Thanks for the design. I like being able to do this in spiralize (Cura). I printed it first in red (top and bottom). I used the deeper notch version, but there seemed to be a lot of play between the top and bottom. In Cura, it looks like the bottom was 30mm diameter and the top was a little over 31.6mm. I reprinted another version resized by 0.5mm (a bottom 0.5mm bigger and a top 0.5mm smaller). The second print (black) fits perfect with the first. For my printer at least, either the top or botom should be resized by 0.5mm for a snug fit that slides easily.