer specific software provided by printer maker
Note: The longer your print will take, the more likely the USB connection will experience some kind of problem.
Print from SD card when possible
Note: when using host software with controllers that have on-board uSD cards (SmoothieBoard, MKS Sbase, Duet, etc.), you must “eject” the card before disconnecting the USB cable or even turning the printer off. Failure to do so can corrupt the file system on the uSD card and create all sorts of bizarre behavior in the printer.
Note: when using a printer (CubePro) that uses host software via USB, cycling power on the printer does not reset the printer controller board if the USB cable is plugged in. If you need to reset the printer, send an @reset command via the host software, or disconnect the USB cable (see note above) and cycle power to the printer.

13. GCODE -> Printer
Printers with LCD panel/rotary encoder/SD card slot can use GCODE files stored on SD cards.
No computer and host software needed
Normally very reliable, especially for long prints
Observe proper SD card “hygiene”

14. Reliability
The most reliable way to drive a printer for a very long print is to print from the controller board’s uSD card if it has one.
File selected and print started via LCD panel and rotary encoder
File selected and print started via host software
The second most reliable way to print is to print from an SD card plugged into an LCD panel on the printer, if it has one.
Using host software to stream GCODE from the PC to the printer via USB is the least reliable way to print.

15. Proper SD Card Handling
Use low capacity cards (<=2GB)
Format with FAT file system (not NTFS)
Eject the card from the PC before pulling it out of the slot in the card reader/writer
When using host software running on a PC to drive a printer (SoM, CubePro) with a controller that has an SD card on-board (Smoothie, MKS), you must “eject” the on-board SD card at the PC before disconnecting the USB cable or turning off the printer. Failure to do so can corrupt the file system on the card and cause bizarre behavior in the printer.
In printers that print from SD cards, using a uSD card with an adapter isn’t especially reliable- use at your own risk.

16. Slicers Popular slicers Slic3r (free) Cura (free) Simplify3D ($)
MatterControl (free)
Kisslicer (free)
A few others

17. Slicers Tell the slicer about
The Printer: size, # of extruders, nozzle sizes, etc.
The Filament: material, diameter, temperatures, etc.
The Print: wall, top and bottom thicknesses, speed, fill density, etc.
Preview the sliced print
Fix obvious problems
Export GCODE (file format that printers use)
For the paranoid among you, check the GCODE file for completeness using a text editor

18. How 3D Printers Work
Prints are built up in layers of plastic squirted through a small nozzle
The plastic cools and hardens almost immediately after it leaves the nozzle
The first layer of plastic sticks to the printer’s bed that is a special material and is usually heated
All remaining layers stick to the previously printed layer
The layers built up until the print reaches its final height

19. Filament Most common types PLA Easy to print Can soften in a hot car
Use print cooling fan
Unenclosed printer is OK
ABS
Easy to print on the right printer
OK in a hot car
Don’t use print cooling fan
Usually requires enclosed printer
TPU- flexible
A little tricky to print
Most common types
PETG
OK in a hot car
Unenclosed printer is OK (?)
PVA
tricky to print
Dissolves in water/lye
Mainly used for support material

20. Filament Less common types: Polycarbonate High temperature resistant
Very strong
Glow in the Dark
Usually PLA
Abrasive- quickly ruins brass extruder nozzles
Filled filaments
Metals, glass, wood, carbon fiber
Varying properties
Often abrasive- quickly ruins brass extruder nozzles
Slicer filament settings will vary for different filaments and printers
Check the wiki for profiles
Run a test print
Ask for help

21. Filament Storage
PLA absorbs moisture from the air that will cause bubbles and ruin print quality. It also becomes brittle with exposure to moisture and UV light. Must be stored in a “dry-box”.
ABS absorbs much less moisture than PLA, but store it in a box anyway to keep it clean.
TPU doesn’t seem to absorb moisture at all.
So… best practice is to keep all filament stored in sealed bags or boxes with desiccant to avoid certain print quality problems

22. Printer Specific Operations You Need to Know
Turning the printer on and off
Loading and unloading filament
Cleaning the print bed
Leveling and Zeroing the print bed
Getting your GCODE to the printer
Starting the print
Removing the print

23. Final Note
See training materials for details about the specific printer you want to operate
they’re all sort of the same, but they’re all a little different
See presentation on print failures and their causes
See presentation on how to design parts for 3D printing