Halo
A counterweighted task light with no visible fasteners and no visible LEDs — designed to hold position for a decade without a single adjustment.
- Year
- 2022
- Category
- Lighting
- Role
- Industrial Designer
- Client
- Confidential — contract furniture brand
- Timeline
- 8 months, concept to production
- Team
- 1 ID, 2 ME, 1 lighting engineer
- Status
- In production since 2023
The brief
Contract furniture has a brutal economics problem for lighting: a lamp specified into an office fit-out will be adjusted by hundreds of different people over its life, and every spring-arm lamp on the market goes slack within two or three years of that treatment. The client's warranty data was unambiguous. Ninety-one percent of returns were arm droop.
The brief asked for a better spring. We proposed removing the spring. A counterweighted arm has no elastic element to fatigue — it is balanced by mass, and mass does not relax. The trade-off is that a counterweight is heavier, larger, and much less forgiving of manufacturing tolerance, because the balance is only as good as the geometry.
The second half of the brief was visual. This was a lamp destined for open-plan offices, dozens per floor, in a client's sightline all day. It needed to disappear. That drove the two hard rules the programme was judged against: no visible fastener anywhere on the product, and no direct view of an LED from any seated position.
What the research changed
Three findings did most of the work. Each one closed off a direction we had been treating as obvious, which is the only reliable sign that research is earning its budget. Methods: contextual inquiry across eighteen sites, competitive teardown of six units, and two rounds of formative testing with printed rigs.
Nobody adjusts a lamp twice
Observed users set a lamp on their first day and touched it again only if it drifted. Drift was the trigger for every subsequent interaction.
Glare is judged by neighbours
Complaints came overwhelmingly from people at adjacent desks, not from the lamp's own user.
Visible screws read as cheap
In a blind ranking of eight competitor lamps, fastener visibility predicted perceived price more reliably than material or finish did.
Four decisions that shaped it
Counterweight over spring
The arm balances around two pivots against a machined steel mass in the base. Friction is set by a pair of PTFE-faced thrust washers preloaded to a fixed torque at assembly, giving a consistent 0.9 N·m of motion resistance regardless of arm angle. It does not change over life because nothing in the load path is elastic.
Hiding every fastener
The die-cast arm halves close on a tongue-and-groove joint and are drawn together by two internal tie bolts accessible only through the pivot bore. Assembly happens in a fixed sequence that we designed alongside the factory — it is genuinely impossible to build in the wrong order, which was the only way to make a fastener-free exterior survive a real production line.
Optical design
A shallow reflector and a micro-prismatic diffuser put the emitter behind a 42° cut-off. From any seated position at an adjacent desk, you see illuminated surface and no source. The penalty is roughly 12% optical efficiency, paid for with a slightly larger emitter array.
Casting and finish
Arm and base are high-pressure die-cast in ADC12, machined at the pivots and shot-blasted before a two-coat powder finish. Draft, wall thickness and gate location were negotiated across four rounds with the caster; the final part has a 2.4 mm nominal wall and no visible parting line on any A-surface.
Specification
The long tail of the programme was tolerance stack-ups, part consolidation and assembly sequencing, run jointly with engineering. Headline figures from the released specification below.
Outcome
Numbers are the fastest way to make a case study credible, so include them even when they are modest. If a programme was cancelled, say so and say what you learned.
Credits
Work shown with permission. Some details altered or omitted under NDA.