And now to delve into the last several days worth of work.

Since I am going to jump in telling you about a specific part of a big project, I will first give you a short description to bring you up to speed.

I am building a 3D printer- a printer that, as one would guess, prints in three dimensions. More information about the project can be found here. Over the last several days I have been working on the electronics- the control system for the printer. The printer is an open source project and much of the groundwork has been laid which gives me an opportunity to be out of my comfort zone (electronics! eeek!) and still have the confidence that I will see the project through. The support from the community is great and I am learning alot!

So.... what I've been doing. I'm using the Arduino Mega board which is another open source project. The arduino is a beefy microcontroller with a bunch of input and output pins setup to function according to a C program that is loaded onto the board as firmware. In a nutshell, the computer tells arduino to move the print head to a given location. The arduino takes that information and tells the motors what to do and how to get there. The arduino can't interact directly with a motor so a stepper motor driver sits between the arduino and the motor. The arduino tells the driver to step or change direction, and the stepper motor driver energizes the motors coils appropriately. The stepper motor drivers that I am using are the Pololu A4983 boards. They run hot and I plan to use a cpu fan to cool them. The reprap page I've been referencing is here.

For a good two days of work I don't have much to show but much of that effort went into learning the required software. I first sat down and tried to decide between fritzing, kicad, and eagle. They've all got their quarks but I eventually found kicad to be the most intuitive and powerful. We will see if I still think the same when I am through.

So what is the software and what am I using it for? Kicad is computer aided design software specific to circuit board design and layout. It allows you to layout a schematic and then design a pcb tailored to the schmatic. I am making a shell for the arduino- a circuit board that fits over the top of the arduino. The shell will house all the components required included the pololu drivers. There are already several people doing very similar things but I want to do it myself for several reasons. First and formost was to learn the software and workflow but also because I will be making the board on my cnc mill and so my requirements are slightly different than the other reprappers. Getting the workflow down- from schematic to a physical board will prove very valuable in the future, whenever I need to make a circuit board

Part of the physical layout:

Schematic:

Pcb:

Several hours later, a whole lot of text and a picture or two.

This may take some practice, but I will get better!