Why Isn't It Solid?

The short version. The load goes through the screws, not the middle of the panel. Every bracket gets 1 mm solid walls around every edge and every screw hole, with 25% infill in between, so the plastic is where the work happens. Filling the middle would add weight with nothing to carry, and thick solid PETG cools unevenly and pulls its own layers apart.

1. Where the solid plastic is

Before any infill goes down, the print head traces the outline of each layer in solid plastic. That border is 1 mm thick, and it follows every contour on every layer. Outside edge, screw holes, all of it. Only what's left inside gets filled with lattice.

The wall follows every contour, holes included. Each screw hole gets the same 1 mm border, so there's a solid tube of PETG right where the screw clamps down. Not lattice.

Solid wall — 1 mm Infill — 25% Solid top & bottom faces

2. Where the clamping force goes

This is the one people worry about. The bracket builds up in 0.2 mm layers, and the screws pass through that solid 1 mm wall around each hole, not the infill next to it. So the clamping force runs straight down a column of solid plastic, from the screw head into your siding.

The load path never touches the lattice. Force goes from the screw head, down a solid column of PETG, into the siding. The infill sits beside that column, not under it.

3. What it actually has to resist

The reel doesn't hang off the MilliMount. It bolts to the Hoselink bracket, and that bolts through the MilliMount into your studs, so the MilliMount spends its life clamped flat against the wall with load reaching it through four lag screws.

Two things try to move it. The reel hangs out from the wall, so its weight wants to pry the top of the assembly away from the siding. And when you pull the hose sideways the reel swivels, which tries to twist the whole bracket in place.

Both of those land on the same four points. The plastic around each screw hole takes the load, and that's the part that's already solid. The open middle of the panel isn't in the load path at all, which is why filling it in doesn't buy you anything.

Every load lands on a screw hole. The reel's weight pries at the top pair, hose pull twists against all four. The middle of the panel is just spacing the reel off your siding, so plastic added there has nothing to carry.

There's a second problem with filling it in. Thick solid PETG shrinks as it cools, and on a part this size the outside sets before the core does. That pulls on the layers from the inside, and you end up with warping and tiny separations between layers. Which is exactly the kind of crack you were trying to avoid in the first place.

How it gets printed

Per bracket, as sliced
Material	UV-resistant PETG
Nozzle	0.4 mm
Layer height	0.2 mm
Wall thickness	1 mm
Infill	25%
Bracket size	126 × 215 mm
Weight	≈ 210 g
Print time	≈ 9 h 30 m

These are the settings our print shop publishes for their standard PETG service. They're fixed. The same profile runs on every part in the building, so a solid version isn't something we can order even if you wanted one. And as above, you wouldn't.

The settings above are the ones our production partner, Slant 3D, publishes for standard PETG: 0.2 mm layers, 1 mm walls, 25% infill, 0.4 mm nozzle, plus their design guide. Weight and print time are their own numbers for this part. How many passes make up that 1 mm wall isn't published anywhere, so we don't claim a figure.

Every MilliMount bracket is printed to order from your own siding measurements, and comes with a 1-year warranty against defects in material or workmanship.

1. Where the solid plastic is

2. Where the clamping force goes

3. What it actually has to resist

How it gets printed