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Metoden

One line, and it never stops.

This is the whole of how a Ljusverk shade is made, in the order it happens. There is no assembly step at the end because there is nothing to assemble.

Vase mode

Most 3D printing lays down a perimeter, fills it in, lifts the nozzle, travels, and starts again — hundreds of stops and starts per layer, each one a place where the plastic can under- or over-extrude. A shade needs none of that. It is a single wall, so the head can trace one closed contour and then simply keep going.

The trick is what happens to Z. Instead of stepping up between layers, it climbs continuously: exactly 0.28 mm over each revolution. So the object is not 3 214 rings stacked on top of one another. It is one helix, 2 793 metres long, and the wall has no horizontal join anywhere in it because there is nowhere for one to be.

What that buys, in order: a continuous visible spiral; a wall that is nominally 0.8 mm everywhere; a consistent printed surface; and a shade that weighs 778 g instead of the two and a half kilos an injection-moulded equivalent would.

The contour
r(θ, z)base(z) + amp · ridge(lobes·(θ + twist·z))
base(z)Interpolated shade profile
Z per revolution0.28 mm, always
Feed62 mm/s along the wall
Retractions0
Travel moves0
Density1.243 g/cm³

That first row is the entire industrial design of a Ljusverk lamp. Change the profile measurements and you have a different lamp; change nothing else.

TJÄLE drawn as its own toolpath

Drawn from the same numbers

This is TJÄLE — 3 076 metres, 2 214 layers, sixteen square-shouldered flutes on a slow twist. Follow the spiral, shown as a layered drawing. The changing density of the lines lets you see how the flutes overlap as the shade turns.

Drag it to turn it. The dial in the header dims it, and takes it from 2700 K down to 1800 K on the way, which is what the LK‑9 does.

Fourteen hours, in six parts

  1. Z 0.00 mm

    The purge line

    Every print starts with a 180 mm line laid down at the front of the plate that is not part of the object. It gets the pressure up and it tells the operator, in one glance, whether the material is dry. A purge line with a rough edge means the granulate has taken water out of the air overnight and the batch goes back to the dryer.

  2. Z 0.28 mm

    The first layer

    One closed contour, laid at 40 % of normal speed on to a plate at 62 °C. This is the only layer that touches the machine, and it is the only one that can fail quietly — a shade that lifts a millimetre at the edge finishes eight hours later, out of round, and looks perfect until you set it down.

  3. Z 0.28 → h

    The helix

    From here the head does not stop. Z climbs by exactly one layer height over each revolution, so what is printed is not a stack of rings but a single helix. Nothing retracts, nothing travels, and there is no seam anywhere in the wall because there is nowhere for one to be.

  4. the Z‑seam

    The one place it steps

    A spiral has to step up somewhere, and that step is the Z‑seam: a 0.28 mm ramp that runs the height of the shade. Most printers hide it behind a corner. We twist it — 0.16° per millimetre on SPIRA — so it walks around the object and reads as a slow helical line of light instead of a scar down one side.

  5. cooling

    Two fans, and patience

    A 0.8 mm wall at 0.28 mm layers is laying material on to material that is 1.4 seconds old. Too much cooling and the layers do not weld; too little and the flutes slump. The chamber runs at 38 °C and the part fans at 55 %, and both numbers were found by breaking about forty shades.

  6. the rim

    The last revolution

    The flutes fade out over the final six per cent of the height so the rim closes as a clean circle, and the flow tapers to zero over the last 40 mm. Then the head lifts and the shade is finished: no join, no glue, no fasteners, and nothing to take apart.

STAV 1100

Jonas built the first one over the winter of 2018 in a garage in Ersboda, because nothing sold at the time would print 1 100 mm tall and nothing sold at the time was designed to run for fourteen hours without a single retraction. A delta has no moving bed, which matters when the object is a metre of unsupported wall: nothing about the print is ever accelerated sideways.

There are 38 of them now, all built here, all running the same firmware. Machine 01 is still in the row.

STAV 1100
TypDelta, tre torn, linjärskenor
ByggvolymØ 520 × 1 100 mm
Munstycke0.8 mm härdat stål
Lagerhöjd0.20 – 0.32 mm
Väggtjocklek0.8 mm — en vägg, ingen ifyllnad
Matning62 mm/s längs väggen
Kammare38 °C, torkad luft
StyrsystemEgen firmware; 32-bit, 200 kHz stegpuls
Byggda38 stycken, alla i Sävar
Maskin 01byggd vintern 2018/19 i ett garage i Ersboda; 1 906 skärmar