REPRAP 3D PRINTER 101 BY RCJOSEB What is it? What does it do? How does it work? Why choose a RepRap? Speak 3D

What Is a RepRap? REPRAP pronounced REP-RAP stands for Replicating Rapid Prototyper. Started in 2005 by a senior lecturer at the University of Bath in the U.K. as an Open Source/Design project. Printer can replicate its own parts.

RepRap 1.0 "Darwin" February 2008

RepRap 2.0 "Mendel" October 2009

RepRap 3.0 “Huxley" August 2010

RepRap “Prusa i3”

RepRap “Prusa i3 Rework”

RepRap “SmartRap”

What Does It Do? Melts PLA (Polylactic Acid) or ABS (Acrylonitrile Butadiene Styrene) layer by layer onto a printing surface (glass, PCB, etc.) to form an object.

How Does It Work? PLA or ABS in a “string” form is either pulled or pushed through a heating element onto the printing surface. Software called “G Code” controls the movement of the motors that move the heating element along X, Y and Z axis. Think of a fancy hot glue gun.

Why Choose a RepRap? Open Design. All plastic parts can be obtained on GitHub and printed so you can either create another printer or repair your own. Uses standard metric screws, nuts, bolts, rods, pulleys, etc making repairs, enhancements easy. Strongly supported by the 3D printing community. Low cost compared to other brands.

3D hardware printing terms you need to know. Speak 3D - Hardware 3D hardware printing terms you need to know.

X Axis The sideways (left to right/right to left) movement of either the printing bed or the print head.

Y Axis The back and forth (front to back/back to front) movement of either the printing bed or the print head.

Z Axis The up and down/down and up movement of either the printing bed or the print head. Most common is the up and down/down and up movement of the print head.

The material that is used for printing. PLA ABS Chocolate Others Filament The material that is used for printing. PLA ABS Chocolate Others

Print Head May or may not contain an extruder. May or may not contain a fan. Holds the hotend in place.

Extruder There are two types of extruders: A “Wade” type extruder users a motor, bearings, gears and a “hobbed” bolt to PULL the PLA or ABS into the hotend. This extruder is part of the print head. A “Bowden” type extruder uses a motor, bearings and gears to PUSH the PLA or ABS through a PTFE tube into the hotend. This extruder is not part of the print head.

Hobbed Bolt An M8 sized bolt that contains gear like cuts. Used to “grab” the PLA or ABS in a Wade Extruder so that it can be PULLED through the extruder.

Hotend Melts the PLA or ABS as it passes through its tip. The tip usually consists of a metallic nozzle attached to a metal heat sink that is then heated by either a ceramic tube or a resistor. The middle section contains another heat sink that can be cooled by a fan. The other end is often called a coldend and may contain a PEEK insulator. Temperature is monitored by the use of a thermistor. Various types, i.e. Jhead, Genie MK2, E3D, Huxley, etc.

ColdEnd Upper portion of the hotend. Portion of the hotend where the PLA or ABS enters. Does not get hot so it does not melt the filament. May contain an extruder. May contain a heat sink. May be covered by a PEEK insulator. May be attached to a Bowden (PTFE) tube.

Short for Polyether Ether Ketone. High resistance to heat. PEEK Insulator Short for Polyether Ether Ketone. High resistance to heat.

Bowden Tube (PTFE) Short for Polytetrafluoroethylene. May be used to insulate the PLA or ABS while it passes through from the coldend to the hotend. May be used to guide the PLA or ABS from the Bowden Extruder to the coldend of the print head.

Hot Glue Gun Comparison

Print Bed Surface that the 3D printer prints on. Made of glass, carbon fiber or PCB. Borosilicate glass is best instead of plain glass. Referred to as a Heat Bed when heated. Heated Bed used mostly when printing with ABS.

Borosilicate Glass Made with silica and boron trioxide. Expands less than plain glass when heat is applied. Less resistant to thermal shock and stress.

Heated Bed (PCB) Made from the same material as Printed Circuit Boards and heated by the use of a resistor. Must be etched directly from 35um copper clad to ensure even heating. Usually placed below a piece of Borosilicate Glass. Printing on a heated bed allows the printed part to stay warm during the printing process and allow more even shrinking of the plastic as it cools below melting point. May be used for PLA as well.

NEMA 17 Stepper Motor Motors move in small increments vs just spinning. 1.7 x 1.7 inch (43.2 x 43.2 mm) face plate. Most popular brand are: Kysan 1124090/42BYGH4803 Rattm 17HS8401 Wantai 42BYGHW609

GT2 Pulleys and Belts Attached to the Nema 17 stepper motors and used to move the printing bed and printer head along the X, Y and Z axis. Available in various sizes and number of teeth, Have a rounded tooth to help prevent backlash. SmartRap uses a 20 tooth pulley and belt.

Smooth Rod Sometimes referred to as drill rods. Various metric diameters and lengths. Used as part of the frame in some 3D printers. Smooth with no threads to allow for bearings. Used with bearings to move the printed ned and printed head along the X, Y and Z axis.

Threaded Rod Look like very long screws without a head. Various metric diameters and lengths. Used as part of the frame in some 3D printers. Used with nuts to move the printed ned and printed head along the X, Y and Z axis.

LMU Bearings Referred to as Linear Motion Bearings. Attached to print beds and other printed parts to allow for movement along the X, Y and Z axis. Designed to provide free movement in one direction, usually along the length. Available in various metric sizes.

608ZZ Bearing Referred to as a Radial Ball Bearing. Designed to provide free movement around an axis instead of along it as in skateboard wheels. Available in various metric sizes

R.A.M.P.S Latest version is 1.4 Acronym for RepRap Arduino Mega Pololu Shield. Includes plug-in stepper drivers and extruder control electronics on an Arduino MEGA shield for easy service, Interfaces with an Arduino MEGA 2560 board.

Arduino Mega 2560 Latest version is R3. Microcontroller board based on the ATmega2560. Compatible with most shields designed for the Arduino Duemilanove or Diecimila. 54 digital input/output pins (of which 15 can be used as PWM outputs) 16 analog inputs 4 UARTs (hardware serial ports) 16 MHz crystal oscillator, USB connection Power jack ICSP header Reset button.

Polulu Stepper Driver Controls a stepper motor. Comes packaged in a pluggable module that makes for easy installation or replacement. Most common models are the A4988 and DRV8825. A4988 offers a max step resolution of 1/16. DRV8825 offers a max step resolution of 1/32.

3D software printing terms you need to know. Speak 3D - Software 3D software printing terms you need to know.

CAD Acronym for Computer Aided Design. A software program that is used to design a 3D object: FreeCad (Open Source/Free) OpenSCAD (Open Source/Free) and TinkerCad. TinkerCad (Online /Free) TinkerCad my favorite so far: Easy to use. Nice tutorials.. Writes STL files.

STL Files Acronym for Standard Tessellation Language. Used for rapid prototyping a.k.a. 3D printing. STL files describe only the surface geometry of a three-dimensional object: Without any representation of color. Without any representation of texture. Using triangles.

Slicer Applications Convert STL files into G-code. G-code is created by slicing the 3D object into layers. G-code is read by the 3D printer. Most slicer applications are Open Source: Cura Slic3r Repetier Host

G-Code A language which instructs computerized machine tools on how to make something. The “how to make something” is defined by instructions on where to move, how fast to move, and through what path to move.

Firmware Firmware is flashed and stored onto the Atmega 2560 processor. Just like a PC BIOS tells a computer how to run and accept commands, firmware does the same thing. The are several different firmware available for the RepRap 3D printers but the most popular are: Marlin Repetier Teacup I plan on using Marlin.

Speak 3D – Printing Terms 3D software printing terms you need to know.

Skirt A Skirt is an outline the surrounds your part but does not touch the part.   The skirt is extruded on the print bed before starting to print your model. Skirts serve a useful purpose because they help prime your extruder and establish a smooth flow of filament.

In Fill The material used to fill the empty space inside the shell of an object. Measured by percentage An object printed at 100% infill will be 100% solid. More infill will make an object stronger, heavier, and slower to build. Less infill is lighter and quicker to build. Infill can be achieved using different patterns: Grid pattern Hexagonal or other geometric patterns. Use less infill on test objects and prototypes that wont be subjected much stress. Use more infill on functional mechanical parts and objects that need to be durable.

Layer Height The number of layers in a print, or the object’s resolution, is determined by the layer height setting and is measured in microns (one millionth of a meter). High-res objects use many very thin layers to create a smooth object. Low-res objects are made of fewer, thicker layers and feel rough to the touch. Items intended for display purposes are typically printed in high resolution, while prototypes and everyday objects can usually be printed at lower resolutions and at faster speeds. High-resolution objects take longer to produce than low resolution ones. Use a bigger layer height for prototyping and rapid production. Use a smaller layer height for display objects and more-accurate tolerances

Wall Thickness Minimum wall thickness is defined as the minimum thickness that your model should have at any one given point. A thinner thickness results in a fragile the 3D object A thicker the wall thickness results in a sturdier 3D object.

The End There are many more 3D terms and not enough time to cover them all. We will learn them together as we progress. I hope you learned something new! RCJoseB