Re: Off topic Jacobs ladder qustion

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Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>

At 08:10 PM 10/16/2005, you wrote:
> Original poster: "bmcpeak" <bmcpeak33@xxxxxxxxxxx>
>
> Hello, Group,
> While working on my Coil I am building a Jacobs ladder ( need a HV fix :)
> My question is ... I have located some large O.D. Glass Vases to use 
> for a tube for the electrodes. But I want to cut the bottom off of 
> the vase, can anyone give advice on doing this to a round object. As 
> last resort I could drill holes for the electrodes.

With the right drill, this is easy.
The drill looks like a tube with diamond grit on the end.  Or, you 
can use a brass tube and a slurry of carborundum grit.

Likewise, sawing uses a diamond blade (there are dremel tools for 
cutting glass too).

if you're a sporting man, and you have a sufficient budget for 
mistakes, you can also do it by:
1) carefully scoring around the glass with a glass cutting scribe 
(learn from my mistakes.. do NOT buy the cheapest glass cutter.. 
spend $4, not $2)
2) tying a piece of string soaked in appropriate fuel (I've seen 
kerosine, gasoline, and alcohol used for this) around the scribed line.
3) ignite the string
4) when it's burned down, plunge the glass into cold water
5) It will crack along the scribed line

You don't necessarily need to do Step 4...

A piece of nichrome wire around the bottle will also work.. the idea 
is to create a localized thermal stress.

Practice on wine bottles.  They're free and uniformly round, which 
makes it easier.

A real sportin' type, with HV and big caps, can try doing an 
exploding wire around the bottle.  I've had mixed results with this, 
but I was trying to shatter words into glass plates.


You might also get someone to do it for you.  Most places that do 
glass as their primary business (as opposed to just selling window 
glass at the hardware store) can cut/drill glass. They do all kinds 
of stuff like this (sawing kidney shaped glass table tops, for instance)

That's what I'd do.. get the phone book out and look up glass & mirror places

But, all in all, go to the guy with the diamond saw... seconds later 
you'll be done.

> Or use an acrylic tube but how likely would this material be to melt?

Depends on how close the tolerances are... The UV from the spark does 
"bad things" to the acrylic after a while, as do the nitrogen oxides 
from the spark.


The other alternative you should be aware of is buying a length of 
glass "process tubing", which is available in a variety of diameters 
and lengths.  There are also all sorts of nifty clamps and what not 
to clamp onto it.




> Brad McPeak