Three common methods, simplest first:
1. **Spring + wire**: wire passes over a roller on one side, attaches to a tension spring. Self-adjusts as wire heats up and expands.
2. **Threaded rod**: wire crimped to a screw eye, screw eye threaded through a fixed mount. Tighten by hand.
3. **Constant force spring**: small constant-force spring (Negator type) — fanciest, smoothest, ~€10.
Tension target: tight enough that gentle finger pressure deflects the centre <5mm on a 500mm span when cold. Wire expands ~1.5% from cold to working temp, so cold-tight = hot-loose.
1. **Spring + wire**: wire passes over a roller on one side, attaches to a tension spring. Self-adjusts as wire heats up and expands.
2. **Threaded rod**: wire crimped to a screw eye, screw eye threaded through a fixed mount. Tighten by hand.
3. **Constant force spring**: small constant-force spring (Negator type) — fanciest, smoothest, ~€10.
Tension target: tight enough that gentle finger pressure deflects the centre <5mm on a 500mm span when cold. Wire expands ~1.5% from cold to working temp, so cold-tight = hot-loose.