This is an adapter to attach a Shimano shifter with ISPEC-EV interface to a Formula brake. For the brake the Formula Mixmaster is needed, because there the adapter attaches. Please be aware, that you will need a **left** side Mixmaster for the shifter on the right, due the way the two components are oriented to each other.
The shifter is attached to the adapter with a M4 screw. To make it stable, the adapter has a pocket for a M4 square nut. The clamp that holds the adapter to the stud of the Mixmaster has a pocket for a M3 square nut.
I printed it laying sideways with support under the square nose. Filament was PETG from 3D Jake.
Design was done in Onshape. It took several iterations until the position of the shifter relative to the brake lever felt comfortable.
(Note: had to select the Prusa I3, because the Prusa Mini is not in the list of printers)