Date: Wed Oct 21 08:37:46 2009

Author: Michael Timmins

Subject: Van de Graff Generator Rollers / Re: Fun Fly stick reengineering

Post:

It may be the black rubber belt. The best thing to do now is get an
electrometer and start rubbing rods with the belt to verify the proper
charge separation (that sounds nice, huh?). I'll have to get one of
these and play with it.


Mike Timmins

Physics Dept.
University of Virginia
382 McCormick Rd
Charlottesville, VA 22904
mat3q@virginia.edu




On Oct 20, 2009, at 3:56 PM, Irons, Stephen wrote:

> Well, I replaced the teflon roller with Nylon which should take on an
> opposite charge from that of teflon, cleaned the grease off of
> everything and put it back together and am getting absolutely no
> charge buildup.
>
> I guess my next move is to play around with the positioning of the
> combs. Any other ideas?
>
> Thanks to all for your suggestions.
>
> -Stephen.
>
> On Oct 14, 2009, at 9:32 AM, Zani, Gerald wrote:
>
>> Keep the aluminum roller at the wand end for both positive and
>> negative
>> charge versions.
>>
>> Make an acrylic roller to replace the Telfon roller at the motor end.
>> Acrylic and Teflon will produce opposite the opposite sign of charge
>> when rubbed with most materials.
>>
>> Acrylic takes on a net deficiency of electrons (+positive charge)
>> when
>> rubbed with most materials.
>> Teflon (and also PVC) take on a net excess of electrons (-negative
>> charge) when rubbed with most materials.
>>
>>
>>
>> - jz
>>
>>
>> -----Original Message-----
>> From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu]
>> On
>> Behalf Of Irons, Stephen
>> Sent: Tuesday, October 13, 2009 1:01 PM
>> To: tap-l@lists.ncsu.edu
>> Subject: [tap-l] Fun Fly stick reengineering
>>
>> Hello all,
>>
>> I bought two Fun Fly sticks a little while ago
>> (http://www.teachersource.com/ElectricityAndMagnetism/Electricity/FunFly
>> Stick.aspx?gclid=CLXZj_a9up0CFZho5QodJmXIjw
>> )
>>
>> and have wanted to reengineer one so that it puts the opposite charge
>> on the wand. So I finally got around to it this week. When I opened
>> one up I found a mini VdG generator, with a teflon roller at the
>> motor
>> end and an aluminum roller at the wand end with a black rubber belt
>> connecting the two. I had the shop adjust them so I could reverse
>> them
>> (teflon at the wand end and aluminum at the motor end). However
>> when I
>> turned it on, pretty much nothing happened. I got no charge buildup
>> at
>> all on the wand end. Is there something else I need to be doing?
>>
>> It looks like charge is being extracted from your body (an
>> approximate
>> ground) and transferred to the wand end so it didn't seem like I
>> would
>> need to rewire it.
>>
>> Any thoughts?
>>
>> Many thanks.
>>
>> -Stephen.
>>
>>
>> **********************************
>> Stephen Irons
>> Yale University
>> Director, Instructional Laboratories Department of
>> Physics
>> tel: 203-432-3664
>> P.O.
>> Box 208120
>> fax: 203-432-6175 New
>> Haven, CT 06520-8120
>>
>> COURIER DELIVERIES PLEASE USE
>> Yale University
>> Department of Physics
>> 217 Prospect Street
>> New Haven, CT 06520
>>
>>
>>
>
>


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