This is an adapter for holding sandpaper with an oscillating multitool. I designed it for a DeWalt DCS356, but it may fit other brands/models with the same blade interface.
The Everclamp grid with sqwasher plate and thumbscrews lets you attach sandpaper, a sponge, or other irregularly-shaped objects in any orientation.
Do not print the "uncalibrated" STL files, as the threads will not fit. Instead, use OpenSCAD to convert the attached *.bundle.scad files into STL, calibrated for your printing setup. See https://everclamp.org/#calibration for instructions.
PrusaSlicer settings:
Layer height 0.2mm
Gyroid 15% infill
The elevated flat part requires good support to print correctly:
Support style: organic
Don't support bridges: unchecked (in other words, DO support bridges)
Overhang threshold: 10 degrees (support the bridge, not the screw threads)
Top/Bottom contact Z distance: 0.2 (detachable)
Top/Bottom interface layers: 3 (heavy)
Support speed: 20 mm/s (slow)
In other news, if you try to upload a file named uncalibrated_example.stl to Thingiverse, it fails with no error message, because somewhere they have a pr0n filter searching for rated*x.
Some people might find this bundle_scad.py code useful. It combines an STL, SCAD, and all its dependencies into a single file.
Bosch has a bunch that are quite useful for sanding in corners: https://www.boschtools.com/us/en/sanding-polishing-43817-ocs-ac/