Not cheap and prone to creep but Teflon is basically the best negative source (pvc will also work great) and nylon66 or nylon 6.6 is I think the easiest and best positive source. You really need nylon 66 and not nylon 6,nylon 6 will not work. You can test for nylon 66 because it has a higher melt temperature compared to nylon 6. Also you may need to turn on a lathe or sand the outer edge/diameter/circumference of the raw round stock because the surface could be contaminated with something from extruding the material (as I found out on my stuff)?

The for me famous Richard (Dick) Linder used the Teflon nylon combo if memory serves me well

As a side note avoid anything black because it is likely to contain carbon or graphite which conducts electricity pretty well at high voltages

Re: Is our group still alive?

#41

I'm doing fine here, thank you. :)

Re: Is our group still alive?

#40

Hello ! I think our group is deeply sleeping, but is not dead.?

Re: Is our group still alive?

#39

开云体育

I am fine, just have not been active with VDG for a very long time. Life gets in the way

Regards Elmer?

good materials to use with latex exercise bands

#38

Looking for recommendations for bottom and top roller material for use with the cheap 600mm 25mm exercise bands.?

?

thanks?

Re: Is our group still alive?

#37

yes - thats two of us!

5 photos uploaded #photo-notice

Group Notification

#36

The following photos have been uploaded to the VDG varia photo album of the [email protected] group.

By: Antivolt <lyonelb@...>

23 photos uploaded #photo-notice

Group Notification

#35

The following photos have been uploaded to the VDG Phywe photo album of the [email protected] group.

By: Antivolt <lyonelb@...>

Is our group still alive?

#34

Hi Friends?

For about three years no more messages came?

Is everybody ok?

Solid state tesla coils

#33
Edited

Wondering if anyone has taken a chance on a solid state tesla coil, either as a kit or fully assembled.??This technology has come a long ways and now seems to generate pretty big sparks comparable to the time-tested spark gap method coils.? ?

?

I use the rule of thumb that the spark length should be around a 1:1 ratio to the secondary coil length.

?

As an example, here's one from Ebay that claims such a ratio but it's so easy to fake pictures these days.? It's also only 8 1/4 inches tall.? It's very easy to think it's much bigger than it really is.? It's pretty expensive for such a small coil.? ?And it's called a DIY kit, so I wonder just how much assembly is required.? Is the coil factory wound?

?

Another thing, and this is completely unbelievable, is the?claimed average rated power of 250 watts!? ?Looking at the wallwart PS in another listing gives the voltage as 18 volts.? It must be a switcher, but I still can't see it producing much more than 4 amps, so that's not even 100 watts.

AC 110V/220V DIY SSTC Tesla Coil Music High Power Plasma Horn Speaker Electronic | eBay

Re: Van de Graaff prime season; where is everybody?

Steven Greenfield AE7HD

#32

In western Washington state, now is far from prime time for electrostatics. It alternates between sometimes frosting in the morning, or raining, or thick fog and warm afternoons.

I have a hamster ball that I've covered in aluminum tape and glued a large PVC connector to. The goal is to make a large VDG. Although I think I'd like to make an exchangeable base, so I can also carry it around when I'm in my Mad Doctor outfit at sci fi conventions.

Steve Greenfield AE7HD

Lichtenberg Figures

#31
Edited

click on the google photo image when it comes up for a larger version.

? The top two figures that look like fireworks are from positive discharges and the bottom five are from negative discharges. An aluminum cigar tube was placed open end down on the plastic and a charged pie tin was brought near the cigar tube until a spark discharge occurred. The cigar tube was then removed and the plastic was dusted with baking power. The pie tin had an insulating handle and was charged with a Van de Graaff generator.??This is almost exactly how G. C. Lichtenberg did it in 1777 only, he used and electrophorus for charging, different powders for dusting and gum-lac, resin for the plastic surface.

? I'm now charging a 2 nF salt water cap and discharging it through the same cigar tube placed on 2 mm thick acrylic sheet. I started grounding the cigar tube before I pick it up and discovered that this grounding was causing a smaller second discharge of opposite polarity to the first.

These next two photos are with out grounding the cigar tube before removal. Positive on the left and negative on the right.

This photo is with grounding the cigar tube before removal.

? The small inner ring of the positive discharge is the second negative discharge.?The negative discharge on the right, has an inner positive discharge that is almost as large as it is. This is because positive figures are much larger than negative for the same voltage.

? The following two photos show positive figures over 10 cm in diameter using the 2 nF cap on a 11 x 15.5 cm acrylic block 24 mm thick. The count was about 12 seconds charging time. Assuming the VDG is a constant current source of 4.5 uA (which is only approximate because of leakage at these high voltages) the voltage is about 27 kV.

? This is one of the more “artsy” figures. Positive discharge thru 48 mm diameter metal sphere resting on 2 mm thick acrylic with grounded back plane. After discharge the sphere was accidentally grounded and rolled a little toward the upper left. Blobs of negative discharge can be seen as the sphere rolled.

click on image for larger view.

Re: Van de Graaff prime season; where is everybody?

#30

Work and , building a new r/c fixed wing drone with a planked wing design, iNAV autopilot .? ? Hopefully I will build a new 5ft VanDeGraaff generator in time for Halloween 2020

Show quoted text

On Feb 21, 2020 9:51 PM, "Hank Riley via Groups.Io" <n1ltv@...> wrote:

This is the peak of the season for electrostatics with low humidity and less competing outdoor activities.

Where is everybody?? Let's have a little noise on this group!? Be the first to post (other than moi) in 2020 before the month ends.