Rollpad: Fridge notepad for roll of adding machine paper

This is a "notepad" for the fridge (though you could also use it, upside-down, placed on a table or desk). I designed it for rolls of paper that I have, which are:

* 2 1/4" (57cm) wide
* 2 5/8" (about 68cm) in diameter
* 1/2" (~8mm) diameter hole through the spool

**Print these parts:**
* main.stl (this is the main body of the thing; probably print with writing surface flat on build plate)
* cutter.stl (this is the paper cutter)
* cutter-post.stl X2 (or you can find some 4-5mm