Introduction: Introduction to 3D Printing

3D printing is a quickly expanding field, with the popularity and uses for 3D printers growing every day.  In this guide, I will attempt to give an introduction to the wide range of technologies in 3D printers, a comparison of the most common 3D printers on the market, an overview of materials that can be used to print, online services and communities that offer 3D models or 3D printing services, and an intro to designing and printing your first model.

3D printing can be used to prototype, create replacement parts, and is even versatile enough to print prostheses and medical implants.  It will have a growing impact on our world, as more and more people gain access to these amazing machines.

Step 1: Technologies

While all 3D printers create objects using additive methods (the opposite of a CNC machine), different approaches exist to actually physically depositing the material.  The most common methods are:

-Fused Deposition Modeling-  A very common method in which the part is printed by extruding molten stings of material that melt together to create the part.  This is usually the cheapest method, but quality can suffer, and materials are limited.  Examples include:  Maker Bot, RepRap, Objet, Cube, Solidoodle, Dimension and many others. 

-Selective Laser Sintering -More common in industrial style prototyping settings,  a laser melts together powdered plastic, ceramic, or other material, then spreads more powder on top, repeating the process to build the part layer by layer.  The main advantage of this is the wide variety of materials that can be printed.  Examples include: SinterStation

-Powder Bed and Binder- Similar to Laser Sintering, an inkjet head distributes binder to the correct location on a bed of powder.  The most notable advantage is the ability to print in many colors.  Examples include: ZCorp

-Stereolithography- Here, an ultraviolet laser hardens resin in a vat layer by layer until the part is built.  It can quickly create high definition parts that can be machined.  However, the resin is fairly expensive compared to other 3D printing materials.  Examples Include: Instructables User RobHopeles's Stereolithography Printer

Step 2: 3D Printers

While there are countless 3D Printers in operation, several models and brands are the most common and well known.

Price: Cost of base model in USD
Technology: FDM, SLS, PBB, or STG
Maximum Object Dimension (MOD):  The size of the largest object the printer could print.

General Description (Alphabetical Order):

Cube-  Price: $1,299  Technology: FDM  MOD: 5.5" by 5.5" by 5.5"
The Cube Printer's main selling point is it's ease of use and style.  Compared to other printers like the RepRap, it is very aesthetically pleasing.  WiFi connectivity frees you of the need for wires.

Dimension Elite- Price: $29,900  Technology: FDM  MOD: 8"by8"by12"
The Dimension Elite is one of their top of the line models.  Intended for industrial or buisness prototyping, the price is high, but the quality and speed of the print are good.

MakerBot Replicator-
The MakerBot was fairly early on the scene of open source 3D printing.  With it's distinct laser cut wood frame, and open source hardware, it is one of the most popular 3D printers among makers.  An optional Dual Extrusion head (for $250) lets you print in two colors.

Objet Connex 500-  Price: Around $250,000  Technology: FDM  MOD: 500 by 400 by 200 mm
A very top quality printer, it is very vesatile and can produce many types of materials.  While it uses FDM, it can print 14 materials at once, in materials including rubber, engineering plastic, and transparent plastic.  And it can print all of that at a resolution of 16 microns.  This is the printer that Instructables uses.

3D Systems/ZCorp-  Price: Varies  Technology: Mainly SLS, PBB and SLA  MOD: Varies
3D Systems is a popular 3D printer manufacturer that specializes in SLS and SLA. ZCorp is owned by 3D systems and developes PBB printers. With uses including mainly centered on businesses, engineers, and industries, depending on  these printers might fit your need.

PrintrBot-  Price: $399-949  Technology: FDM  MOD: 4 by 4 by 4" to 8 by 8 by 8"
Anothe Printr aimed at the maker market, this FDM machine was loosely based on the Rep-Rap, but has now advanced to some more sophisticated and good-looking printers.  The price and siz are a large selling point for this printer.

RepRap-  Price: Varies Technology: FDM MOD: Varies
RepRap isn't a company, but a project with plans and istructions for making your own 3d printers.  Quality and price varies by design, and the goalof the project is to make printers that can print more printers.

Solidoodle-  Price: $499 Technology: FDM MOD: 6" x 6" x 6"
The Solidoodle is proably one of the best price 3d printer out there.  At around 500 dollars depending on the features, the Solidoodle is less than half the price of the Maker bot, but can print at a comparable resolution and speed.

UP!- Price: $1,699  Technology: FDM  MOD: 5-1/2"(w) x 5-1/2"(d) x 5-1/4"(h)
The Up pirnter has a similar design goal as the Cube: to make consumer 3D printers easy to operate.   It has fairly good resolution for its price, and has an appealing design.

Step 3: Materials

Materials vary from technique to technique.  The most common for FDM is spooled ABS style plastic filament. However, many other materials can be printed, including ceramic, metal, rubber, clear plastic, glass and others.  The materials available are dependent on the method of printing.

Step 4: Online Communities and Services

There are a wide variety of online resources for finding 3D files.  As always use discretion when downloading anything from the Internet.  Such places include:




Google Warehouse

In addition to these databases, companies will actually print your models for you.  This offers the advantage of having access to a wide range of 3D printers and different materials.  Many of these companies also provide places to sell and buy 3D files that you can print out.




and others...

Step 5: Design and Print

When it comes to modeling 3D files for a printer, the most commonly accepted format is an STL file, which is essentially a mesh made of triangles.  You can use your preferred CADD software to create the model.
Free programs include:

Personally, I like Sketchup.  However, the free version does not natively export STL's.  After trying many other programs to convert from Sketchup files to STL's, I settled upon a plugin for Sketchup that is described (along with other options) on the MakerBot Website.

Then you can convert it and make any changes in another program more compatible with STL files.
These programs include:

All of your models need to be what is called "water-tight."  A model being watertight (also called a manifold model) means that there are no holes in the mesh that could cause issues while printing.  A good guide to this can be found on the Ponoko website.

NetFabb is a great tool for fixing  issues yourself.  Even the free version includes a tool that lets you automatically check water-tightness and fix it.

Once you have the design, the object is sent to the printer.  Most printers have software that lets you convert the STL to the layers that the printer will print in and commands for the printer.  Depending on the method of printing, there will likely be some support material (which helps the object print by supporting delicate pieces) that will have to be removed using a vacuum, brush, or water, depending on what type of material it is.

Step 6: Examples

A few examples of what you can do with a 3d printer.
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