Have you ever went ice fishing and brought along some drinks with you, only to have them freeze in the snow? This telescoping device can be extended into the water, safely keeping your drinks just above freezing. Each cylinder is separately printed and tapered such that the device can either extend into the water or "fold" together into the height of one soda can. The final (top) cylinder includes a base that can be placed on top of the ice and be held down by weight or by bolts/screws.
This design is parametric and based in OpenSCAD. I printed a device with three cylinders to hold three drinks. This design required a unique top inner radius in OpenSCAD for each cylinder. The formula to properly change this radius for any design is detailed in the "Master" OpenSCAD file. I also included three OpenSCAD files with the specific parameters I used in my prints, as well as the STLs these files generated.
Overall, this print costs $12.12. The cost could be improved by reducing the cylinder thickness or cutting out parts of the cylinder. Friends have offered me $30 for this device, which still gives me a profit of $17.88 per device. If I could sell 23 of these (and take a little over a day to print each one), I could make up the cost of my RepRap-derived Athena II in a month!