This was harder to print than I thought it would be. In the end I altered the code to produce it to flatten the end of the peg and did a little filing post-print. Here's the original thing - http://www.thingiverse.com/thing:37177/#files. In the end, the printed item looks like this: And you can see it in action here: https://www.youtube.com/watch?v=-000ooC7bTY