The houseplants have migrated indoors after spending a summer charging up in the sun on the patio, which means it’s time to replace the silicone rubber feet on the bottom of the plant shelves. This year, I printed a set of feet to fit the hex-head adjustable feet:

The pencil-stem plant on the left, for whatever it’s worth, is a perfectly healthy Rhipsalis that greatly enjoyed the summer sun.
The feet print upside-down to give the surface around the hex a smooth finish. I used Slic3r’s Hilbert Curve for pattern a bit more interesting than the usual parallel lines:

The Hilbert curve doesn’t fit neatly into a non-rectangular shape, but it’s close enough.
The solid model includes the support structure:

Which pops out cleanly:

Yes, that’s a shred of red filament embedded on the left side. Cleanliness is next to impossible…
The fuzzy felt feet come from a 6 mm thick slab of the stuff:

The round socket wall leaves about 2 mm of felt showing at the bottom; it’s not very compressible and that should suffice to keep the plastic off the table.
The OpenSCAD source code:
// Feet for a wire-shelf plant stand
// Ed Nisley KE4ZNU October 2013
Layout = "Build"; // Show Build
Support = true;
//- Extrusion parameters must match reality!
// Print with 2 shells and 3 solid layers
ThreadThick = 0.25;
ThreadWidth = 0.40;
HoleWindage = 0.2;
Protrusion = 0.1; // make holes end cleanly
//----------------------
// Dimensions
StandFootOD = 18.0; // hex across flats
StandFootDepth = 5.0; // ... socket depth
FeltPadOD = 25.0; // felt foot diameter
FeltPadDepth = 4.0; // ... depth
FootBaseThick = 6*ThreadThick; // between foot and pad
FootWall = 4*ThreadWidth; // around exterior
FootOD = 2*FootWall + max(StandFootOD,FeltPadOD);
echo(str("Foot OD: ",FootOD));
FootTall = StandFootDepth + FootBaseThick + FeltPadDepth;
echo(str(" ... height: "),FootTall);
NumSides = 8*4;
//----------------------
// Useful routines
module FootPad() {
difference() {
cylinder(r=FootOD/2,h=FootTall,$fn=NumSides);
translate([0,0,FeltPadDepth + FootBaseThick])
PolyCyl(StandFootOD,2*StandFootDepth,6);
translate([0,0,-Protrusion])
PolyCyl(FeltPadOD,(FeltPadDepth + Protrusion),NumSides);
}
}
// Locating pin hole with glue recess
module LocatingPin() {
translate([0,0,-ThreadThick])
PolyCyl((PinOD + 2*ThreadWidth),2*ThreadThick,4);
translate([0,0,-(PinLength/2 + ThreadThick)])
PolyCyl(PinOD,(PinLength + 2*ThreadThick),4);
}
module PolyCyl(Dia,Height,ForceSides=0) { // based on nophead's polyholes
Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);
FixDia = Dia / cos(180/Sides);
cylinder(r=(FixDia + HoleWindage)/2,
h=Height,
$fn=Sides);
}
module ShowPegGrid(Space = 10.0,Size = 1.0) {
Range = floor(50 / Space);
for (x=[-Range:Range])
for (y=[-Range:Range])
translate([x*Space,y*Space,Size/2])
%cube(Size,center=true);
}
//-------------------
// Build it...
ShowPegGrid();
if (Layout == "Show")
FootPad();
if (Layout == "Build") {
translate([0,0,FootTall])
rotate([180,0,0])
FootPad();
if (Support)
color("Yellow")
for (Seg=[0:5]) {
rotate(30 + 360*Seg/6)
translate([0,0,(StandFootDepth - ThreadThick)/2])
cube([(StandFootOD - 3*ThreadWidth),
2*ThreadWidth,
(StandFootDepth - ThreadThick)],
center=true);
}
}