RepRapOneDarwin2

RepRap 1.0 "Darwin"

Overview

RepRap 1.0 "Darwin" is a rapid prototyping machine that is capable of making the majority of its own component parts. Instructions are available completely free under the GNU General Public Licence from this website to everyone.

As Darwin can copy itself, once you have one you can make others for your friends; or if they have one you can ask them to make one for you. Of course, you can also make as many as you want for yourself; the more you have, the faster you will be able to make other items. RepRap etiquette asks that you use your machine to make the parts for at least two more Darwins for other people, as well as using it to make whatever else you or anyone else on the internet can think up!

Darwin consists of a frame made from rods and printed parts. A flat build platform moves vertically in that frame, driven on screw threads by a stepper motor. At the top of the frame there are two write heads that move horizontally (driven by toothed belts and two more steppers) extruding a thin stream of molten plastic to form a new layer on the build base. The machine prints layer by layer to form a solid object. The build base then moves one increment down, the second layer is extruded, and so on. There are two heads to allow a filler material to be laid down as well as the plastic. This filler is used to support overhanging parts of the objects being built, and is removed when the process is finished.

Specification

The RepRap 1.0 "Darwin" machine has the following characteristics:

• Working volume: adjustable, but nominally a 300 mm cube
• Working materials: Polycaprolactone and a filler/support
• Configuration: 3-axis Cartesian drive using stepper motors
• Computer interface: RS232 (or USB -> RS232) at 19200 baud
• Two fixed material deposition heads, user exchangeable
• Power supply needed: 8A at 12V DC
• Driving computer and operating system needed: Microsoft Windows, Linux, Unix, or Mac.

Software

These instructions assume that you will be working with the source code of the RepRap software. A little after the first release we will also be putting out binaries for people who do not wish to get into the details of the code.

Installation

Note that all the electronic information needed to build a RepRap machine (that is, the circuit diagrams and mechanical designs, as well as the software for your main computer and the firmware for the RepRap machine's microcontrollers) is available from the RepRap Subversion repository at Sourceforge. In the sections below you will be instructed on how to download all this; not just the software for your main computer.

Follow the link that is appropriate to your computer platform:

• Downloading and installing the RepRap software under Microsoft Windows
• Downloading and installing the RepRap software under Linux or Unix
• Downloading and installing the RepRap software on a Mac

Modeling Software

We have settled on using Art of Illusion (AOI) as our standard modeling software. However, the printer control software takes a standard .stl file to create the slices to make the object, so you can actually use whatever modeling program you want. However, if you intend to modify the files for the objects that make up the printer, you will need to use AOI to edit them.

Electronics

The five circuit boards are connected in a token ring, with the communications controller connecting this ring to the computer.

File:RepRapOneDarwin2-diagram.jpg

Power + Communications Card

The Power / Comms card is the link between the computer and the RepRap printer. It uses RS232 to communicate over a serial port. If you do not have access to a serial port on your computer, there are widely available USB -> RS232 converters available. It also regulates the input power to 12v and provides power connectors for the other boards to connect to.

Signals are passed round the ring until they arrive at the device to which they are addressed, which then acts upon them. There is an extra single-wire synchronisation link from the X axis controller to the other two axes. This allows all the steppers to move together in any straight line without their needing to transmit data round the ring for each step.

See here for more details on the Power/Comms card.

There are 2 ways to get a Power/Comms card:

Build It

Buy It

• if you are would like to parts, please contact the RepRap team to be added here.

Toolheads

Future Tools

-- Main.ZachSmith - 01 Feb 2007