Yup.  I tried that.  I found it to be simpler to use this beveled step:

//*************************************************************
module verticalHoleWithBevelStep( screwInfo, length, layerHeight )
//*************************************************************
// The default orientation has the screw head at the bottom, flush with
// the xy plane.
{
threadD = SCREW_HOLE_SCALE_FACTOR * screwInfo[0];
headD  = SCREW_HOLE_SCALE_FACTOR * screwInfo[1];
headZ  = SCREW_HOLE_SCALE_FACTOR * screwInfo[2];
adjustedLength = SCREW_HOLE_SCALE_FACTOR * length;

union()
{
cylinder( h=headZ, d=headD );

translate( [ 0, 0, headZ ] )
cylinder( h=3*layerHeight, d1=headD, d2=threadD );

cylinder( h=adjustedLength, d=threadD );

}
}
//*************************************************************

difference()
{
L_cube( [ 10,10,10], center="xy" );

verticalHoleWithBevelStep( Screw_info("M3"), 10 , 0.2 );
}

On Sat, May 20, 2023 at 3:17 PM jon jon@jonbondy.com wrote:

I’ve used that technique in the printable 3D printer design that inspired the BOSL and BOSL2 libraries. It’s unclear to me, however, how to genericize that pattern for a library, as it is extremely dependent on the shape of the area to be bridged.

-Revar

NopSCADlib can do it. You pass a child which is the 2D profile of the hole
below. It's called hanging hole

On Sun, 21 May 2023, 00:35 Revar Desmera, revarbat@gmail.com wrote:

I wrote about it, with cod and examples
https://www.reddit.com/r/openscad/comments/13nlnvk/images_to_go_with_how_to_3d_print_bores_without/

On Sat, May 20, 2023 at 1:18 PM jon jon@jonbondy.com wrote: