Customizable Sifter with notch

Takes the original design and adds 3 small notches located inside to ensure that the various size-inserts don't easily popout (as the friction-fit didn't work for me).
The original model was also broken into individual printable parts, as I found greater success for printing, and also enabled better use of the colour gradient in the rainbow filament I used.
There is 0.1 test piece also included, this is just enough to ensure that the inserts fit into the clips, but is not necessary for printing.