I have been meaning to do this for quite some time, and just the other day I finally used the ShopBot Alpha
at TechShop San Jose to plot a vectorized San Jose Sharks logo that I made using Illustrator.
The process is fairly simple
here's how I did it....

I used:

Adobe Illustrator
VCarve Pro
ShopBot Alpha
Sharpies
Blue painters tape
and some homemade paper =)

Step 1: Vectors, Vectors, VECTORS!!!

First off, you need a vector file in order to plot. Using Illustrator (or CorelDRAW, Inkscape, VCarve itself, AutoCAD.... etc. pick your favorite CAD/vector art program) make a file that you want to plot.

Step 2: CAM - Make Your ShopBot Files

Once you have a vector file that you want to plot open up VCarve to setup to the file for the ShopBot.
In VCarve there are many options for setting up tool paths, and depending on the type of art work you
are trying to produce you will need to choose an appropriate tool path operation.

There is much experimenting to be had with this, but this is what I did for my first attempt.

For fills I used a pocket tool path and for outlines I used a profile tool path.

Fills: experiment with the tool diameter to get tighter or looser fills depending on what effect you are going for.
(fills could also be manually controlled by creating specified fill paths in your vector program of choice)
In the Edit Tool options: you will also want to change your feed rate. For mine I used 4 in./sec.
Your are not cutting anything so you can set it to go pretty fast.
(Hint: If you try using a paintbrush or some drawing instrument that can run out of pigment, set a slower speed so you can pause the machine in time to add more pigment)

Outlines: again try experimenting. For outlines the key option you want to have selected is Machine Vectors set that to ON. You probably do not want an offest, rather you want the ShopBot to Plot directly on the center of the line that you drew.

Lastly you want to make sure your cut depth is very very small to ensure that you don't break your drawing instrument.
For mine I set it to .001 in.

If you are using multiple colors like I did make sure to save separate .sbp files, one for each color.

Step 3: Setting Up the ShopBot

Once you have your files ready its time to go to the ShopBot.

Since we are not actually cutting any material work holding becomes a lot easier. I simply used
blue painters tape to stick my paper to the ShopBot bed.

Attaching your drawing instrument.... this could potentially be tricky.
I used a standard Sharpie pen, which has a shaft diameter that is slightly smaller than 1/2 in.
The largest collet available at TechShop San Jose is 1/2 in., so with a little help from blue painters
tape you can get it to fit nice and snugly into the collet.

Setting zeros is pretty straight forward. X and Y I just eyeballed. For the z-axis, using the zeroing plate
is not an option since the drawing tool is not metal. I manually zeroed Z by using a fixed distance (I used .01)
and gradually stepping down until the Sharpie touches off on the paper.

Step 4: Plotting Time!

Simply run your .sbp files and plot away.

In the future I plan to design and make a chuck
so attaching other drawing tools will be hassle free.
More posts to come... happy plotting =D