This is a spindle to turn a used CD/DVD into a balloon-powered hovercraft/air cushion puck.

It's the first original CAD for me and my 10-year old boy.

Hoverdisk in action: http://www.flickr.com/photos/splatspace/5231943755/

Print on a Makerbot- can fit 4 on a plate.

The central "hole" is really just a pilot hole-drill out with a hand drill to somewhere between 1/16" and 1/8" depending on how big/powerful your balloons are. You want the minimum size of hole that will allow it to skim around. Bigger than that and it will run out of air too quickly.

Glue the bottom to the center of a CD.

Inflate a balloon, twist and hold the neck while you fit it over the rim.

Release and the CD skims around on a cushion of air for as long as the balloon lasts. Play games!