Customizable delta calibration rings

I wanted to test how well I could print over the entire bed of my tevo little monster so I created a quick little openscad program to generate these rings for testing.

Each ring is 3 nozzle diameters wide a 3/4 of a nozzle diameter tall. With my default slicer settings that makes this a single layer test and only uses a little over 2m of filamnet.