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

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

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

Parts of a 3D Printer

Parts of a 3D Printer

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

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

Process Overview Design -> Print Download a model to print https://www.thingiverse.com/ https://www.youmagine.com/ https://www.myminifactory.com/ grabcad.com http://www.3dcontentcentral.com/Default.aspx https://www.traceparts.com/en https://3dx-us.com/ https://www.mcmaster.com/ https://www.digikey.com/ And others

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

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!

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

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.

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”

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.

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.

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

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

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

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

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

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

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

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