RepRap Options

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Revision as of 17:43, 12 June 2011 by Bubbapizza (talk | contribs) (Massive rework of build instructions)
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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

STL 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

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.

A Note about STL files

STL files are an open file standard and are widely used in Computer Aided Manufacturing and rapid prototyping. The STL format is good for printing out parts because it only describe the part's surface geometry. However, STL files are terrible for doing Computer Aided Design. They can be imported into CAD applications but are difficult to change.

True CAD applications use CSG type files because they are easy to change and mainipulate. In general, parts should not be designed and saved as STL files. When designing parts, files should be saved as in a CSG-friendly format such as:

  1. the CAD application's native format or
  2. a STEP file

STEP files are basically the gold standard for translating between different CAD applications. People that do CAD for a living use STEP files.

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.


Electronics

From what I can tell, the reprap electronics consist of an arduino board with a SD card reader and a controller board for the x,y,z axis motors and the plastic extruder. It looks like the arduino has a custom firmware uploaded to it that does the Gcode interpreting.

I'm guessing the schematics for the motor controller board and the source code for the g-code interpreter are in the subversion repository somewhere.

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.

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

The RepRap Mendel now comes in 3 major variants. Each version is ready for you to build.

Please note that the Huxley is still somewhat experimental. Huxley is not yet fully documented.

Mendel

Mendel.jpg
The original Mendel design

Select Mendel

Prusa

Assembled-prusa-mendel.jpg
The faster to print, cheaper to build Mendel Variant

Select Prusa

Huxley

Huxley.jpg
The travel-sized Mendel Variant

Select Huxley



More Mendel design improvements are also available on the Mendel Development page.


Legacy

Darwin

All 3 axes fdmd sml.jpg
The first RepRap design

Select Darwin