Checking the balance of an Anglepoise sprung lamp

Checking the balance of an Anglepoise desk lamp

The primary function of an Anglepoise sprung desk lamp is to allow the user to position the shade and therefore provide light at the best position for them to accomplish the task in hand, reading a book, crafting, modelling, needle working etc.

The design uses opposing spring forces to create a positional equilibrium which allows the shade to magically hang in space. To maintain this the Anglepoise lamp relies on three key variables;

• The bulb fitted to the lamp should be in the correct weight range for the product 25~60g or 1~2¼ ounces in old money
• Three springs, the centre spring having a different spring rate to the outside 2 springs, the centre and outer springs cannot swap position
• Some small residual friction in the Anglepoise lamp arm system which can be tuned using the supplied hex keys or spanners.

Out of the box from new the Anglepoise lamp should arrive perfectly adjusted and ready to use, when testing for the first time we would recommend that you make sure the supplied bulb is fitted in the bulb holder, the balancing doesn’t work without the bulb.

Is my Anglepoise balanced correctly?

With the Anglepoise lamp assembled as shown in the instructions and with the bulb fitted, place it on a clean flat surface, lift the shade to its most extended upright position and let go, the shade should stay in position.

Next gently grab the front of the shade and pulling slowly extend the lamp to its maximum horizontal position, again let go, the shade should hold its position with little spring back.

In both instances the base should remain flat on the surface and should not move.

What to do if my Anglepoise does not balance ?

Common solutions

If the base is moving or tipping when trying to move the shade there is too much friction in the system. This will require some pivot screws to be loosened slightly, using the supplied hex keys and following the guidance in the user guide loosen the top arm screw (A) and both left and right fork arm screws (B) by around a quarter of a turn each then retest. Repeat the process if necessary. Once the base remains stable during movement of the shade the upright and full extension tests can then be done.

1. If when fully extended in the upright position the lamp starts to fall, tighten the top arm screw (A) and the link arm screw (C) around a quarter of a turn and retest, repeat until the lamp balances.
2. If when fully extended horizontally the lamp starts to rise tighten the left and right fork arm screws (B) around a quarter of a turn and retest, repeat until the lamp balances.