Hi Jay, the belts I use are deceptively cheap. You can find them at
wall-mart for around $8 a pack - look for latex exercise bands. You can get
a pack of 3 4ft long 6in wide with 3 resistance levels (thickness), or a 1
pack of 6ft long 6in wide at max resistance.
What I do is cut the bands into strips 2 inches wide (widthof my rollzer),
then size them about 1.8 * the distance between the middle of the rollers.
This gives a 10% stretch ratio but you can go more to 20% if you like.
The trick to joining them is to cut the ends at 45 degree angles and mark
another 45 degree line 1 inch from the end (on both sides). Make sure you
cut the ends with opposite angles!
Kind of like this (first angle is the cut the second is the reference line
for applying the glue and overlapping the ends).
\=\=======/=/
Then use 'rubber/latex cement' and apply to each end CAREFULLY about an
inch inwards (to where the additional line is marked). When you do this the
latex will want to curl, so droop it over a table edge so it can't roll
back on itself.
Now let the glue dry for at least 15-20 minutes, but not longer than one
hour. Then carefully arrange the two ends so you don't have a belt twist
and overlap the edges and press together. This is contact cement so be
extremely careful you have to align it pretty accurate.
For really long belts just join multiple sections together, I did this on
my 6 foot VDG with two sections and it works great (still works, even
though the belt has taken a beating from misaligned brushes).
I then clean my belts with liberal amounts of rubbing alcohol (98%) using a
saturated paper towel or cloth. Try to avoid the areas where the edges are
joined you don't want it on the glue.
Once the alcohol evaporates just check for any bits of crud and remove them
gently.
Now for rollers I use metal tape for neutral and PVC tape for negative.
I've tried all the other options including teflon but it's never beaten
that combo. i used cheapo $7 nylon bed casters from Menards or other
hardware stores. They are already made with a taper out taper in so it
auto-aligns the belt in almost all cases.
I just made a new 3 foot POSITIVE VDG today and it was working but suddenly
no charge, so I probably have some crud in the works or the belt needs a
clean. So when I take it apart I'll post pics of the belt.
Hope that helps, any questions let me know!
Cheers!
Matt Sweeney
On Mon, Aug 24, 2015 at 10:08 PM, jhowson4@xxxxxxxxxxx <jhowson4@xxxxxxxxxxx
> wrote:
> Matt,
> I for one would be interested in learning more about your style of
> belts. We built a vdg with a 22inch sphere for a museum when i was in
> college, and the belt coming apart was always a problem. It was neoprene i
> believe, its been a while. We were getting sparks, maybe 30-40 inches off
> it when it was winter and humidity was low. We did have a trick for helping
> with the corona around the sphere edge hole. We took aluminium tape and
> applied it on the tube, such that it went up into the sphere. But it was
> still isolated, as their was a grommet type thing around the inner edge. It
> seemed to reduce breakdown around that edge signifigantly. But was tricky
> to get the location just right.
>
> Cheers, Jay Howson
> ------ Original message------From: Matthew Sweeney Date: Mon, Aug 24, 2015
> 10:37 PMTo: Tesla Coil Mailing List;Cc: Subject:Re: [TCML] Seaching for
> Mike Delosier
> Here are some videos from my older models. I did build a six foot
> modelwith a 14inch sphere running at 10x power delivery. It was a beast
> butcaused me much trouble due to extremely high electrical field
> potentialsaround the sphere opening. I used steel Ikea bowls and they just
> wanted tobuckle when I radius them. I have made a few corona rings that
> help, butI'm not so good at joining the two ends and soldering a nice
> smooth joint =(All my devices are completely home built including PVC form
> (well Ipurchased the PVC), belts, rollers, corona tubes, comb assemblies
> andvarious discharge rods. Of course the motor and hemispherical bowls
> wereitems I could not make myself. Note all devices are extremely quiet- I
> usedhigh quality bearings everywhere and drill press for accuracy.My 6
> foot high-power version was insane throwing off continuous charges upto 40
> inches in length which seems way more than possible using a 14inchsphere.I
> have cannibalized my large generator and am building two 3 foot
> dual-polepositive/negative generators in an attempt to 'double' the
> voltagegradient. We shall see!Next project is a new Thunderstorm built very
> high quality and fullself-contained re-pumping. After that it's either a
> giant Van De Graaff ora tesla coil. I can build belts up to 6inches wide
> and many 10's of feetlong, but I cant yet built large spheres over 14inches
> =(
> https://www.youtube.com/watch?v=Fb-tWeJ3Z0Uhttps://www.youtube.com/watch?v=ABKCGXuJDlwhttps://www.youtube.com/watch?v=eRsl6rs2cEohttps://www.youtube.com/watch?v=Hs3K0C1CeVkhttps://www.youtube.com/watch?v=O3CSO9fIQu0https://www.youtube.com/watch?v=o8ZHrSiVEXshttps://www.youtube.com/watch?v=v6KdIKDr4Tchttps://www.youtube.com/watch?v=em67iXD5-ms
> (voltage specified is likelyincorrect)
> https://www.youtube.com/watch?v=I37C5qWRi3A (voltage specified is
> likelyincorrect)https://www.youtube.com/watch?v=cQTRKiYsCEc (just for
> fun).Any questions please let me know, I'm certainly no expert but have
> learneda few tricks to provide excellent charge rates, smooth operation,
> and hugereduction in expensive (my 6ft long 2ft wide belts are only $3 each
> andwork better than any other I have tried).Thanks!Matt SweeneyOn Sat, Aug
> 22, 2015 at 9:54 PM, wt5y wrote:>>>> Cornel dubilier 942c20p15k-f .15uf
> 2000v caps can be had $4.99 ea from> easternvoltageresearch.com>> Sorry
> don't know mike. Someone else may.> If you don't mind can I see some of
> the van DE Graaf you've made ie> website,youtube? And what are Kelvin
> thunderstorm project, will Google it> but never heard of it.>> John cooper
> WT5YWt5y@xxxxxxxxx> Sent from my Samsung GALAXY S5™, a Cricket 4G LTE
> smartpho>> -------- Original message --------> From: Matthew Sweeney >
> Date: 08/22/2015 16:10 (GMT-06:00)> To: tesla@xxxxxxxxxx> Subject:
> [TCML] Seaching for Mike Delosier>> Hello, I recently joined this mailing
> because I didn't know it existed. I> don't make tesla coils any more but I
> produce large Van De Graff generators> and simple kelvin thunderstorm
> projects to amuse myself and keep my nephews> amazed.>> Anyway I visited my
> local Axe-MAn today and learned that they have a> customer named Mike
> Delosier who lives in minnesota and has some> impressive coils.>> I am
> hoping very much to contact Mike but I have not been able to find his>
> e-mail address. I don't see any recent posts with his name so maybe he is>
> not a member anymore?>> So, if anyone knows him, I would be delighted to
> send him an email.> Alternatively he can send ME an e-mail as to be less
> intrusive:> msweeney23@xxxxxxxxx>> I did build several decent coils over
> 20 years ago with home made plate> class capacitors and a horribly
> inefficient stationary spark gap. I didn't> have any protection circuitry
> in place but somehow my HV transformers> survived, however my capacitor
> eventually exploded.>> Now I have three perfect 15,000v 250ma NST's just
> sitting waiting for a> purpose - so I think it's time to start planning a
> new build. I have never> built a proper solid state coil and am considering
> this option. But a> traditional rotary spark-cap coil with high-voltage
> capacitors would be> much less effort. The secondary will be 5 Feet and
> using enameled magnet> wire.>> I'm looking for good sources of (cheap) high
> voltage capacitors and much> info on recent developments in the field. I
> especially am interested in> inductor usage to prevent spikes back to the
> NST. Also I need some advice> on secondary wiring cable is there a
> preferred variety for recent coils?> Ill use copper tubing for primary. I
> may also build my own rolled> capacitors but I'm thinking obtaining newer
> HV caps in a bank may actually> be cheaper.>> If there other members in the
> Minnesota/Wisconsin I would also like to> connect. I'm desperate to find a
> powerful coil to blow my nephews minds =)>> Thank you for any help you can
> provide. I'll be reviewing the lists looking> for new info also but direct
> contact for any suggestions would be welcomed.>> Regards,>> Matt Sweeney>
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