These pieces are made to hack a Princess High Speed Deluxe blender into a centrifuge. The small piece is placed to rotate a metallic bar in the middle and the bigger one maintains the rotor in place. The two holes on the sides are for mainatining the piece with straps. The rotor I used was found on thingiverse https://www.thingiverse.com/thing:4583027.
More documentation on how the centrifuge was made on my documentation page https://class.textile-academy.org/2022/annah-sangosanya/FinalProject/04_MachineMaking/