Piano stool riser

This is an extension for a piano stool (useful for children).
The interior (square) hole as well as the height and radius of the shim can be modified in the .scad file

Model infos :
floor diameter = 56 mm;
diameter = 50 mm;
square hole = 20 mm;
hole depth = 10 mm;
total height = 50 mm;

Printing infos :
Layer height = 0.2mm
Infill = 25%
No support