CNC Gantry Using Drawer Slides

I have wanted to build a CNC machine for years.  I've finally gotten around to it but am keeping the cost and complexity as low as possible.  While using drawer slides is not the best method I wanted to play around with them and see how they would work.  

I've built the first part of this project using plywood from a local hardware store and the drawer slides from Lowes.  The drawer slides that I used were 18".  I will probably move up to 28" slides; they are around $20 a pair and will give a longer run.

This is just the first video of this project.

Thanks for taking a look.