Build a RepRap

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Revision as of 13:34, 20 June 2011 by Bubbapizza (talk | contribs) (A Note about STL files)
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The process of building a fully functional reprap can be broken down into three major areas:

  1. The software toolchain that generates instructions for the reprap
  2. The electronics that read the instructions and handle the movement of the reprap
  3. The mechanical body that does the actual printing

Software Toolchain

Part Files

To print out reprap parts, you first start out with 3D part files. In general, 3D part files fall in one of two file categories. Wireframe files or Constructive Solid Geometry (a.k.a. CSG) files. Reprap parts are stored in the reprap subversion repository as STL files. STL files fall into the wireframe category. To get a copy of all the necessary STL files for making a reprap, run the following commands in ubuntu:

sudo apt-get install subversion
svn co https://reprap.svn.sourceforge.net/svnroot/reprap/trunk/mendel/mechanics/solid-models/cartesian-robot-m4/printed-parts/

This will create a directory full of STL files that you can then give to your neighbor that already has a reprap and they can print out the parts for you.

Applications

To make or parts, you will need to convert STL files to Gcodes. To do this you have to use some software which I haven't figured out yet.

Also in here should be a list of applications for viewing STL files such as Blender and Google Sketchup. There should also be some notes in here about open source vs. proprietary CAD applications. From what I can tell, there's really only two major open source 3D CAD applications: openSCAD and Freecad. Freecad seems to be the only open source CAD app that can import and export STEP files. It is pretty buggy on the import though. When I tried to import the STEP file for Mendel, it totally bombed.

Aha, I have found out the reprap team has designed all their parts using Art of Illusion

Electronics

RepRap electronics consist of a board similar to an Arduino, but additionally equipped with drivers for stepper motors, heater(s) and temperature reader(s). To make this work together, the controller is programmed with one of the RepRap firmwares (FiveD, Teacup, Sprinter). The movements required to build a part are sent via USB to this board by a PC sorftware called RepRap Host. The communications language between Host and firmware is G-code, a somewhat extended dialect of the G-code used for milling machines.

Bill Of Materials

To buy all this stuff, there should be a spreadsheet with the bill of materials and pricing from different suppliers. I think I saw the BOM is somewhere else in the wiki.

Assembly and Testing

Some info on how to put the electronics together and how to test that everything is working ok goes here.

Mechanical Body

This is the part of the reprap most people are probably eager to build.

There are around 40 parts in the Mendel that you have to print out from an existing reprap. If you don't have access to another reprap (which is probably 99.9% of the people reading this), you'll have to make those parts by hand using wood or steel I'm guessing. If you don't have a wood workshop or CNC machine, I guess your best bet is to find a local machinist or carpenter that can make them for you.

Unfortunately, most carpenters or machinists will need blueprints to make the parts. At the moment, there are no ready-made blueprints you can download and print out. A print (I've been told they just call them 'prints' in the trade) usually shows the front. top, right, and sometimes isometric views of the part with measurements on it. This is where the reprap project could seriously use some help.

However, to make prints, you'd pretty much have to redraw all the STL files in a 2D or 3D CAD app. If a 3D part is designed in freecad, it can do the projections (prints) for you but you can't put any dimensions on the parts. According to the freecad team, you'd have to export the prints as dxf files, and import them to QCad to add dimensions.

Bill of Materials

Other than the printable portions of the reprap, again, you'll need a spreadsheet listing parts to buy, suppliers, estimated cost, etc.

Building the Body

To build the body, take a look at the STEP file in the source code, look at videos and I think there's stuff elsewhere in this wiki.

RepRap Models

For the full evolution of RepRap models, check out RepRap Family Tree.

Current

The RepRap Mendel now comes in 3 major variants:

  1. Mendel - The original reprap design
    Mendel
  2. Prusa - The faster to print, cheaper to build Mendel variant
    Prusa
  3. Huxley - the somewhat experimental, not-yet fully documented, travel-sized Mendel variant
    Huxley

Legacy

These models are not being developed any more:

  1. Darwin - The first reprap design
    Darwin

Improvements

Mendel design improvements are available on the Mendel Development page.