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    • #12578
      Profile photo of Andrew Normand
    • #12579
      Profile photo of Andrew Normand

      When I had some trouble getting our aquadag onto  pingpong balls I ended up covering them entirely with graphite by using an HB pencil. Do you think this would be enough? They hold a charge quite happily like that.

    • #12580
      Profile photo of Andrew Normand

      Probably fine – I use softer pencils than this (multiple B’s) to draw conducting lines on paper for resistivity experiments.

    • #12581
      Profile photo of Andrew Normand

      Ah, we use these HB for that too so should be fine.

    • #12582
      Profile photo of Andrew Normand

      I think softer pencils might fade more easily, but I am sure placed like TimStar and even Maplin sell conductive paint. That should stick better, though probably more expensive.

    • #12583
      Profile photo of Andrew Normand

      I made one and tried it, didn’t get a great speed up but then it was a damp day so not a great one for the Van de Graaff. I tried it on a small induction coil but it was arcing between the ends of the aluminium. I might take it with us to the High Voltage Lab at Southampton, they have EHT supplies that go considerably further than our 5kV ones, might be interesting to see what can be achieved.

    • #12584
      Profile photo of Andrew Normand

      Thanks Dan.  It works!  Another great online workshop!!

    • #12585
      Profile photo of Andrew Normand

      Thanks for the demo Dan, it was very informative.  I’ll have to go away and source the materials now!

    • #12586
      Profile photo of Andrew Normand

      Thanks, Dan!  Looking forward to your next online workshop *hint hint*

    • #12587
      Profile photo of Andrew Normand

      Thak you Dan. How would you use the Van der graaf?

    • #12588
      Profile photo of Andrew Normand

      Hi Penelope

      I have posted this in the other thread on the discussion

      https://www.talkphysics.org/groups/5921/forums/5923#comment-16371

    • #12589
      Profile photo of Andrew Normand

      You connect a wire from the top of the dome to one set of aluminium foil with a croc clip e.g. the cross in the middle.

      Another wire goes from the earth on the Van der Graaf to the aluminium foil around the rim.

       

      Start the generator and the ball will move

    • #12590
      Profile photo of Andrew Normand

      Thanks Dan. Got a working version for under £4 not inc the ping pong ball. Salad/fruit bowl from Poundworld and a roll of Al tape from Maplin (£2.99). 

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