3D PRINTING BASICS


Table of Contents:

1. What is 3D Printing?
2. Why use 3D Printing?
3. Applications of 3D Printing
4. 3D Printing Software
5. 3D Printing Guide

 

What is 3D Printing?

3D Printing is an additive manufacturing process to create a physical object from a 3D design.

For this purpose, a digital 3D model of the desired object is required. The digital model is usually saved in STL format which is then sent to a 3D printer. The object is printed by adding material layer by layer.

 

 

 

 

Why use 3D Printing?

Some of the benefits of 3D Printing are :

Cost Efficient

3D Printing reduces the cost of prototyping as 3D printing does not involve any tools as compared to traditional prototyping techniques. Therefore, 3D printing eliminates the stages of tool production and the associated costs and the prototypes can be manufactured at optimum cost.

Fast

Once a CAD file is finalized, the design is sent to the printer which prints the design with little or no involvement from anyone. On the contrary, traditional prototyping requires tools and machining which may take up to weeks. Also, almost every design is modified a number of times and with 3D printing, generating a prototype for every design is easy and fast.

Customization

With 3D printing, it is easy to customize the products according to your customer’s needs and requirements.

Applications of 3D Printing

Prototyping

The main application of 3D printing is Prototyping. 3D printing speeds up the initial stages of product development by producing prototypes quickly and efficiently at an optimum cost, thus saving time and money. Traditional prototyping techniques are costly and slow because of the use of different tools depending on the type of prototype. Developing a prototype is a necessity of many industries like automotive, aerospace etc.

Educational Purposes

3D printing is becoming very popular in the field of research and education. It provides 3 dimensional visual aids which help students to understand a concept much better as compared to 2 dimensional figures printed in books. Students can enhance their learning capabilities by doing practical work with 3D printing, especially in engineering and architecture, media studies.

Architects

With 3D printing, architects can easily make architectural models of their designs meeting the requirements of the customers.

Doctors and Dentists

3D printing is also very useful in medical field. Doctors and dentists can scan a body part of a patient and develop it into physical object for further investigations or for prosthetic.

Art / Sculpture

Develop your designs into real models.

Fashion

Companies can make customized products for their customers at much affordable prices.

3D Printing Software

Like an office printer, 3D printer also requires some software/tools to convert your designs (3D models) into machine readable instructions. Two types of tools are required.

1.  CAD Tools
2.  CAM Tools

CAD Tools

CAD (Computer Aided Design) tools are used to make 3D models of your design.

Most 3D printers require 3D models in STL format. Make sure that CAD tool you are using saves the object in STL format otherwise you need to convert your 3D model into STL format.

There are many CAD tools that are free. Some of them are:

1.  Autodesk 123D Design
2.  Blender
3.  BRL-CAD
4.  FreeCAD
5.  3DTin
6.  OpenSCAD
7.  K-3D
8.  Sketchup
9.  Tinkercad

Some of the above sites also offer premium features, please visit the respective sites to know more. There are also many commercial CAD software available.

If you have no experience with 3D modeling, we would advice you to check Autodesk 123D Design and Blender first. Modeling with these two software is easy and you can easily export your models to STL format.

You can also download 3D models from online repositories like Thingiverse, GrabCAD or Yeggi.

CAM Tools

CAM (Computer Aided Manufacturing) tools are used to translate CAD files to machine readable format (G-code).

Two categories fall under CAM tools.

1) Slicing Software

Slicing software generates G-code (machine readable format) from STL files (CAD files). For this, you can use one of the following applications:

1.  Cura
2.  Slic3r
3.  Repetier 
4.  MatterControl
5.  Simplify3D

2) Print/Host Software

After generating G-code, you need to send the file to the printer to start printing. To do this, connect the printer to your computer using USB connection and use one of the following applications:

1.  Cura
2.  Pronterface
3.  Repetier
4.  ReplicatorG
5.  MatterControl

 3D Printing Guide

This page gives an overview of the steps involved in 3D printing. Also, the terminologies used in slicing software are explained so that you can easily and quickly start with your first print.

Step 1 : 3D Modeling

Step 2 : Slicing and Printing

 

Save ‘.gcode’ file on SD memory card. Insert the card in the card slot provided on your printer. Select the required file to start printing.

As complex designs may take hours to print, it is always better to print through SD card instead of connecting your computer to printer through USB cable.

TIPS

a) For first few layers:

  • Check that the printed material is sticking to the bed. If not, clean the base and place Kapton tape on it. Try to increase either bed or extruder temperature.
  • Filament is feeding correctly.
  • If the printer makes weird unnecessary movements, try slicing again using different settings.
  • Make sure that the dimensions of your design are within the working area of the printer.

b) After printing is done:

  • Wait for the bed to cool down before removing the object. Removing the object too soon may warp it.
  • Finished product may have some brims on the bottom which can be removed using a knife or file.
  • If there are blobs or holes at the surface, check if the extruder is working correctly and adjust the extruder temperature.

 Terminologies for slicing your 3D model

  1. Layer Height (mm) – This refers to the height of each layer of plastic to make the desired part. Higher values print fast, lower values focus on better quality. 0.05mm – 0.25mm values are acceptable.
    Start with 0.1mm and then adjust according to your need.
  2. Shell Thickness (mm) – This is the minimum wall thickness. This value should be a multiple of nozzle size. If your printer uses nozzle of 0.4mm, then keep shell thickness 0.8mm or 1.2mm.
    Note – 0.8mm should work fine.
  3. Enable Retraction – Enabling this will retract the filament while the nozzle moves over a non-printing area. Do keep this enabled.
  4. Bottom/Top Thickness (mm) – This refers to the thickness of bottom and top layers. Keep this value multiple of layer thickness and close to shell thickness.
    Note – If layer thickness is 0.1mm and shell thickness is 0.8mm then bottom/top thickness should work fine.
  5. Fill Density (%) – This value defines how much filled the inside part of your print will be. Usually, 15% or 20% works fine.
  6. Print Speed (mm/s) – This is the speed at which the printing is done. Start with a value of 50 and then adjust accordingly.
  7. Support – This option provides support to the designs that have hanging or unsupported parts. Try different options in the software to meet your requirements. These supports can be easily removed after printing is completed.
  8. Filament Diameter (mm) – Just type the diameter of your filament.