RepRapOneDarwin
Contents
How to build RepRap 1.0 "Darwin"
These pages are under construction.
This page, and those to which it links, are a comprehensive guide to making the first release of the RepRap machine: RepRap 1.0 "Darwin". However since Darwin is not yet complete, neither are these instructions :)
Joining the RepRap Research Community
We have set up a not-for-profit RepRap Research Foundation (RRRF) which anyone can join for free. It has a single purpose: "To promote research in self-replicating manufacturing systems and to distribute the results of that research freely to everybody using open-source licensing." To that end it supplies kits for slightly-hard-to-make parts of RepRap at cost to members. See the link for details.
Darwin Release Todo
We're close to being ready, but not quite there. Here is a page with things that are not quite done. Hopefully this will help us get everything organized and ready to rock.
Overview
RepRap 1.0 "Darwin" is a rapid prototyping machine that is capable of making the majority of its own component parts. Instructions and all necessary data are available completely free under the GNU General Public Licence from this website to everyone.
As RepRap 1.0 "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 at cost, as well as using it to make whatever 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 new layers 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
- Line and space: 0.5mm and about 0.2mm
- Feature size: about 2mm
- Positioning accuracy: 0.1 mm
- Layer thickness: adjustable, but nominally 0.5mm
- Computer interface: RS232 (or USB -> RS232) at 19200 baud
- Material handling: Two fixed material deposition extruders, user exchangeable
- Power supply needed: 8A max, 3A continuous at 12V DC
- Driving computer and operating system needed: Microsoft Windows, Linux, Unix, or Mac.
Bill of Materials (BoM)
Click here for automatically generated BoMs.
Alternatively, the current parts lists, as well as links to suppliers where available are listed below. If you have any questions on parts, please ask on the forums.
| Module | Extra Output Formats |
| Master Bill of Materials | HTML - PDF - Open Office - Excel - Google Spreadsheet |
| Cartesian Robot | HTML - CSV - Text - PDF - Open Office - Excel - RSS - ATOM |
| ThermoPlast Extruder | HTML - CSV - Text - PDF - Open Office - Excel - RSS - ATOM |
| Universal Controller v1.2 | HTML - CSV - Text - PDF - Open Office - Excel - RSS - ATOM |
| PowerComms v1.2 | HTML - CSV - Text - PDF - Open Office - Excel - RSS - ATOM |
| Opto Endstop v1.0 | HTML - CSV - Text - PDF - Open Office - Excel - RSS - ATOM |
| Stepper Tester v1.0 | HTML - CSV - Text - PDF - Open Office - Excel - RSS - ATOM |
| Darwin Miscellaneous | HTML - CSV - Text - PDF - Open Office - Excel - RSS - ATOM |
The STL files for all the rapid-prototyped parts of RepRap can be downloaded from Sourceforge here.
At the moment the STL files are not all generated from AoI, and this means that not all of them will load properly into the RepRap software. We are working to correct this, but meanwhile here's a workround (thanks to Andy Sterne).
Procedure for generating corrected .stl files from Solidworks:
- Open the file in wordpad or notepad
- Save it with the extension .csv instead of .stl
- Use Cntrl+H to replace all spaces with a comma and a space
- Save the file and exit
- Browse to the file and double click on it to open it in Excel
- Use Cntrl+A to select the entire worksheet
- Right click and select format cells
- Select the Number tab and highlight the category Number
- Change the Decimal places to 12
- Click ok
- Use Cntrl+C to copy the entire worksheet
- Open wordpad or notepad and use Cntrl+P to paste the entire worksheet into the file
- Save the file with a slightly different name and with the extension of .stl
- Open RepRap.jar (or run the program from Eclipse) and load the part file to verify
What order to do things
The first thing to do is to get the software you will need working. It will run without a RepRap machine attached, and - as you start to build hardware - you can connect it up in a partly-finished state to your computer for testing.
After installing the software, you should start to build the six circuit boards for the electronics of the RepRap machine. The first (and simplest) controls the communications, the next three control the X, Y, and Z axes of the machine, and the final two control the machine's write heads. Note that it says "start to build". With the exception of the communications board, the boards are all based on the PIC 16F628 microcontroller, and each board will work with just that chip and its power supply. You build the boards with just those components on plus an indicator LED each. Then you connect them all up (first individually, then together) via the communications board to your computer and check that everything is talking to everything else.
Then you put the driver electronics on each of the last five boards to connect to the motors, heaters, and sensors of the RepRap machine. Once more you can test without the rest of the machine - just plug in the stepper motors, for example, and the software will cause them to rotate on your workbench.
Finally, you build the hardware of the write heads and the Cartesian robot that carries them. The order here is not so important, but probably a good way to progress is to make one write head, then make the robot, then get those working together. Finally you add the last head, and your RepRap machine is complete.
Software
Currently, most stuff is from-source only. We are in the process of getting binaries ready. Some may already be out!
Requirements
- A fairly modern computer
- Decent graphics card (ATI / NVidia) 64MB+
- Recommended at least 512MB of RAM
- Serial port or USB <-> Serial converter
- Ubuntu/Linux preferred, but OSX and Windows also work.
Files to Download
We offer a few different packages on SourceForge. At some point or another, you will probably need all of them. We keep them as separate packages to make maintenance easier. There are packages for the host software, firmware, electronics, and mechanics.
More info about the files on SourceForge.
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 Linux or Unix (most reliable)
- Downloading and installing the RepRap software under Microsoft Windows (under construction)
- Downloading and installing the RepRap software on a Mac (being written)
Electronics
The electronics are the brains of the system. We have developed 2 electronics systems: a first and second generation. The first generation is relatively stable and working, and the 2nd generation is experimental and may be subject to change.
Continue reading about the electronics systems or skip to the generation 1 electronics.
Toolheads
Thermoplast Extruder v1.0
This is the hot center of the machine. It can melt a variety of plastics and extrude them out in a thin stream to form a line. Put enough of these lines side-by-side end-to-end and you get a layer in a shape. Stack those up and you have an object. That's additive manufacturing, and it's the whole principle of RepRap.
Paste Extruder v0.1
The paste extruder will be used to extrude a variety of paste-type materials that can be used as structural support and for other purposes. It is currently under development so its design will change. But it works and it can be built now.
Cartesian robot
Cartesian Assembly (Mechanical)
Click on the heading, folks. It's all in there.
Cartesian Assembly (Electrical)
The cartesian robot is mechanical element of Darwin. The assembly moves the tool heads around in the X & Y planes to print each layer shape and drops the Z axis down one increment when each layer is completed. Follow the links above to find out what parts you need, and how to put them all together...
Printing in 3D
Tweaking
You now need to tweak the software so that your hardware can print coherently. The parameters can be accessed by running the RepRap software and clicking on File -> Preferences. It is probably best to experiment with a simple STL.
Documentation for these parameters can be found here.
First Printing - Cheers!
If you've successfully assembled and tweaked everything and are ready to take the plunge, load up this file into the RepRap build area and start the job. After X minutes a few small cylinders suitable for drinking should appear. Gather your friends and fill them with your age-appropriate celebratory substance of choice. Say a cheesy line, and drink. This will demonstrate some excellent properties of your new machine: that the axes work, your extruder works, and the plastic seal is watertight. Welcome to The Future.
Feeding The Extruder
For experiments and calibration, you can just poke a metre or so of filament into the extruder. To make substantial components you'll either have to keep joining more bits on, or use a spool mounted so that it can feed the extruder without kinks. One approach is detailed here
Spare Parts and Replication
Now that you have a working machine that is well supplied with raw material, make one each of all the component parts of your machine and put them in a cardboard box on a shelf in a cool dry place. In the future if anything breaks, you'll then have the right spare part. If that happens, replace the part, make another, and put that back in the box. In addition to making copies of itself, RepRap can, of course, repair itself...
Also, don't forget to make two machines for friends or colleagues. It's by no means required, but it is definitely in the spirit of the project. The project is free (as in speech), but unfortunately real stuff costs money, so the common etiquette is to pay for raw materials / shipping / construction time.
Supply
In fact, since its in the group's best interest, we will probably be doing group buys in the future through the RepRap Research Foundation (RRRF). The more people we get, the better prices we can negotiate. Additionally, since it is often easiest to buy as an individual, we will also be listing suppliers where you can get parts. This is a good thing since with this shared knowledge, we'll be able to compare prices as an internet community and if someone finds a supplier with the lowest cost with a compatible part, then we can highlight that source and everyone will benefit from the savings. Economics dictates that the larger this project gets, the cheaper its components will be.
-- Main.ZachSmith - 01 Feb 2007
