Tech Note 1167 Detail

It is difficult to get a good charge on the Van de Graaf Generator.

Affected Products:

SE-8691 Van de Graaff Generator, High Voltage
SE-7355 Replacement Belt, Van de Graaff generator

Problem/Symptom:
It is difficult to get a good charge on the Van de Graaf Generator.

PASCO Solution:

For the best performance of your Van de Graaf Generator, you should replace the belt yearly because the rubber dries out, breaks down and won't build a charge.

Replacing the belt

  1. Wear a pair of rubber or latex gloves so you don't get any body oils on the belt. This is extremely important!
  2. Remove the 4 phillips head screws from the base of the Van de Graaff and lift the Van de Graaff off of the base.
  3. Lay the Van de Graaff carefully on the side.
  4. Move the wire brush slightly away from the wool pulley, enough so you can remove the rubber belt from the bottom pulley. Let the belt go up the plastic tube.
  5. Stand the Van de Graaff up and remove the top half of the dome from the Van de Graaff and set aside.
  6. Carefully bend the wire brush inside the dome back away from the plastic wheel on the top just a little.
  7. Lift up on the plastic wheel and remove the belt and pulley. You are going to carefully clean the top plastic pulley with a dry cloth and then place the new belt on the pulley.
  8. When you put the rubber belt in the plastic tube it only reaches about 1/2 way down the tube and is difficult to grab from the bottom so loop about a 1 to 2 meter length of cord over the inside of the new belt and dangle the cord down through the plastic tube so you can pull on the cord from the bottom to stretch the belt.
  9. Heat the bottom wool pulley with a hair dryer for about 15 minutes before looping the belt around the bottom pulley. This drives off any moisture in the pulley.
  10. Now carefully bend the two wire brushed back so they are 1/4 to 3/8 of an inch from the belt. Too small a gap and very little spark and too big a gap and no spark. Use a gap of one quarter of an inch.
  11. Replace the dome top and the 4 screws on the bottom. If you notice the pulleys are really worn or the wool looks old you may want to replace the pulleys.
  12. If you don't want to replace the belt, you can try heating the bottom pulley and the belt with a hair dryer for 20 - 30 minutes.

Creation Date: 03/20/2012
Last Modified: 03/20/2012
Mod Summary: