3D Printing basics if you consider it for your DIY projects

Cartesian-vs-delta 3D printer

Forewords

The purpose of this article is to introduce neophytes to 3D printing by giving an overview of the different types of printing and printers, the hardware needed to get started and suggestions for tools and software. It is not a question of listing all the tools and software, as it is not the objective to address in detail all the tools, processes and concepts related to 3D printing. The opinions shared in this article concern me only.

3D printing introduction

3D printing, also known as desktop fabrication or additive manufacturing, is a process whereby an object is created from a 3D-model. Contrary to preconceived ideas, the first 3d printing equipment and materials were developed in the 1980s.

The technology used by most hobbyists is fused deposition modeling (FDM), a concept developed in 1988 by S. Scott Crump which marketed its first FDM machine in 1992.

Additive Manufacturing (AM) is a term to describe set of technologies that create 3D objects by adding layer-upon-layer of material. Almost all Addictive Manufacturing technologies use a computer together with special 3D modeling software. The first thing to start this process is to create a CAD sketch (a model). Then AM device reads data from the CAD file and builds a structure layer by layer from printing a specific material.

There are many types of 3D printing technologies, typically referred to by their acronym:

  • SLA (Stereolithography) is a technology that involves curing resin using an ultraviolet laser. Layer by layer, the print is raised out of a vat of resin until it is a complete object.
  • SLS (Selective Laser Sintering) uses a laser to sinter, or bake, powder into a specific pattern to form a 3D object.
  • DLP (Digital Light Processing) is similar to SLA, but it uses ultraviolet light instead of laser technology to cure the resin.
  • FFF (Fused Filament Fabrication) is the most common type of 3D printing, whereby a hot nozzle extrudes melted plastic into thin layers stacked one on top of another to form an object.
  • Polyjet 3D printing is similar to a standard inkjet printer used to print on paper. UV light cures tiny droplets of photopolymers as they are jetted onto a build surface.

For this article, we will concentrate on FDM. It’s the most common type of 3D printing due to its low cost and general ease of use.

Basically, when you need to print an object you will use a 3D-model saved in STL format and then send it to a 3D printer. The 3D printer then prints the design layer by layer and forms the object.

Types of FDM 3d printers

There are two main types of FDM 3D printer: Cartesian and Delta.

3D Printing basics if you consider it for your DIY projects

On the Cartesian, each element moves in only one axis. These printers are named after the most widely used coordinate system which determines where and how the hotend will move. They will typically have a square print bed which will run along the Y-axis. The X-axis will carry the print head and for the Z-axis (up and down) movement.

Deltas will usually feature a circular print bed. The extruder will be suspended above that by three arms in a triangular configuration (thus the name “Delta”). The hot end can move in any direction quickly. These nifty robots were designed for speed and they also have the advantage of a print bed that does not move which could be advantageous for certain prints.

3D printer parts

A FDM 3D printer is always composed of a structure, a print bed, a hotend, an extruder.

3D Printing basics if you consider it for your DIY projects

 

What do you need to start printing from scratch ??

  1. a 3D printer
  2. a 3D modeling software and/or a 3D model
  3. a slicer software
  4. a spool of material
  5. some tools (optional)

What 3D printer for beginners

I strongly recommend the Wanaho Duplicator i3 (or the Monoprice clone). I tried different entry level printers, and this one has been the most reliable starter kit so far. It works great out og the box, it’s not a DIY kit (you just have 4 screws to assemble the structure..). I upgraded mine with a Micro-Swiss all metal Hotend to be able to print Nylon and exotic filaments and it’s working well for a year now (printing almost every day). A smaller version is the Monoprice Mini Select v2 much cheaper but still reliable and durable (the only downside is the print area: 120 x 120 x 120 mm).

3D modeling apps

Resources to download 3D models

Slicers

Materials for 3D printing

PLA

  • Easiest to print
  • Tough, but a little brittle, once it has cooled down (Not very sturdy)
  • Can deform when exposed to heat
  • Many color options
  • Cheap and available everywhere
  • Good for prototyping, parts that are not under lots of stress

ABS: (Home printers)

  • Strong filament
  • Highly Available with a large variety of colors
  • Requires heated bed and enclosure
  • Can be toxic (rejection of small amount of smelly smoke)
  • Good for mechanical parts that need to be strong

PETG

  • Easy to print and has good layer adhesion
  • Durable
  • Can be sterilised (Good for food and drink containment)
  • Requires very accurate temperature conditions to get right
  • PETG can be weakened with UV light
  • Prone to scratches (more than PLA)

NYLON: (Polyamide)

  • Strong & flexible, durable plastic
  • High durability
  • Widely available in natural color (white), can be now found in black
  • Require all-metal hot-end for most of quality Nylon, as the print temp between 240 and 260)
  • Good for parts that can be under lots of friction such as gears and pulleys.
  • Constantly meant to be kept dry in moisture free containers

Flexible Filament

  • Flexible! I use for anti vibration pads and when I want to have a rubber like feeling.
  • Low abrasion / Low shrinkage
  • Consistent temperature from the extruder required
  • Requires direct drive extruder (Bowden extruders may tangle it)

Exotic

There a lot of exotic types of filaments that can be used depending on the application you want:

  • Wood
  • Brass / metal
  • Carbon fiber

Useful tools for 3D printing

– A set of pliers (to clean the material added for supports, to cut the filament)
– Some painter masking tape ( I use the blue one from M3)
– A needle file set to clean your prints

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