Craft & DIY

#24 · Suspend a mobile art installation

Balance chopsticks across each other to create the arms of a hanging mobile. Add paper shapes and step back to admire your work.

Baby mobiles, wind spinners and hanging sculptures all begin with the same problem: a cross-piece that is stiff enough not to sag and light enough to turn in a draught. Two chopsticks lashed at right angles are close to ideal.

How to do it

1. Cross two chopsticks at their centres and lash tightly with strong thread, wrapping in both directions.
2. Add a drop of glue at the lashing once you are happy, to stop it creeping.
3. Tie the hanging thread at the exact centre.
4. Hang it empty first and check it sits level.
5. Add your objects one at a time, adjusting positions along the arms until it balances after each addition.

Why it works

A mobile balances when the moments about the pivot cancel - weight multiplied by distance from centre, on each arm. That is why a heavy object close in balances a light one far out, and why adding one piece at a time works and adding all four at once does not.

Tips & warnings

• Use paperclips as temporary weights to find the balance point before you commit.
• Bamboo is stiff for its weight, which is what keeps the arms from drooping under load.
• Layer it - hang smaller crosses from the ends of the main one for a proper Calder effect.