Please LMK if you have a better name for this simple tool!
4 and 6 inch mini paint rollers are very helpful for smaller projects, but there's no way to spin dry them in a mechanical spinner. Brushes fit into the holder and larger rollers slip over it, so I created a simple handle that slips into the spinner holder like a brush. I used a 140mm long, 6mm diameter rod for the mini roller to slide onto. 1/4" would work too, but you might need to scale the handle up if the fit is too tight. Glue it in with a bit of CNA glue or epoxy. No you can wash and dry mini rollers and reuse them. Photos of a mechanical spinner and mini rollers are included for reference.
Print this with the hole end down and consider using mouse-ear brims if you have adhesion issues with your print bed. PLA is fine, 20% infill worked for me.