Adjustable feets for Height under the Form1+ printer

On my lightbox, (outlined here: A DIY UV post-cure Lightbox you too can make ) I used these adjustable felt feet:

What’s nice about them, is they don’t grip the surface, and allow easy spinning adjustment. They are not 6-32 though, so cannot go into the Form1+ directly. You could simply put them into a piece of plywood or MDF and set the form1+ on it though…