This is a bellow to protect the Y axis ways of my CNC mill ( http://www.thingiverse.com/thing:8527 )

The base material is office paper (80 g), coated with liquid rubber later in the process. The rubber coating not only improves the bellows stability, but also gives the bellow some basic protection for oil and/or cooling liquid.

Download the PDF with the template and print it on DIN A4 paper (if you're using legal size, resize the template, preseving the aspect ratio).

Score the horizontal and diagonal lines with the back of a knive or such (I used a glass cutter, which worked well). Be careful not to give too much pressure on the tool. You don't want to cut the paper, just score!

Then fold a bellow :)

See the YouTube film at http://www.youtube.com/watch?v=v6VLRqwGDeI to get an idea of what I'm talking about.

Then use liquid rubber to coat the bellow on the outside. It's ok to un-fold the bellow for the first coating, but you want to re-fold the bellow before the rubber sets. Otherwise it might be difficult to get the paper back in the right shape.

Let the whole thing dry.

To attach the bellow to your mill, 3d printer or whatever, glue an U-shaped end-piece on each end of the bellow. I used .5mm sheet aluminum for this, which is easy to cut with a normal scissor. But cardboard or plywood might be ok also.