The Van de Graaff generator: perfect for teaching static electricity … and for making your students’ hair look like Kramer’s or Einstein’s.
But that’s not this machine’s only eccentricity; she’s a bit of a diva—and she knows it. This equipment can require a delicate touch, so we’ve put together a troubleshooting guide to help you with any Van de Graaff model in your classroom or lab.
If your Van de Graaff generator is playing “hard to get,” then just follow these five simple steps:
If you use your Van de Graaff generator a lot, or it’s been in storage a long time, then dust and lint could’ve collected on the belt, pulley, and comb. That'll cause charge leakage on the collector sphere.
Clean the sphere inside and out, using a soft cloth and methanol to remove any dust, lint, and grease or oil deposits. Methanol evaporates quickly, so you can use the generator again in a jiffy.
It’s a dirty job, but somebody has to do it.
2. Replace the Belt
Has it been a year or more since you started using your Van de Graaff generator? You might need to replace the belt. Just don’t keep more than one spare belt on hand at a time, since their shelf life is limited.
Old belts degrade and may leave residue on the upper pulley. Every time you replace the belt, clean the pulley.
New belts could have oil or grit on them from the manufacturing process. Before installing the new belt, clean it—as described in step one.
If the belt’s too tight, the charge may not accumulate properly. So, before you install it, stretch the belt twice, gently but firmly.
3. Adjust the Collector Comb
Whenever you replace a belt, the position of the comb can slightly change. Readjust it to make sure the comb doesn’t scrape against the belt.
The best spacing between the belt and the comb can vary from 2 mm to 6 mm, depending on the model.
Give her some space, and she just might come back to you.
4. Check the Bottom Pulley
The lower pulley has felt or felt-like material that can absorb moisture during storage (or on humid days), inhibiting the accumulation of charge.
To fix this, remove the belt to expose the bottom pulley. Then run the motor at a low speed while directing a hairdryer (set at low heat) at the pulley for 20 to 30 minutes. Caution: Keep the dryer at a safe distance so the heat dries only the pulley and doesn’t damage anything.
The surface of the lower pulley could become matted or smooth and may need to be “fluffed up” to raise the nap. Place the loop part of a Velcro strip on the material, and pull it straight off the pulley. That’ll raise the fibers and allow a better flow of charge.
If the lower pulley is made of Teflon, clean it with a soft cloth, occasionally using methanol.
5. Check the Dome
The dome should be dent-free and smooth, without any burrs or sharp points.
Gently knock out any dents. Smooth any burrs with a fine-grit sand paper. Then wipe with a soft cloth and methanol.
Smooth, shallow dents shouldn’t affect performance much.
Follow these troubleshooting steps for your Van de Graaff generator, and she’ll be showing you love again before you know it!
If you’re still stuck or have any questions about Van de Graaff generators (or anything else), just ask the Ward’s Science Plus Us team at firstname.lastname@example.org. Our in-house scientists and technicians are ready to answer even the toughest questions.