This will securely hold an M18 random orbital sander and should work with most other brands as well.
I recommend printing with four or so parameters for strength. No supports are necessary. The included holes are sized for #6 wood screws.
I have designed other similar holders for a variety of M18 tools.
Update 10/16/23 - as requested I have uploaded the Fusion 360 file.
The author marked this model as their own original creation.