Friday, July 29, 2011

"Hains" Prusa Mendel RepRap Update: Final Stages

Build Tasks
  1. build frame
  2. add y axis
  3. build x axis
  4. add x axis w/ z axis
  5. add top print plate
  6. build extruder
  7. make hot end
    1. make heat core
    2. make thermistor
    3. assemble hot end
  8. connect electronics
  9. install software
  10. test reprap
  11. calibrate reprap
  12. PRINT!
The hard parts are all done! The machine is essentially built. Not only that, but even though I haven't officially completed steps 9 and 10, I have skipped ahead a bit so I could figure out what I'm doing. I filmed the moment when I first got the motors to turn, which you can see on YouTube.

I got the netbook computer running. I'm using it right now to write this post. That was a major point of anxiety for me because I wasn't sure I could resurrect it and it's going to be the main interface for this machine until I get the SD card thing working. I'm relearning Linux and learning the new Ubuntu OS for the first time.

With the netbook working (which has a web cam built in) I've started live streaming the build. You can check out my UStream channel to see recordings of live parts of the build, and even maybe catch me live while I finish the build and start printing. I'm broadcasting all of the rest of the build and will keep it going while I print for a little while.

The software has also been sorted. Up until a few days ago I was still more or less in the dark about the software process, and frankly, it was the part I was most worried about. I hadn't seen much in the way of tutorial or video about the software, not even so much as someone to outline the process from electronic 3D model to printed plastic.

Here's what I wish I had known from the start, so I could be more confident about completing this project.

From Electronic File to Plastic: A Software Overview

Before you make your first print you need to first load the firmware onto the RepRap's motherboard. The application for that is Arduino IDE. It can be obtained through the Arduino web site.

There are three steps to making a plastic print on a RepRap.
  1. Create a 3D model. Produce an .stl file.
  2. Skein the .stl file. Produce a .gcode file.
  3. Load the .gcode file into the print host application and print.
Create a 3D Model

I recommend Google Sketchup. There are a series of helpful tutorials by Google that will help you get started. You'll need a plugin for Sketchup to export an .stl file.

Skein the .stl File

The model needs to be sliced into layers, and for each layer a tool path, the plot the extrusion head will follow, needs to be generated. This is called the skein. Skienforge is the program to use for this step. This application is also where you set up all the calibration information for the printer. Skeinforge can be picky about the .stl file, so you might need to run it through an automated repair service at

Load the .gcode File Into Print Host

The application that actually talks to the electronics on the RepRap is called a print host. Use the application called Pronterface. With pronterface (usually not capitalized) you can manually control the printer too. So with pronterface connected you can move the print head around, which helps with configuration and testing. When you're ready to print, load the .gcode file and hit the print button.

All of this software is free. All of it is available for Windows, Mac. Only Google Sketchup is not available on Linux. I will be creating videos and screencasts of each step, as well as a summary overview, to make things easy for you. Stay tuned.


N0M4dIC said...

This is very useful information. The RepRap wiki is a mess and it is almost impossible to understand where to start. The only thing that need better detailing now is tuning the printer.

kwixson said...

Yeah, the tuning tutorial will be forthcoming. It is a bit tricky, but ultimately I'm getting it pretty well dialed in. Thanks for commenting. Subscribe for updates.