This is a model from a while back I made because I thought it was cool. This is called a level winding mechanism. you see these typically in fishing rods and winches and winding equipment to control where the line or whatever is getting wound goes so it is easier to unwind later.
This was also designed using my old printer (R.I.P. Barry) whose slicing program generated really annoying supports so i designed some in myself for the nub and the barrel pieces. You need 6 short #8 screws, one 5/16″ wooden dowel and another 3/8″ dowel. The thingiverse number is here.
Here’s a video: