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Hello Grayco4

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  • drj11642
    Check out my last 3 photos [drj11642 s toys]. I installed the shields and so far no difference. I plan on trying again after I paint all edges with corona
    Message 1 of 13 , Feb 1, 2012
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      Check out my last 3 photos [drj11642's toys]. I installed the shields and so far no difference. I plan on trying again after I paint all edges with corona dope.

      Doug J
    • Lyonel T. Adam Baum
      Hello Doug, what Corona Dope do you use ? GR Corona Dope ? Glyptal ? Or something else ?
      Message 2 of 13 , Feb 2, 2012
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        Hello Doug,

        what Corona Dope do you use ? GR Corona Dope ? Glyptal ? Or something else ?


        --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" <drj11642@...> wrote:
        >
        > Check out my last 3 photos [drj11642's toys]. I installed the shields and so far no difference. I plan on trying again after I paint all edges with corona dope.
        >
        > Doug J
        >
      • DOUG
        Hi Lyonel, I have been using corona dope from GC electronics. I have also ordered some Red X From Suburban electronics which should arrive soon. _____ From:
        Message 3 of 13 , Feb 2, 2012
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          Hi Lyonel,

           

          I have been using corona dope from GC electronics. I have also ordered some Red X From Suburban electronics which should arrive soon.

           


          From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of Lyonel T . Adam Baum
          Sent: T hursday, February 02, 2012 4:44 AM
          To: VanDeGraaffGenerator@yahoogroups.com
          Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

           

           

          Hello Doug,

          what Corona Dope do you use ? GR Corona Dope ? Glyptal ? Or something else ?

          --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" <drj11642@...> wrote:

          >
          > Check out my last 3 photos [drj11642's toys]. I installed the shields and
          so far no difference. I plan on trying again after I paint all edges with corona dope.
          >
          > Doug J
          >

        • DOUG
          A person really has to shop for this stuff [corona dope] as prices can double from one vender to another. I just paid $8.79 for 2 oz. from Suburban and GC
          Message 4 of 13 , Feb 2, 2012
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            A person really has to shop for this stuff [corona dope] as prices can double from one vender to another. I just paid $8.79 for 2 oz. from Suburban and GC wanted $17 for the same stuff.

             

            Doug J.

             


            From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of Lyonel T . Adam Baum
            Sent: T hursday, February 02, 2012 4:44 AM
            To: VanDeGraaffGenerator@yahoogroups.com
            Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

             

             

            Hello Doug,

            what Corona Dope do you use ? GR Corona Dope ? Glyptal ? Or something else ?

            --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" <drj11642@...> wrote:

            >
            > Check out my last 3 photos [drj11642's toys]. I installed the shields and
            so far no difference. I plan on trying again after I paint all edges with corona dope.
            >
            > Doug J
            >

          • GlenR
            Hello Doug, I have been looking at your photos and I have a couple comments. The fact that your brushes are actually dragging on the belt indicates to me that
            Message 5 of 13 , Feb 9, 2012
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              Hello Doug, I have been looking at your photos and I have a couple comments.

              The fact that your brushes are actually dragging on the belt indicates to me that you are generating a charge by the triboelectric effect between your brush(s) and the belt. The way these things are suppose to work is that the belt being in contact with the roller and then being separated creates a charge on that roller, usually positive. (read about an electrophorus) The brush/comb, which does not contact the belt, has a charge, usually negative, on it. The charge on the brush/comb ionizes the air between the brush/comb and the belt. The ionized air provides a path for electrons to flow toward the positively charged roller. The moving belt is between the brush/comb and the roller and the negative charge attaches to the belt and is conveyed to the upper brush/comb and with the help of the ice pail effect of the sphere is removed from the belt.

              What you have is a true triboelectric machine. If you were to remove your "supply brush" and just hold a piece of animal fur, or at the other end of the series, a piece of styrofoam, against the belt, I believe you will still see a charge.

              The other thing I notice is that your belt is pretty thick (looks like it may be a nylon reinforced neoprene). That may be reducing the ability of the charge on the roller to attract the charge on the brush/comb.

              These are the materials that Dick Linder recommends. (Except Dick uses white belt material. The McMaster Carr number for the belt material is for black, which has been used sucessfully by others)

              Belt is vinyl laminated nylon (McMaster-Carr 8810K141)
              The upper roller is Teflon
              The lower roller is nylon

              The belt material is only .015" thick. I'm going to order some in the next couple days. if you would like I could send you a piece to experiment with.

              One question. Did you put the Faraday shield on the supply side or the collection side? It should be on the collection side.

              You've done some awesome work on this fixture it really looks good. I especially like the way you handled the copper on the brushes.

              Good luck

              Glen

              --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" <drj11642@...> wrote:
              >
              > Check out my last 3 photos [drj11642's toys]. I installed the shields and so far no difference. I plan on trying again after I paint all edges with corona dope.
              >
              > Doug J
              >
            • DOUG
              Hello Glen; The belt is Mcmaster carr # 8981k112 - Medium-strength Neoprene Rubber, 3/32 Thk, 2 w, 36 l, Black, 30a Duro, Plain Back. I tried some 1/16 of
              Message 6 of 13 , Feb 9, 2012
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                Hello Glen; T he belt is Mcmaster carr # 8981k112 - Medium-strength Neoprene Rubber, 3/32" T hk, 2"w, 36"l, Black, 30a Duro, Plain Back. I tried some 1/16” of the same stuff and lost 5 microamps .

                Some interesting results with my VDG test fixture.

                 

                Parameters;

                Rollers = 1-1/2” diameter, 18” on center. Pos. is solid aluminum, neg. is acrylic.

                Belt = 2” wide X 3/32” thick Neoprene.

                • Brushes = Permanent conductive polyethylene. Surface resistivity: ≤ 102 ohms/sq.  Volume resistivity: < 300 ohms/cm.
                • T he brushes contact the belt.

                Belt speed = 412 Rpm. On the belt.

                With this setup current was 14 microamps.

                When I switched to saw tooth brass shim stock brushes current dropped to 12 microamps.

                I also tried a fitness band belt with the polyethylene brushes and current droped to 8 microamps

                I changed the Pos. roller from solid Alum. T o acrylic with foil wrap and gained 3 Microamps [now at 17 microamps]

                Changed pos. roller to nylon 6/6, dropped 5 microamps

                So now Neg. roller is PVC, Pos. roller is acrylic with foil wrap and fixture now is at 19 microamps

                I was introduced to the conductive film by Prof. Kevin Dunn [http://www.cavemanchemistry.com/kmd.html] he uses it on his Dirod machines.

                I tried it on the neutralizers on  my wimshurst machines and it worked, so then I used it for the pickups and it also worked, better than the combs!

                The problem with the usual way of using fine wire on the  neutralizers is that it would scratch the sectors, the film does not.

                My EMAIL is  drj11642@... if you send me your address I will send a sample of the film to try.

                PS,

                I would need a piece of the belt material 2” X about 40” to make a belt for my fixture, that is quite a lot for you to give away!

                Thank you for your comments.

                Doug J.

                 

                 

                 


                From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of GlenR
                Sent: T hursday, February 09, 2012 7:11 AM
                To: VanDeGraaffGenerator@yahoogroups.com
                Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

                 

                 



                Hello Doug, I have been looking at your photos and I have a couple comments.

                T he fact that your brushes are actually dragging on the belt indicates to me that you are generating a charge by the triboelectric effect between your brush(s) and the belt. T he way these things are suppose to work is that the belt being in contact with the roller and then being separated creates a charge on that roller, usually positive. (read about an electrophorus) T he brush/comb, which does not contact the belt, has a charge, usually negative, on it. T he charge on the brush/comb ionizes the air between the brush/comb and the belt. T he ionized air provides a path for electrons to flow toward the positively charged roller. T he moving belt is between the brush/comb and the roller and the negative charge attaches to the belt and is conveyed to the upper brush/comb and with the help of the ice pail effect of the sphere is removed from the belt.

                What you have is a true triboelectric machine. If you were to remove your "supply brush" and just hold a piece of animal fur, or at the other end of the series, a piece of styrofoam, against the belt, I believe you will still see a charge.

                T he other thing I notice is that your belt is pretty thick (looks like it may be a nylon reinforced neoprene). T hat may be reducing the ability of the charge on the roller to attract the charge on the brush/comb.

                T hese are the materials that Dick Linder recommends. (Except Dick uses white belt material. T he McMaster Carr number for the belt material is for black, which has been used sucessfully by others)

                Belt is vinyl laminated nylon (McMaster-Carr 8810K141)
                T he upper roller is T eflon
                T he lower roller is nylon

                T he belt material is only .015" thick. I'm going to order some in the next couple days. if you would like I could send you a piece to experiment with.

                One question. Did you put the Faraday shield on the supply side or the collection side? It should be on the collection side.

                You've done some awesome work on this fixture it really looks good. I especially like the way you handled the copper on the brushes.

                Good luck

                Glen

                --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" <drj11642@...> wrote:

                >
                > Check out my last 3 photos [drj11642's toys]. I installed the shields and
                so far no difference. I plan on trying again after I paint all edges with corona dope.
                >
                > Doug J
                >

              • Steven Dufresne
                Hi Doug, That brings up a good question... Since your brush is conductive polyethylene that brings up an interesting question - does its conductivity effect
                Message 7 of 13 , Feb 9, 2012
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                  Hi Doug,
                  That brings up a good question...
                  Since your brush is "conductive" polyethylene that brings up an
                  interesting question - does its conductivity effect the triboelectric
                  effect? Do you have a spare piece you could rub against
                  something triboelectrically positive? You could then test by
                  putting the polyethylene near arm hair or an electroscope if
                  you have one. Maybe repeat the test with some non-conductive
                  polyethylene.
                  -Steve
                  http://rimstar.org

                  -----Original Message-----
                  From: GlenR grayco4@...
                  Sent 2/9/2012 7:11:07 AM
                  To: VanDeGraaffGenerator@yahoogroups.com
                  Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

                  Hello Doug, I have been looking at your photos and I have a couple comments.

                  The fact that your brushes are actually dragging on the belt indicates to me that you are generating a charge by the triboelectric effect between your brush(s) and the belt. The way these things are suppose to work is that the belt being in contact with the roller and then being separated creates a charge on that roller, usually positive. (read about an electrophorus) The brush/comb, which does not contact the belt, has a charge, usually negative, on it. The charge on the brush/comb ionizes the air between the brush/comb and the belt. The ionized air provides a path for electrons to flow toward the positively charged roller. The moving belt is between the brush/comb and the roller and the negative charge attaches to the belt and is conveyed to the upper brush/comb and with the help of the ice pail effect of the sphere is removed from the belt.

                  What you have is a true triboelectric machine. If you were to remove your "supply brush" and just hold a piece of animal fur, or at the other end of the series, a piece of styrofoam, against the belt, I believe you will still see a charge.

                  The other thing I notice is that your belt is pretty thick (looks like it may be a nylon reinforced neoprene). That may be reducing the ability of the charge on the roller to attract the charge on the brush/comb.

                  These are the materials that Dick Linder recommends. (Except Dick uses white belt material. The McMaster Carr number for the belt material is for black, which has been used sucessfully by others)

                  Belt is vinyl laminated nylon (McMaster-Carr 8810K141)
                  The upper roller is Teflon
                  The lower roller is nylon

                  The belt material is only .015" thick. I'm going to order some in the next couple days. if you would like I could send you a piece to experiment with.

                  One question. Did you put the Faraday shield on the supply side or the collection side? It should be on the collection side.

                  You've done some awesome work on this fixture it really looks good. I especially like the way you handled the copper on the brushes.

                  Good luck

                  Glen

                  --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" drj11642@... wrote:

                  Check out my last 3 photos [drj11642's toys]. I installed the shields and so far no difference. I plan on trying again after I paint all edges with corona dope.

                  Doug J
                • DOUG
                  Hi Steve; I could be wrong, but I think the Poly. Is doing nothing more than being a very good medium to pick up the charge from the belt. Rubbing it on
                  Message 8 of 13 , Feb 9, 2012
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                    Hi Steve; I could be wrong, but I think the Poly. Is doing nothing more than being a very good medium to pick up the charge from the belt. Rubbing it on ,anything, has no more effect than if it was a piece of metal.

                     

                    Doug J

                     

                     


                    From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of Steven Dufresne
                    Sent: T hursday, February 09, 2012 10:37 AM
                    To: VanDeGraaffGenerator@yahoogroups.com
                    Subject: Re: [VanDeGraaffGenerator] Re: Hello Grayco4

                     

                     

                    Hi Doug,
                    T hat brings up a good question...
                    Since your brush is "conductive" polyethylene that brings up an
                    interesting question - does its conductivity effect the triboelectric
                    effect? Do you have a spare piece you could rub against
                    something triboelectrically positive? You could then test by
                    putting the polyethylene near arm hair or an electroscope if
                    you have one. Maybe repeat the test with some non-conductive
                    polyethylene.
                    -Steve
                    http://rimstar.org

                    -----Original Message-----
                    From: GlenR grayco4@...
                    Sent 2/9/2012 7:11:07 AM
                    T o: VanDeGraaffGenerator@yahoogroups.com
                    Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

                    Hello Doug, I have been looking at your photos and I have a couple comments.

                    T he fact that your brushes are actually dragging on the belt indicates to me that you are generating a charge by the triboelectric effect between your brush(s) and the belt. T he way these things are suppose to work is that the belt being in contact with the roller and then being separated creates a charge on that roller, usually positive. (read about an electrophorus) T he brush/comb, which does not contact the belt, has a charge, usually negative, on it. T he charge on the brush/comb ionizes the air between the brush/comb and the belt. T he ionized air provides a path for electrons to flow toward the positively charged roller. T he moving belt is between the brush/comb and the roller and the negative charge attaches to the belt and is conveyed to the upper brush/comb and with the help of the ice pail effect of the sphere is removed from the belt.

                    What you have is a true triboelectric machine. If you were to remove your "supply brush" and just hold a piece of animal fur, or at the other end of the series, a piece of styrofoam, against the belt, I believe you will still see a charge.

                    T he other thing I notice is that your belt is pretty thick (looks like it may be a nylon reinforced neoprene). T hat may be reducing the ability of the charge on the roller to attract the charge on the brush/comb.

                    T hese are the materials that Dick Linder recommends. (Except Dick uses white belt material. T he McMaster Carr number for the belt material is for black, which has been used sucessfully by others)

                    Belt is vinyl laminated nylon (McMaster-Carr 8810K141)
                    T he upper roller is T eflon
                    T he lower roller is nylon

                    T he belt material is only .015" thick. I'm going to order some in the next couple days. if you would like I could send you a piece to experiment with.

                    One question. Did you put the Faraday shield on the supply side or the collection side? It should be on the collection side.

                    You've done some awesome work on this fixture it really looks good. I especially like the way you handled the copper on the brushes.

                    Good luck

                    Glen

                    --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" drj11642@... wrote:

                    Check out my last 3 photos [drj11642's toys]. I installed the shields and so far no difference. I plan on trying again after I paint all edges with corona dope.

                    Doug J

                  • Steven Dufresne
                    Hi Doug, Interesting. Did you rub something else against whatever you rubbed the poly against? Just in case the problem was humidity or grease or some other
                    Message 9 of 13 , Feb 9, 2012
                    • 0 Attachment
                      Hi Doug,
                      Interesting. Did you rub something else against whatever you
                      rubbed the poly against? Just in case the problem was humidity
                      or grease or some other coating. I know when I rub vinyl against
                      a drinking glass I first have to clean the glass thoroughly otherwise
                      I get no charging.
                      -Steve
                      http://rimstar.org

                      -----Original Message-----
                      From: DOUG drj11642@...
                      Sent 2/9/2012 11:49:19 AM
                      To: VanDeGraaffGenerator@yahoogroups.com
                      Subject: RE: [VanDeGraaffGenerator] Re: Hello Grayco4

                      Hi Steve; I could be wrong, but I thinkthe Poly. Is doing nothing more than being a very good medium to pick up thecharge from the belt. Rubbing it on ,anything, has no more effect than if itwas a piece of metal.

                      Doug J

                      From: VanDeGraaffGenerator@yahoogroups.com [mailto:VanDeGraaffGenerator@yahoogroups.com] On Behalf Of Steven Dufresne
                      Sent: Thursday,February 09, 2012 10:37 AM
                      To: VanDeGraaffGenerator@yahoogroups.com
                      Subject: Re:[VanDeGraaffGenerator] Re: Hello Grayco4

                      Hi Doug,
                      That brings up a good question...
                      Since your brush is conductive polyethylene that brings up an
                      interesting question - does its conductivity effect the triboelectric
                      effect? Do you have a spare piece you could rub against
                      something triboelectrically positive? You could then test by
                      putting the polyethylene near arm hair or an electroscope if
                      you have one. Maybe repeat the test with some non-conductive
                      polyethylene.
                      -Steve
                      http://rimstar.org

                      -----Original Message-----
                      From: GlenR grayco4@...
                      Sent 2/9/2012 7:11:07 AM
                      To: VanDeGraaffGenerator@yahoogroups.com
                      Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

                      Hello Doug, I have been looking at your photos and I have a couple comments.

                      The fact that your brushes areactually dragging on the belt indicates to me that you are generating a chargeby the triboelectric effect between your brush(s) and the belt. The way these things are suppose to work is that thebelt being in contact with the roller and then being separated creates a chargeon that roller, usually positive. (read about an electrophorus) The brush/comb, which does not contact the belt, hasa charge, usually negative, on it. Thecharge on the brush/comb ionizes the air between the brush/comb and the belt. The ionized air provides a path for electrons toflow toward the positively charged roller. Themoving belt is between the brush/comb and the roller and the negative chargeattaches to the belt and is conveyed to the upper brush/comb and with the helpof the ice pail effect of the sphere is removed from the belt.

                      What you have is a true triboelectric machine. If you were to remove yoursupply brush and just hold a piece of animal fur, or at the otherend of the series, a piece of styrofoam, against the belt, I believe you willstill see a charge.

                      The other thing I notice is thatyour belt is pretty thick (looks like it may be a nylon reinforced neoprene). That may be reducing the ability of the charge onthe roller to attract the charge on the brush/comb.

                      These are the materials that Dick Linderrecommends. (Except Dick uses white belt material. TheMcMaster Carr number for the belt material is for black, which has been usedsucessfully by others)

                      Belt is vinyl laminated nylon (McMaster-Carr 8810K141)
                      The upper roller is Teflon
                      The lower roller is nylon

                      The belt material is only .015thick. I'm going to order some in the next couple days. if you would like Icould send you a piece to experiment with.

                      One question. Did you put the Faraday shield on the supply side or thecollection side? It should be on the collection side.

                      You've done some awesome work on this fixture it really looks good. Iespecially like the way you handled the copper on the brushes.

                      Good luck

                      Glen

                      --- In VanDeGraaffGenerator@yahoogroups.com,drj11642 drj11642@... wrote:

                      Check out my last 3 photos [drj11642's toys]. I installed the shields and sofar no difference. I plan on trying again after I paint all edges with coronadope.

                      Doug J
                    • Richard Linder
                      Hi All: FYI the best I can determine is the material I used for the belt is McMaster-Carr 8810IK123. It is nylon therefore no appreciable stretch. After a
                      Message 10 of 13 , Feb 12, 2012
                      • 0 Attachment

                        Hi All:    FYI the best I can determine is the material I used for the belt is McMaster-Carr  8810IK123. It is nylon therefore no appreciable stretch. After a bit of a “run in” the belt rides vey well on a slightly crowned roller. It is white therefore unlikely there is any conductive die used for coloration, It is vinyl which electrostatically proper and is weldable with acetone base plexi cement and the splice remains flexible. BTW he splice should be at an angle so it does not cross the roller all at once. I made two belts for the big VDG, one as a spare. I am still on the first belt after almost three years of lots of demos. 

                         

                        Dick

                         


                        From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of DOUG
                        Sent: Thursday, February 09, 2012 9:36 AM
                        To: VanDeGraaffGenerator@yahoogroups.com
                        Subject: RE: [VanDeGraaffGenerator] Re: Hello Grayco4

                         

                         

                        Hello Glen; T he belt is Mcmaster carr # 8981k112 - Medium-strength Neoprene Rubber, 3/32" T hk, 2"w, 36"l, Black, 30a Duro, Plain Back. I tried some 1/16” of the same stuff and lost 5 microamps .

                        Some interesting results with my VDG test fixture.

                         

                        Parameters;

                        Rollers = 1-1/2” diameter, 18” on center. Pos. is solid aluminum, neg. is acrylic.

                        Belt = 2” wide X 3/32” thick Neoprene.

                        • Brushes = Permanent conductive polyethylene. Surface resistivity: ≤ 102 ohms/sq.  Volume resistivity: < 300 ohms/cm.
                        • T he brushes contact the belt.

                        Belt speed = 412 Rpm. On the belt.

                        With this setup current was 14 microamps.

                        When I switched to saw tooth brass shim stock brushes current dropped to 12 microamps.

                        I also tried a fitness band belt with the polyethylene brushes and current droped to 8 microamps

                        I changed the Pos. roller from solid Alum. T o acrylic with foil wrap and gained 3 Microamps [now at 17 microamps]

                        Changed pos. roller to nylon 6/6, dropped 5 microamps

                        So now Neg. roller is PVC, Pos. roller is acrylic with foil wrap and fixture now is at 19 microamps

                        I was introduced to the conductive film by Prof. Kevin Dunn [http://www.cavemanchemistry.com/kmd.html] he uses it on his Dirod machines.

                        I tried it on the neutralizers on  my wimshurst machines and it worked, so then I used it for the pickups and it also worked, better than the combs!

                        T he problem with the usual way of using fine wire on the  neutralizers is that it would scratch the sectors, the film does not.

                        My EMAIL is  drj11642@... if you send me your address I will send a sample of the film to try.

                        PS,

                        I would need a piece of the belt material 2” X about 40” to make a belt for my fixture, that is quite a lot for you to give away!

                        T hank you for your comments.

                        Doug J.

                         

                         

                         


                        From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of GlenR
                        Sent: T hursday, February 09, 2012 7:11 AM
                        T o: VanDeGraaffGenerator@yahoogroups.com
                        Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

                         

                         



                        Hello Doug, I have been looking at your photos and I have a couple comments.

                        T he fact that your brushes are actually dragging on the belt indicates to me that you are generating a charge by the triboelectric effect between your brush(s) and the belt. T he way these things are suppose to work is that the belt being in contact with the roller and then being separated creates a charge on that roller, usually positive. (read about an electrophorus) T he brush/comb, which does not contact the belt, has a charge, usually negative, on it. T he charge on the brush/comb ionizes the air between the brush/comb and the belt. T he ionized air provides a path for electrons to flow toward the positively charged roller. T he moving belt is between the brush/comb and the roller and the negative charge attaches to the belt and is conveyed to the upper brush/comb and with the help of the ice pail effect of the sphere is removed from the belt.

                        What you have is a true triboelectric machine. If you were to remove your "supply brush" and just hold a piece of animal fur, or at the other end of the series, a piece of styrofoam, against the belt, I believe you will still see a charge.

                        T he other thing I notice is that your belt is pretty thick (looks like it may be a nylon reinforced neoprene). T hat may be reducing the ability of the charge on the roller to attract the charge on the brush/comb.

                        T hese are the materials that Dick Linder recommends. (Except Dick uses white belt material. T he McMaster Carr number for the belt material is for black, which has been used sucessfully by others)

                        Belt is vinyl laminated nylon (McMaster-Carr 8810K141)
                        T he upper roller is T eflon
                        T he lower roller is nylon

                        T he belt material is only .015" thick. I'm going to order some in the next couple days. if you would like I could send you a piece to experiment with.

                        One question. Did you put the Faraday shield on the supply side or the collection side? It should be on the collection side.

                        You've done some awesome work on this fixture it really looks good. I especially like the way you handled the copper on the brushes.

                        Good luck

                        Glen

                        --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" <drj11642@...> wrote:

                        >
                        > Check out my last 3 photos [drj11642's toys]. I installed the shields and
                        so far no difference. I plan on trying again after I paint all edges with corona dope.
                        >
                        > Doug J
                        >

                      • DOUG
                        Hi Dick; Do you think a 12 discharge is good on a VDG with a 14 terminal? _____ From: VanDeGraaffGenerator@yahoogroups.com
                        Message 11 of 13 , Feb 13, 2012
                        • 0 Attachment

                          Hi Dick; Do you think a 12” discharge is good on a VDG with a 14” terminal?

                           


                          From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of Richard Linder
                          Sent: Sunday, February 12, 2012 7:03 PM
                          To: VanDeGraaffGenerator@yahoogroups.com
                          Subject: [VanDeGraaffGenerator] RE:VDG BEL T MA T ERIAL

                           

                           

                          Hi All:    FYI the best I can determine is the material I used for the belt is McMaster-Carr  8810IK123. It is nylon therefore no appreciable stretch. After a bit of a “run in” the belt rides vey well on a slightly crowned roller. It is white therefore unlikely there is any conductive die used for coloration, It is vinyl which electrostatically proper and is weldable with acetone base plexi cement and the splice remains flexible. B T W he splice should be at an angle so it does not cross the roller all at once. I made two belts for the big VDG, one as a spare. I am still on the first belt after almost three years of lots of demos. 

                           

                          Dick

                           


                          From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of DOUG
                          Sent: T hursday, February 09, 2012 9:36 AM
                          To: VanDeGraaffGenerator@yahoogroups.com
                          Subject: RE: [VanDeGraaffGenerator] Re: Hello Grayco4

                           

                           

                          Hello Glen; T he belt is Mcmaster carr # 8981k112 - Medium-strength Neoprene Rubber, 3/32" T hk, 2"w, 36"l, Black, 30a Duro, Plain Back. I tried some 1/16” of the same stuff and lost 5 microamps .

                          Some interesting results with my VDG test fixture.

                           

                          Parameters;

                          Rollers = 1-1/2” diameter, 18” on center. Pos. is solid aluminum, neg. is acrylic.

                          Belt = 2” wide X 3/32” thick Neoprene.

                          • Brushes = Permanent conductive polyethylene. Surface resistivity: ≤ 102 ohms/sq.  Volume resistivity: < 300 ohms/cm.
                          • T he brushes contact the belt.

                          Belt speed = 412 Rpm. On the belt.

                          With this setup current was 14 microamps.

                          When I switched to saw tooth brass shim stock brushes current dropped to 12 microamps.

                          I also tried a fitness band belt with the polyethylene brushes and current droped to 8 microamps

                          I changed the Pos. roller from solid Alum. T o acrylic with foil wrap and gained 3 Microamps [now at 17 microamps]

                          Changed pos. roller to nylon 6/6, dropped 5 microamps

                          So now Neg. roller is PVC, Pos. roller is acrylic with foil wrap and fixture now is at 19 microamps

                          I was introduced to the conductive film by Prof. Kevin Dunn [http://www.cavemanchemistry.com/kmd.html] he uses it on his Dirod machines.

                          I tried it on the neutralizers on  my wimshurst machines and it worked, so then I used it for the pickups and it also worked, better than the combs!

                          The problem with the usual way of using fine wire on the  neutralizers is that it would scratch the sectors, the film does not.

                          My EMAIL is  drj11642@... if you send me your address I will send a sample of the film to try.

                          PS,

                          I would need a piece of the belt material 2” X about 40” to make a belt for my fixture, that is quite a lot for you to give away!

                          Thank you for your comments.

                          Doug J.

                           

                           

                           


                          From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of GlenR
                          Sent: T hursday, February 09, 2012 7:11 AM
                          To: VanDeGraaffGenerator@yahoogroups.com
                          Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

                           

                           



                          Hello Doug, I have been looking at your photos and I have a couple comments.

                          T he fact that your brushes are actually dragging on the belt indicates to me that you are generating a charge by the triboelectric effect between your brush(s) and the belt. T he way these things are suppose to work is that the belt being in contact with the roller and then being separated creates a charge on that roller, usually positive. (read about an electrophorus) T he brush/comb, which does not contact the belt, has a charge, usually negative, on it. T he charge on the brush/comb ionizes the air between the brush/comb and the belt. T he ionized air provides a path for electrons to flow toward the positively charged roller. T he moving belt is between the brush/comb and the roller and the negative charge attaches to the belt and is conveyed to the upper brush/comb and with the help of the ice pail effect of the sphere is removed from the belt.

                          What you have is a true triboelectric machine. If you were to remove your "supply brush" and just hold a piece of animal fur, or at the other end of the series, a piece of styrofoam, against the belt, I believe you will still see a charge.

                          T he other thing I notice is that your belt is pretty thick (looks like it may be a nylon reinforced neoprene). T hat may be reducing the ability of the charge on the roller to attract the charge on the brush/comb.

                          T hese are the materials that Dick Linder recommends. (Except Dick uses white belt material. T he McMaster Carr number for the belt material is for black, which has been used sucessfully by others)

                          Belt is vinyl laminated nylon (McMaster-Carr 8810K141)
                          T he upper roller is T eflon
                          T he lower roller is nylon

                          T he belt material is only .015" thick. I'm going to order some in the next couple days. if you would like I could send you a piece to experiment with.

                          One question. Did you put the Faraday shield on the supply side or the collection side? It should be on the collection side.

                          You've done some awesome work on this fixture it really looks good. I especially like the way you handled the copper on the brushes.

                          Good luck

                          Glen

                          --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" <drj11642@...> wrote:

                          >
                          > Check out my last 3 photos [drj11642's toys]. I installed the shields and
                          so far no difference. I plan on trying again after I paint all edges with corona dope.
                          >
                          > Doug J
                          >

                        • Richard Linder
                          Doug: You should be thrilled!! Dick _____ From: VanDeGraaffGenerator@yahoogroups.com [mailto:VanDeGraaffGenerator@yahoogroups.com] On Behalf Of DOUG Sent:
                          Message 12 of 13 , Feb 13, 2012
                          • 0 Attachment

                            Doug:  You should be thrilled!!

                             

                            Dick


                            From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of DOUG
                            Sent: Monday, February 13, 2012 2:26 PM
                            To: VanDeGraaffGenerator@yahoogroups.com
                            Subject: RE: [VanDeGraaffGenerator] RE:VDG BELT MATERIAL

                             

                             

                            Hi Dick; Do you think a 12” discharge is good on a VDG with a 14” terminal?

                             


                            From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of Richard Linder
                            Sent: Sunday, February 12, 2012 7:03 PM
                            T o: VanDeGraaffGenerator@yahoogroups.com
                            Subject: [VanDeGraaffGenerator] RE:VDG BEL T MA T ERIAL

                             

                             

                            Hi All:    FYI the best I can determine is the material I used for the belt is McMaster-Carr  8810IK123. It is nylon therefore no appreciable stretch. After a bit of a “run in” the belt rides vey well on a slightly crowned roller. It is white therefore unlikely there is any conductive die used for coloration, It is vinyl which electrostatically proper and is weldable with acetone base plexi cement and the splice remains flexible. B T W he splice should be at an angle so it does not cross the roller all at once. I made two belts for the big VDG, one as a spare. I am still on the first belt after almost three years of lots of demos. 

                             

                            Dick

                             


                            From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of DOUG
                            Sent: T hursday, February 09, 2012 9:36 AM
                            T o: VanDeGraaffGenerator@yahoogroups.com
                            Subject: RE: [VanDeGraaffGenerator] Re: Hello Grayco4

                             

                             

                            Hello Glen; T he belt is Mcmaster carr # 8981k112 - Medium-strength Neoprene Rubber, 3/32" T hk, 2"w, 36"l, Black, 30a Duro, Plain Back. I tried some 1/16” of the same stuff and lost 5 microamps .

                            Some interesting results with my VDG test fixture.

                             

                            Parameters;

                            Rollers = 1-1/2” diameter, 18” on center. Pos. is solid aluminum, neg. is acrylic.

                            Belt = 2” wide X 3/32” thick Neoprene.

                            • Brushes = Permanent conductive polyethylene. Surface resistivity: ≤ 102 ohms/sq.  Volume resistivity: < 300 ohms/cm.
                            • T he brushes contact the belt.

                            Belt speed = 412 Rpm. On the belt.

                            With this setup current was 14 microamps.

                            When I switched to saw tooth brass shim stock brushes current dropped to 12 microamps.

                            I also tried a fitness band belt with the polyethylene brushes and current droped to 8 microamps

                            I changed the Pos. roller from solid Alum. T o acrylic with foil wrap and gained 3 Microamps [now at 17 microamps]

                            Changed pos. roller to nylon 6/6, dropped 5 microamps

                            So now Neg. roller is PVC, Pos. roller is acrylic with foil wrap and fixture now is at 19 microamps

                            I was introduced to the conductive film by Prof. Kevin Dunn [http://www.cavemanchemistry.com/kmd.html] he uses it on his Dirod machines.

                            I tried it on the neutralizers on  my wimshurst machines and it worked, so then I used it for the pickups and it also worked, better than the combs!

                            T he problem with the usual way of using fine wire on the  neutralizers is that it would scratch the sectors, the film does not.

                            My EMAIL is  drj11642@... if you send me your address I will send a sample of the film to try.

                            PS,

                            I would need a piece of the belt material 2” X about 40” to make a belt for my fixture, that is quite a lot for you to give away!

                            T hank you for your comments.

                            Doug J.

                             

                             

                             


                            From: VanDeGraaffGenerator@yahoogroups.com [mailto: VanDeGraaffGenerator@yahoogroups.com ] On Behalf Of GlenR
                            Sent: T hursday, February 09, 2012 7:11 AM
                            T o: VanDeGraaffGenerator@yahoogroups.com
                            Subject: [VanDeGraaffGenerator] Re: Hello Grayco4

                             

                             



                            Hello Doug, I have been looking at your photos and I have a couple comments.

                            T he fact that your brushes are actually dragging on the belt indicates to me that you are generating a charge by the triboelectric effect between your brush(s) and the belt. T he way these things are suppose to work is that the belt being in contact with the roller and then being separated creates a charge on that roller, usually positive. (read about an electrophorus) T he brush/comb, which does not contact the belt, has a charge, usually negative, on it. T he charge on the brush/comb ionizes the air between the brush/comb and the belt. T he ionized air provides a path for electrons to flow toward the positively charged roller. T he moving belt is between the brush/comb and the roller and the negative charge attaches to the belt and is conveyed to the upper brush/comb and with the help of the ice pail effect of the sphere is removed from the belt.

                            What you have is a true triboelectric machine. If you were to remove your "supply brush" and just hold a piece of animal fur, or at the other end of the series, a piece of styrofoam, against the belt, I believe you will still see a charge.

                            T he other thing I notice is that your belt is pretty thick (looks like it may be a nylon reinforced neoprene). T hat may be reducing the ability of the charge on the roller to attract the charge on the brush/comb.

                            T hese are the materials that Dick Linder recommends. (Except Dick uses white belt material. T he McMaster Carr number for the belt material is for black, which has been used sucessfully by others)

                            Belt is vinyl laminated nylon (McMaster-Carr 8810K141)
                            T he upper roller is T eflon
                            T he lower roller is nylon

                            T he belt material is only .015" thick. I'm going to order some in the next couple days. if you would like I could send you a piece to experiment with.

                            One question. Did you put the Faraday shield on the supply side or the collection side? It should be on the collection side.

                            You've done some awesome work on this fixture it really looks good. I especially like the way you handled the copper on the brushes.

                            Good luck

                            Glen

                            --- In VanDeGraaffGenerator@yahoogroups.com, "drj11642" <drj11642@...> wrote:

                            >
                            > Check out my last 3 photos [drj11642's toys]. I installed the shields and
                            so far no difference. I plan on trying again after I paint all edges with corona dope.
                            >
                            > Doug J
                            >

                          • drj11642
                            Have any of you VDG builders tried BICROFIBER for belt material?
                            Message 13 of 13 , Aug 25 7:20 AM
                            • 0 Attachment
                              Have any of you VDG builders tried BICROFIBER for belt material?
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