This is Day 11 of my collection of printable equations. To see the whole collection, go to:http://www.thingiverse.com/thing:227210
Based on plastic's request in the comments, (http://www.thingiverse.com/thing:231587/#comments), for today's equation, I'm doing y = sin(cos(x/7)+sin(x))*x. I've included the Openscad file in case someone wants to modify the text or stand.
As always, I'm going to continue to post one equation per day until get bored or people lose interest. If there's a particular equation you'd like to see, leave a comment and I'll give it a shot.