Table leveller for 21.5mm leg half centimeter height boost

This is quite simple, but I learned how to properly use ShapeBinders in FreeCAD to do it so it doesn't break with adjustment. Unfortunately I have to edit the freecad file to make adjustments so for the time being this is set to 5mm height boost and suits table legs that are 21.5mm steel pipe.

But the idea is applicable to many different wobbling tables so you can do likewise once you learn FreeCAD part design workbench.

Two important notes: 

1. MAKE SURE to but a chamfer on the inner surface of the wall to help guide the table leg in.
2. 15% infill is fine and plenty strong, you might think that you need 100% infill but you really don't.