Metronomes are used to help musicians keep time and for relaxation. They consist of a pendulum that swings back and forth and the mechanism that causes the pendulum to swing. Metronomes can be adjusted by sliding the weight up and down on the pendulum. This changes the tempo of the metronome. Though durable and highly reliable, metronomes do sometimes require repair. If you are fixing a metronome in your home, you will typically be either balancing the metronome or lubricating the spring and its mechanism.
Lubricating the Spring Mechanism
Ensure that the tab that keeps the pendulum from moving is firmly in place. Turn the metronome upside down so you have access to the panel at the bottom. Move the small tabs or brackets that hold the panel in place.
Using the flathead screwdriver, gently pry the panel away, revealing the inside of the metronome. You should see the gears, the spring mechanism and the weight at the bottom of the pendulum.
Look closely for the spot where the winding mechanism is connected to the gears. Using the precision spray tube, direct a small amount of WD40 to this spot. Do not use too much lubricant.
Wind the metronome while watching the mechanism. If you encounter resistance, wait ten minutes to allow the WD40 to loosen the spring and gears.
Try once more to wind the metronome. If it winds, replace the panel and proceed to balance the metronome. If the mechanism still will not wind, it is likely that you will have to replace the entire mechanism or purchase a new metronome.
Balancing Your Metronome
Place the metronome on a firm surface. The surface should be flat, like a table or counter. Ensure that the tab that keeps the pendulum from swinging is still in place.
Turn the winding mechanism clockwise at least four or five times. Be careful not to over-wind the mechanism. If you have previously wound the mechanism while lubricating your metronome, you will not have to wind it again. If you must wind it further, stop as soon as you encounter resistance, or you risk breaking the metronome beyond repair.
Release the pendulum from the tab that keeps it in place. Adjust the tempo rate to what is called presto, or between 168 and 200 beats per minute. If the pendulum does not swing, try placing a piece of paper under one side or another of the metronome to make it perfectly level. Fold the paper if necessary to make it slightly thicker. If the metronome cannot be balanced at home, seek out a qualified professional to repair it.
If the pendulum weight slides too freely, slightly tighten the screws on either side of the weight.
If you suspect that the gears need replacing on your metronome, take it to a clock repair shop. Metronome and clock gears are very similar and most shops will be able to help you.
Never disassemble the mechanism of your metronome. Fiddling with the innards of the metronome should be left to a professional.
Over-winding the metronome can cause the spring mechanism to break. Stop when you encounter resistance.