This one uses clip mechanism to hold the sandpaper strip that you cut, and incorporates 9x11" standard sandpaper sizes.
You just have to strip the sandpaper according to your width, 20mm (1") wide is okay as well and clip them on each end, it is easy to adjust the sand paper tension.
There are 2 types of handle, 9" and 11". They literally mean how long you want your strip to be, either you use the 9" or 11" of your own strip.
All of the objects are symmetrical, print 2 of each parts.
You would require 8 M3x20 at least to assemble the whole thing.
I designed this to use a metal screw because of the sheer power of clamping needed to hold the sandpaper, a fully 3d printed clamp would just break too easily.
The author hasn't provided the model origin yet.