My favorite way to remove scratches after re-crowning frets is to use 400 and 600 grit sandpaper followed by quad 0 steel wool and Dremel tool buffing. My old fret sander has the disadvantages of not fitting my hand very well, and having a fret radius that was good for medium size frets but not smaller or larger diameter frets.
The idea for this tool comes from a YouTube video channel called The Next Project. The video links are youtube.com and youtube.com. I expanded and adapted ideas used in "The Grip" to make the FretSander. Many of the differences between the "The Grip" and the FretSander address reducing the friction of the sandpaper travel so it can use lower grits.
One of the FretSander features is the swappable fret caul insert. I've included a parametric design file so you can create custom sizes. To use, open Fusion 360, open FretCaulInsert.3fd, select MODIFY - Change Parameters, and change the 'fretdiameter' parameter. Remember to add the thickness of your sandpaper to the diameter of your frets. For example, my 400 grit paper is about .009", and my 600 grit paper is about .008" thick. The 'toleranceslip' parameter allows you to modify how tightly the fret caul insert fits in the FretSander handle.
I wanted the fret caul radius labels to automatically update, so I used a parametric text fusion add-on found here:
apps.autodesk.com
I've included a couple of ready to print .stl files for medium and large frets.
For FretSander handle slicer settings I used 0.20mm layer height and the variable layer height option to get smoother surface finish on contours. Print the sandpaper reel and fret caul inserts standing vertical for best results.
When holding the FretSander I use my thumb and index finger to gently squeeze and pull up on the sandpaper. This keeps the sandpaper from sliding around while sanding a fret. When its time to advance the sandpaper, I release finger pressure. The sandpaper reel is designed to turn counter clockwise to minimize sandpaper friction against the FretSander handle.
The paper cutter seen in the video was purchased from Harbor Freight just for cutting sandpaper strips. I've used it for several years and it still makes clean cuts.
Any resemblance between the FretSander and the Jawa sandcrawler is purely coincidental.
