The Ultimaker – a short introduction
Affordable 3D printing allows people to locally print almost any designable object. Once widespread, this has strong repercussions across our society (PDF).
The Ultimaker is a new 3D-printer that can print objects out of thermoplastics like ABS and PLA.
Assembling the unit – though requiring some dedication and love – does not require special skills or tools.
The 3D printing process
The Ultimaker has a square frame, with a horizontally moveable printhead and a vertically movable build table, an XYZ movement also known as a 'Cartesian bot'. The print head can move accurately at higher speeds than other 3D printers, making it both faster and print at up to 5-10 times more details than usual.
The heated printhead (the Extruder) will deposit a layer of molten plastic on the build table. Then the build table lowers a fraction of a milimeter along the Z-axis and the printhead will deposit a new layer that fuses with the previous one. The table lowers again for the next layer and so on.
The X, Y and Z movement is performed by three stepper motors, that are controlled by an electronics board.
A fourth stepper motor for the extruder makes sure the right amount of plastic filament is delivered at the nozzle of the printhead at the right time. The Ultimaker board itself is designed to be soldered by anyone, so no tiny SMD parts are used. However, the kit provided in the webshop is pre-assembled and comes pre-loaded with working firmware.
The brains of the Ultimaker is an off-the-shelf Arduino Mega 1280 which clicks to the board.
The Arduino's firmware will accept and execute commands to drive the steppers and print the layers.
The latest stable firmware is available free on www.ultimaker.com
The Ultimaker uses the ReplicatorG that is available for Linux, Mac and Windows. This is free software, both as in freedom and free from price. Download and installation instructions can be found here. If you fire up ReplicatorG it will connect to the Ultimaker. It then offers a dashboard so you can check its functions: move the X,Y,Z axis, test the extruder and set the required temperature.
ReplicatorG can print 3D files that come in the standard .stl format, whether written by yourself or downloaded somewhere. The .stl file of a 3D-object has to be sliced into layers that can be printed by the extruder. ReplicatorG will do that with its function “generate G-code”. The result is a G-code-file that the Arduino firmware can execute to drive the stepper motors; a layer at the time.
It is wise to start with some simple calibrations files as are available on www.thingiverse.com. If you start with the default settings, there is a fair chance your Ultimaker will work straight away and print your first object. However, be prepared to do some tuning as each Ultimaker is unique - for instance for the required flow of its specific nozzle - and also various filaments have their specific characterics, like optimal melting temperature.
ReplicatorG contains a program which allows you to tune your Ultimaker for those specific settings. It is called Skeinforge and comes from the RepRap community.
With Skeinforge you can set and change every parameter of the printing process.
Skeinforge looks a bit intimitating at first, but fortunately there are just a few parameters that really matter: feedrate (speed of the nozzle movement), flowrate (the amount of plastic fed to the nozzle) and layer thickness.
Playing around with these three will get you to a stable result.
Settings for a specific material or object can be stored in a Skeinforge profile and called later when generating G-code for a different object to be made from the same material. ReplicatorG comes preloaded with a number of standard profiles, and you can add your own.
- Introduction to 3D Printing
- Ultimaker 3D-Printing Workflow illustrated in a blog post on Techwall.net
- "Ultimaker FAQ: but what about the quality of prints?" blog post on Dave Durant's Blog