This is a mix between @JernejP's 90 degree No support model and @6d6178's Modular Mounting System Arms. I took the no support concept and applied it to the modular arms as I had better luck with those dimensions/tolerances. The result is virtually no cleanup required.
This is only the 30mm, 90 degree rotation version.
A brim is recommended, but can be printed without depending on bed adhesion.
The author remixed this model.